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GLOSSARY

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Glossary Search Results

4198 terms found.

C3, the third component of complement, can be activated by either antibody binding or by microbial polysaccharides.

SPI

Self-Paced Instruction

³H-uridine

³H-uridine is a radioactive form of the nucleoside uridine that has a radioisotope of the hydrogen atom embedded in its molecular structure. Uridine is a nucleoside component of RNA; thus, ³H-uridine is incorporated into RNA and can be measured to determine RNA synthesis.

Bacillus

Bacillus is a large genus of gram-positive, spore-bearing, rod-like bacteria. They are widely distributed in soil and air (usually as spores). Most feed on dead organic material and are responsible for food spoilage.

Escherichia coli

Escherichia coli is a species of bacteria that lives in the intestines of healthy humans and animals. It is generally not pathogenic, but the O157:H7 strain, transmitted through improperly prepared infected meat or contact with infected feces, produces a powerful toxin that can cause severe illness.

Lactobacillus

Leptotrichia

Leptotrichia is a genus of anaerobic, nonmotile bacteria containing Gram-negative, straight or slightly curves rods, 5 to 4 µm in length, with one or both ends rounded, often pointed. Granules are distributed evenly along the long axis, and one or more large granules may localize near the end of the cell. Branched or clubbed forms do not occur. Two or more cells may join together to form septate filaments of varying length. In older cultures, filaments up to 200 µm may form and twist around each other. These organisms occur in the oral cavity of man.

Neisseria

Neisseria is a genus of aerobic to facultatively anaerobic bacteria (family Neisseriaceae) containing Gram-negative cocci, which occur in pairs with the adjacent sides flattened. These organisms are parasites of animals.

Propionibacterium acnes

Propionibacterium acnes is a bacteria commonly found in acne pustules. Propionibacterium is a genus of non-motile anaerobic, gram-positive bacteria that are found on the skin of humans, in the intestinal tract of humans and animals, and in dairy products.

Rhodotorula rubra

Rhodotorula rubra is a common species of yeast, easily identified by its orange color and commonly found in air and water contaminants.

Serratia marcescens

Serratia is a genus of motile, gram-negative bacilli capable of causing infection in humans, including bacteremia, pneumonia and urinary tract infections. Serratia marcescens, the type species, is found in water, soil, milk, foods, silkworms and other insects.

Staphylococcus aureus

Staphylococcus aureus is a common bacterial species found on nasal mucous membranes and the skin (hair follicles). S. aureus causes pneumonia, endocarditis, and other infections, as well as food poisoning; it is also a main cause of infections in burn patients.

Veillonella

Veillonella is a genus of nonmotile, nonsporeforming, anaerobic bacteria (family Veillonellaceae) containing small (0.3 to 0.5 µm in diameter), Gram-negative cocci which occur as diplococci and in masses. Carbon dioxide is required for growth, and carbohydrates are not fermented. These organisms are parasitic in the mouth and the intestinal and respiratory tracts of man and other animals. They produce serologically specific endotoxins (lipopolysaccharides) which induce pyrogenicity and the Schwarzman phenomenon in rabbits.

1,25-dihydroxyvitamin D

Vitamin D acts in the body to increase calcium absorption from the gastrointestinal tract and also helps control calcium deposition in the bone. The natural vitamin D results from ultraviolet irradiation of a substance in the skin. This substance must then be converted to 1,25 dihydroxyvitamin D by the liver and kidneys to have an effect in the body.

1-G

1-G (one-G) refers to the gravity force found on Earth.

1-methylhydrazine

Methylhydrazine is a toxic compound primarily used as a high-energy fuel in military applications, as a rocket propellant and fuel for thrusters, and as fuel for small electrical power generating units.

15N-Glycine

¹⁵N-glycine is a nonradioactively labeled form of the amino acid glycine, which is found in protein. The nitrogen-15 (¹⁵N) isotope allows the concentration of glycine from a known source to be detected and measured in urine or saliva samples to evaluate protein metabolism.

15N-glycine method

The 15N-glycine method is used to measure the synthesis rate of protein in the body. Glycine is gelatin sugar composed of carbon, hydrogen, and nitrogen. Instead of the common 14N nitrogen isotope, the less common 15N isotope of nitrogen is used as part of the glycine molecule. 15N makes up about 0.365% of natural nitrogen. Glycine is digested by the body and part of the 15N is used to synthesize new protein molecules, while the unused nitrogen is excreted in the urine. The difference between the excreted and ingested amounts of 15N-glycine determines the synthesis rate for protein.

17-hydroxycorticosteroid

17-Hydroxycorticosteroid refers to any of the hormones, such as cortisol, secreted by adrenal glands and measured in the urine in a test for determining adrenal function and diagnosing hypo- or hyperadrenalism.

17-ketosteroid

17-Ketosteroid is a steroid containing a ketone group which is commonly measured in blood and urine to aid in the diagnosis of Addison's disease, Cushing's syndrome, stress and endocrine problems.

2,3-diphosphoglycerate (2,3 DPG)

2,3-diphosphoglycerate (2,3 DPG; now known as 2,3-biphosphoglycerate) is an important regulator for the affinity of hemoglobin for oxygen. It synthesizes within red blood cells (RBCs). This synthesis represents a major reaction pathway for the consumption of glucose in RBCs. Note that when glucose is oxidized by this pathway the RBC loses the ability to gain 2 moles of adenosine triphosphate (ATP) from glycolytic oxidation of 1,3-biphosphoglycerate to 3-phosphoglycerate via the phosphoglycerate kinase reaction. The synthesis of 2,3-biphosphoglycerate in RBCs is critical for controlling hemoglobin affinity for oxygen. It plays a major role in making adjustments in oxygen delivery, over a period of several hours to one day. Thus, it sets the level of oxygen delivery, ensuring that delivery remains sufficient and almost constant despite modest variations in oxygen availability.

3-methyl histidine

3-methyl histidine is an amino acid that is one of the constituents of the major proteins (actin and myosin) of skeletal muscle. It is excreted in the urine when actin and myosin are metabolized, and it is not used to form new protein. Therefore, the amount of 3-methyl histidine in urine is considered an indicator of muscle protein degradation.

3-methyl-d3-histidine

3-methyl-d3-histidine is a version of 3-methyl-histidine containing three atoms of deuterium (a stable isotope of hydrogen) in the methyl group. 3-methyl-d3-histidine is used as a tracer to follow the path of muscle protein degradation in the body.

3H-methyl-thymidine

3H-methyl-thymidine is a thymidine molecule, one of four “code” substances in deoxyribonucleic acid (DNA), made radioactive by substituting tritium (3H) for ordinary hydrogen (1H).

Amperes

A&E

Architectural and Engineering

A&R

Automation and Robotics

A-D

Analog to Digital

A-E

Activity Elements

A-G

Air-To-Ground

A-L

Airlock

A-V

Analog-Video

A/C

Aircraft

A/D

Analog to Digital

Air to Air

Associate Administrator (NASA)

AA-OSS

Associate Administrator - Office of Space Science

AAHF

Aquatic Animal Holding Facility

Aberration

Aberration refers to straying from the normal situation; deviant development or growth.

ABS

Animal Biotelemetry System

Abscess

An abscess is a circumscribed collection of pus appearing in an acute or chronic localized infection, and is associated with tissue destruction and swelling.

Absolute Lymphopenia

Absolute Lymphopenia is the reduction in the total number of lymphocytes in the blood.

Absolute Neutrophilia

Absolute Neutrophilia refers to the increase in the total number of leukocytes in the blood as well as an increased percentage of neutrophils.

Absorbed dose

An absorbed dose is the quantity of radiation received per unit of mass within a given period of time. The unit is the gray (Gy), although it is often measured in rads (1 rad = 0.01 gray).

Absorptance

Absorptance is the ratio of absorbed to incident radiation.

Absorptiometer

An absorptiometer is a device that measures photon radiation. An absorptiometer consists of at least three essential components: (1) a source of electromagnetic (photon) radiation in the proper energy region, (2) a cell that is transparent to the radiation and that can contain the sample, and (3) a detector that can accurately measure the intensity of the radiation after it has passed through the cell and the sample.

Absorptiometry

Absorptiometry is a technique that measures the amount of radiation absorbed by any substance or chemical constituent of blood, urine or other body fluid that is analyzed (analyte). Essentially, the amount of absorbed radiation increases with the concentration of the analyte and with the distance through the analyte that the radiation must travel (the cell path length). As radiation is absorbed in the sample, the intensity of the radiative beam decreases. By measuring the decreased intensity through a fixed-path-length cell containing the sample, it is possible to determine the concentration of the sample. Because different analytes absorb at different wavelengths (or energies), the device that measures the radiation must be capable of controlling the wavelength of the incident electromagnetic (photon) radiation. When measuring bone mineral content, the radiation sources used emit radiation within a narrow wavelength band.

Absorption

Absorption is the uptake of fluids or other substances by the tissues of the body. Digested food is absorbed into the blood and lymph from the alimentary canal. Most absorption of food occurs in the small intestine.

Alternating Current

ACA

Attitude Control Assembly

Acceleration

Acceleration is the rate of change of velocity with respect to time.

Accelerometer

An accelerometer is a device used to measure acceleration, the rate of change of velocity with respect to time.

Accessory cell

An accessory cell is a blood cell, usually a monocyte, that secretes a substance (such as interleukin-1) required for activation of lymphocytes in the immune response.

ACCU

Audio Central Control Unit

ACD

Architectural Control Document

Acetaminophen

Acetaminophen is a medication commonly used to reduce pain or fever.

Acetylcholine

Acetylcholine is released at nerve endings to pass on a nerve impulse to the next nerve or to initiate muscular contractions. The released acetylcholine is rapidly broken down by the enzyme acetylcholinesterase to allow the transmission of following (subsequent) impulses.

Acetylcholinesterase

Acetylcholinesterase is an enzyme that breaks down the neurotransmitter acetylcholine (a chemical which initiates muscular contraction) into choline and acetic acid, rendering it inactive or unable to transmit a signal, therefore, stopping or regulating the nerve signals.

Acetylene (C2H2)

Acetylene is a colorless, odorless hydrocarbon gas. Its formula is C2H2, and in high concentration of 40 volumes per cent and higher it has the effect of an anesthetic.

Acetylene concentration

Acetylene is a colorless explosive hydrocarbon gas, and is used as an anesthetic in concentrations of 40 volumes per cent and higher.

ACF

Animal Care Facility

ACGIH

American Conference of Government Industrial Hygienists

Achilles tendon

The Achilles tendon is a fibrous band that connects the triceps surea (the calf muscle) with the calcaneus (heel bone).

Acid citrate dextrose

Acid citrate dextrose contains trisodium citrate (dihydrate), citric acid and glucose. It is an anticoagulant agent that keeps blood from clotting, or forming into a solid or gel.

Acid phosphatase

Acid phosphatase is an enzyme with acidic pH optimum, that catalyzes cleavage of inorganic phosphate from a variety of substrates. Found particularly in lysosomes and secretory vesicles. Can be localized histochemically using various forms of the Gomori procedure.

Acinetobacter calcoaceticus bio. anitratus

Acinetobacter calcoaceticus bio. anitratus is a species of bacteria originally found in environments containing quinic acid. It is a nonmotile, aerobic bacterium in the form of gram-negative short rods and does not produce spores. One of its strains is commonly found in the genitourinary tract of humans.

Acini

Acini are the small gas exchange regions of the lung.

Acoustic

Acoustic means of or relating to sound, the sense of hearing or the science of sound.

ACPL

Atmospheric Cloud Physics Lab

ACR

Active Cavity Radiometer

ACS

Aft Crew Station

ACS

Attitude Control System

ACT

Actual

Actifed

Actifed is a trademark for a fixed-combination drug containing an adrenergic vasoconstrictor and an antihistamine.

Actinometry

Actinometry is used to measure the ability of radiant energy in the visible and ultraviolet spectral regions to produce chemical changes. Actinometry can also measure the direct heating power of the sun's rays.

Action potential conduction velocity

The action potential conduction velocity is the measure of the velocity of a nerve impulse (or action potential) from a specified initial point to an end point on a nerve fiber. The change in voltage that occurs across the membrane of a nerve or muscle cell when a nerve impulse is triggered is called an action potential; it is caused by the passage of charged particles across the membrane (depolarization).

Activate

To activate is to set in motion; to make active.

ACTP

Acceptance and Certification Test Plan

Actuator

An actuator is a mechanical device used to move or control an object.

ACUC

Animal Care and Use Committee

Acuity

Acuity is clarity or distinctness of hearing or sight.

Ad libitum

Ad libitum means without restraint.

ADC

Analog Digital Converter

ADCLS

Automated Data Collection/Location System

Adductor

An adductor is any muscle that draws a body part toward the median plane of the body.

Adductor longus

The adductor longus is one muscle of the inner thigh. It is the muscle that allows the thigh bone (femur) to move.

Adenosine monophosphate (AMP)

Adenosine monophosphate (AMP), more specifically known as adenosine-5'-monophosphate or adenylic acid, functions as the basic structure for ATP and ADP, both of which serve as short term energy stores for the cell.

Adenosine triphosphatase (ATPase)

Adenosine triphosphatase (ATPase) is an enzyme that hydrolyzes adenosine triphosphate.

Adenosine triphosphate (ATP)

Adenosine triphosphate (ATP) is a nucleotide that is of fundamental importance as a carrier of chemical energy in all living organisms. ATP can undergo hydrolysis, a reaction triggered by ATPase, which releases a large amount of energy that is used to fuel such biological processes as muscle contraction or the active transport of ions and molecules across cell membranes, or the synthesis of biomolecules.

Adenovirus

Adenoviruses are viruses containing double-stranded DNA. They cause latent infections in mammals and birds of the upper respiratory tracts, and produce symptoms resembling those of the common cold.

ADM

Archive Data Manager

ADP

Acceptance Data Package

ADP

Automatic Data Processing

ADR

Ames Double Rack

Adrenal

Adrenal means near or upon the kidney; denoting the adrenal glands (a pair of endocrine glands) located on the surface of the kidneys. These glands are responsible for the secretion of adrenalin and other regulatory hormones.

Adrenal cortex

The adrenal cortex is the outer region of the adrenal gland, in which several steroid hormones are produced.

Adrenal glands

Adrenal glands are a pair of endocrine glands located on the surface of the kidneys that are responsible for the secretion of adrenalin and other regulatory hormones.

Adrenalectomized

Adrenalectomized (or adrenalectomy) means having one or both adrenal glands removed.

Adrenergic

Adrenergic means activated by, characteristic of, or secreting epinephrine (adrenaline) or substances with similar activity. The term is applied to nerve fibers that liberate epinephrine at a synapse when a nerve impulse passes, such as the sympathetic fibers.

Adrenergic receptors

Adrenergic receptors are receptors of nerve cells or fibers of the nerve systems that employ norepinephrine or epinephrine as their neurotransmitter (to transmit a signal from one nerve cell to the next).

Adrenocortical

Adrenocortical means of, relating to, or derived from the cortex of the adrenal glands.

Adrenocorticotropic hormone (ACTH)

Adrenocorticotropic hormone (ACTH) is a hormone synthesized and secreted by the anterior pituitary gland. ACTH is produced in response to stress and controls the secretion of certain hormones by the adrenal glands.

ADSF

Advanced Directional Solidification Furnace

ADT

Abstract Data Type

AEI

Analytical Experiment Integration

AEM-II

Animal Enclosure Module - Mark II

AEPI

Atmospheric Emission Photo Imaging

Aerobic

Aerobic means living in air. Aerobic can also describe a type of cellular respiration in which foodstuffs (usually carbohydrates) are completely oxidized into carbon dioxide and water with the production of chemical energy, in a process requiring atmospheric oxygen.

Aerobic (exercise) capacity

Aerobic capacity, or aerobic exercise capacity, is the capacity of the respiratory and cardiovascular systems to deliver oxygen to working muscles.

Aerodynamic size

Aerodynamic size is the size of a particle when it is moving through air.

Audio Frequency

AFB

Air Force Base

AFC

Automatic Frequency Control

AFD

Orbiter Aft Flight Deck

Afebrile

Afebrile means without fever.

Afferent

Afferent is a general term applied to nerves or blood vessels that means nerve signals or blood are traveling from the peripheral to the center of the body.

AFOS

Automation of Field Operations and Services

AFT

Aerodynamic Flight Test

AFTE

Autogenic Feedback Training Experiment

Agar

Agar is an extract of certain seaweeds that forms a gel suitable for the solidification of liquid bacteriological culture media.

AGC

Automatic Gain Control

Agglutinate

Agglutinate means to cement or unite together.

Agglutination

Agglutination is the clumping or sticking together of cells, such as red blood cells or bacteria, so that they form a visible pellet-like clump. Agglutination can be a reaction of the red blood cells, closing an injury in the skin, or by antibodies.

Aggregate

An aggregate is a group of cells that are attached together.

Aggregation

Aggregation means to unite or come together in a mass or cluster.

Agonist

Agonist describes a drug, hormone or transmitter substance that forms a complex with a receptor site and triggers an active response from a cell (in other words, a drug capable of initiating actions is an agonist). Also, an agonist is a muscle whose active contraction causes movement of a part of the body.

AGS

Antigravity Suit

AGSIEI

Anti-G Suit Inflight Evaluation Instrumentation

Action Item

Analog Input

Artificial Intelligence

AI&T

Assembly, Integration and Test

AIBS

American Institute of Biological Sciences

AICS

Action Item Control System

AIL

Authorized Inventory List

Accelerator

Airlock

Alanine

Alanine is a nonessential amino acid found in many food protein sources as well as in the body.

Albumin

Albumin is a type of simple protein widely distributed throughout the tissues and fluids of plants and animals; it is characterized by being soluble in water but forms insoluble coagulates when heated. Albumins occur in egg white, blood, milk, and plants.

Aldosterone

Aldosterone is the principal electrolyte-regulating steroid secreted by the adrenal cortex; it controls excretion of potassium by the kidneys and thereby maintains the balance of sodium and water in the body fluids.

ALFE

Astronaut Lung-Function Experiment

Algorithm

An algorithm is any mechanical or repetitive procedure used in the management of health problems.

Aliquot

An aliquot is a portion of the whole. When a sample is separated into aliquots, each portion is of equal weight or volume.

Aliquote

Aliquote (verb) is to divide into equal portions.

Alkaline phosphatase

Alkaline phosphatase is an enzyme that catalyses the hydrolysis of phosphoric acid esters under conditions of alkaline pH. In humans, the level of alkaline phosphatase in the blood is measured as part of the assessment of liver function. In the blood, the enzyme also breaks down phosphates required for mineralization of bone. There are two distinct forms of the enzyme, liver alkaline phosphatase and bone alkaline phosphatase.

Alkalosis

Alkalosis is an abnormal condition of body fluids, characterized by a tendency toward a pH level greater than 7.44, usually caused from an excess of alkaline bicarbonate or a deficiency of acid. Respiratory alkalosis may be caused by hyperventilation, resulting in an excess loss of carbon dioxide and a carbonic acid deficit. Metabolic alkalosis may result from an excess intake of or retention of bicarbonate, loss of gastric acid in vomiting, potassium depletion or any stimuli that increases the rate of sodium-hydrogen exchange.

Allantoic fluid

Allantoic fluid is fluid of the allantois, a fetal membrane developing from the hindgut (or yolk sac, in man). In man the allantois is vestigial; in mammals it contributes to the formation of the umbilical cord and placenta, and in birds and reptiles it lies close beneath the porous shell and serves as an organ of respiration.

Allergen

An allergen is any anitigen that causes allergy in a hypersensitive person. Allergens are diverse and affect different tissues and organs. Examples of allergens include pollen, fur, feathers, dust and mold.

Alloy

An alloy is composed of a mixture of two or more metals.

Alpha globulin

An alpha globulin is a type of protein present in plasma. Alpha globulins perform diverse functions in the circulation, such as transporting various substances by combining reversibly with them, transporting other proteins from within the body, and acting as substrates for the formation of other substances.

Alpha particle

An alpha particle (alpha radiation) is a positively charged particle ejected spontaneously from the decay of some radioactive elements. It is identical to the nuclei of ordinary helium atoms with two protons bound to two neutrons. Alpha particles have low penetrating power and a short range (a few centimeters in air). The most energetic alpha particle will generally fail to penetrate the dead layers of cells covering the skin and can be easily stopped by a sheet of paper. Alpha particles are hazardous when an alpha-emitting isotope is inside the body.

Alpha-1-antitrypsin

Alpha-1-antitrypsin, a glycoprotein, is a major protease inhibitor of human serum and is produced in the liver. It protects tissues from digestion and blocks the action of target enzymes by binding nearly irreversibly to their active site.

Alpha-glycerophosphate dehydrogenase (GPD)

Alpha-glycerophosphate dehydrogenase (GPD) is an enzyme, found in muscle cell cytoplasm, that is involved in the synthesis of adenosine triphosphate.

ALSA

Astronaut Life Support Assembly

ALT

Approach and Landing Test

ALT

Alanine aminotransferase (alanine transaminase, serum glutamate pyruvate transaminase)

Alternaria

Alternaria is a genus of fungi easily isolated from air that is considered to be a common laboratory contaminant and an allergen; it is occasionally pathogenic in humans.

Alternate Payload Specialist

Many Shuttle-Spacelab missions have assigned alternate payload specialists. The alternate payload specialists receive the same training as the flight payload specialists. Until one month before flight, the alternate payload specialist acts as a backup and can replace the flight payload specialist, if necessary. During the mission, the alternate payload specialists will remain on the ground (unless they replace the primary crewmember) and act as the prime communicator with the payload crew in space.

Altitude

Altitude refers to the height above sea level of a given point.

ALU

Advanced Levitation Unit

Alveolar

Alveolar refers to alveoli, air sacs of microscopic size in the lung whose function is to facilitate the exchange of oxygen and carbon dioxide from the air to blood.

Alveolar bone

In dentistry, alveolar bone (also called alveolar supporting bone) denotes the specialized bone structure, which supports the teeth.

Alveolar epithelium

The alveolar epithelium is the tissue that covers the external surface of the alveoli (air sacs of microscopic size in the lung whose function is to facilitate the exchange of oxygen and carbon dioxide from the air to blood).

Alveolar gas pressure

Alveolar gas pressure is the pressure within the alveoli, the smallest gas exchange units of the lung. Alveolar pressure determines whether air will flow into or out of the lungs. When alveolar pressure is negative, air is taken into the lungs. When alveolar pressure is positive, air is exhaled.

Alveolar ventilation (VA or V(A))

Alveolar ventilation is the passage of air into and out of the alveoli (microscopic sacs in the lungs wherein gas exchange occurs).

Amplitude Modulation

Ambient (AMB)

Ambient describes the conditions and factors in the immediate environment. For example, the ambient temperature is the local temperature. The term is also used to describe room temperature (20 degrees Celcius, 70 degrees Fahrenheit).

Amino acid

Amino acids are the building blocks of protein. Amino acids join together and form short chains (peptides) or much longer chains (polypeptides). Over 80 amino acids are known to occur naturally,with 20 found commonly in protein polypeptides.

AMM

Ames Management Manual

Amperometry

Amperometry is measurement of electrical current.

Amphibian

An amphibian is an organism, such as a frog, toad, salamander, or some types of newts, having an aquatic early stage (e.g. tadpole) and developing air-breathing lungs as an adult (e.g. frog).

Amplitude

Amplitude is a measure of the distance between the high and low points of a waveform.

Ampoule

An ampoule is a small glass vial sealed after filling (chiefly used as a container for a hypodermic injection solution).

AMR

Advanced Microwave Radiometer

AMS

Altitude Measurement Systems

AMS

Attitude Measurement Sensor

AMSU

Advanced Microwave Sounding Unit

AMU

Automatic Mass Unit

Amylase

Amylase is an enzyme that occurs in saliva and pancreatic juice and aids the digestion of starch and other polysaccharides, which it breaks down into glucose, maltose and dextrins.

Amyotrophy

Amyotrophy is muscular wasting or atrophy.

Alteration Notice

Anabolism

Anabolism is the metabolic process by which simple substances are synthesized into the complex materials of living tissue.

Anaerobe

An anaerobe is a microorganism that grows and lives in the complete or almost complete absence of oxygen.

Anaerobic

Anaerobic refers to an environment or a condition which is free of oxygen or describes a microorganism which can grow in the absence of oxygen.

Analog

An analog transmission mode is one in which data is represented by a continuous electronic signal. In an electronics system, analog, often referred to as linear, refers to measuring a continuous stream of varying voltage levels.

Analysis of variance (ANOVA)

ANOVA, or analysis of variance, is a statistical technique for investigating sets of measurements to determine the extent of experimental or chance influences on individual measures.

Androsterone

Androsterone is a steroid metabolite found in male urine and having weak androgenic potency.

Anemia

Anemia is a condition characterized by oxygen carrying deficiency caused by a low amount of red blood cells, iron deficiency, or sickle cell formation of red blood cells.

Anemostat

An anemostat is a device used to regulate the force or speed of air flow, such as by controlling the speed of an electrical fan unit.

Aneroid

Aneroid means without liquid, such as a mercury-free pressure gauge used with some sphygmomanometers.

Angiotensin

Angiotensin is a family of vasoconstrictor substances (which causes narrowing of the blood vessels), present in the blood; it is formed by the action of renin upon a globulin formed by the liver and helps regulate blood pressure.

Angular velocity

Angular velocity is rotation rate, the rate of change of angular displacement.

Animal Enclosure Module (AEM)

The Animal Enclosure Module (AEM) is designed to house up to 16 rats on the Shuttle. The animals can be monitored through the plexiglass ceiling of the module.

Anion

An anion is a negatively charged ion.

Ankle dorsiflexor

The ankle dorsiflexor (tibialis anterior) is the calf muscle which causes the foot to turn upward.

Annotation

Annotation is a critical or explanatory note; a commentary.

Anode

An anode has a negative electrical load; all positive loaded ions move towards the anode.

Anodize

By electrolytic action, anodyze is the process of coating or plating a metal (usually aluminum) with a protective material.

Anomaly

An anomaly is a deviation from the common rule; an irregularity.

Anoxia

Anoxia is an abnormal condition characterized by a lack of oxygen. Anoxia may be local or systemic and may be the result of an inadequate supply of oxygen to the respiratory system or of an inability of the blood to carry oxygen to the tissues, as in anemic anoxia, or an inability of the tissues to absorb the oxygen from the circulating blood, as in histotoxic anoxia.

ANSI

American National Standards Institute

Antagonist

An antagonist refers to a muscle in a passive state, while the opposing muscle, the agonist, is active.

Antecubital

Antecubital means pertaining to the area inside the elbow.

Antecubital fossae

The antecubital fossae is the front area where the arm bends at the elbow.

Antenna

An antenna is a metallic instrument used for transmitting and receiving electronic signals.

Anterior describes or relates to the front (or ventral) portion of the body, an organ or the limbs.

Anterior horns

Anterior horns are the inner substance of the human brain, or the gray matter. The gray matter builds two "horns"; the one pointing toward the face is called the anterior horn, the one facing towards the neck is called the posterior horn.

Anthropometric

Anthropometric means of or relating to anthropometry, the branch of anthropology concerned with comparative measurements of the human body. In space flight, for instance, the length of the spinal column is measured before and during flight to determine if the vertebrae expand in space.

Anthropometry

Anthropometry is the study of anthropometrics. Anthropometry is a branch of anthropology (the science of studying humans in all their relations), that deals with making comparative measurements of the human body. In space flight, for instance, the length of the spinal column is measured before and during flight to see if the vertebrae expand in space.

Antibiotic

An antibiotic is a substance, produced by or derived from a microorganism (especially mold), that destroys or inhibits the growth of other microorganisms. Antibiotics are used to treat infections caused by organisms that are sensitive to them, usually bacteria or fungi.

Antibody

An antibody is a special blood protein secreted by B-lymphocytes, a type of white blood cell in the immune system. Antibodies are synthesized in response to the presence of a particular antigen (foreign or potentially dangerous substances, such as bacteria and viruses). Antibodies circulate in the bloodstream and bind to the antigen rendering it harmless. White blood cells then recognize the antibodies and destroy the foreign object.

Antibody titer

An antibody titer is a measure of antibody quantity.

Anticipatory postural activity

Anticipatory postural activity describes the reflexes which prevent the body from falling to the ground in the event of an unexpected lean that sends the body out of balance. These reflexes activate the muscles before the brain can react to the change the posture. People who don’t have good anticipatory postural reflexes are more likely to fall over if they are suddenly pushed.

Antidiuretic Hormone (ADH)

Antidiuretic Hormone (ADH) is a hormone (also called vasopressin) produced and released in the posterior pituitary gland. It stimulates the kidneys to absorb water from produced urine, thus controlling the water content of the body.

Antigen

An antigen is any substance that the body regards as foreign and which therefore triggers an immune response; antigens are usually proteins associated with bacteria and viruses.

Antigenic

Antigenic means allergenic or having the properties of an antigen.

Antigravity muscle

The antigravity muscles, located in the legs, trunk and neck, function primarily to support the body against the pull of gravity; the relative degree of contraction of the individual antigravity muscles is determined by the equilibrium mechanisms, which are controlled by signals mainly from the vestibular apparatuses (sensory organs for equilibrium).

Antigravity suit (G-suit, pressure suit)

An antigravity suit or pressure suit is a garment worn by space travelers during launch and/or landing. It exerts pressure, usually by means of inflatable air bladders, on the thighs and abdomen to lessen the pooling of blood in the lower part of the body during acceleration.

Antihypotensive

Antihypotensive means of or pertaining to a substance or procedure that increases low blood pressure.

Antioxidant

An antioxidant is a substance that slows or prevents oxidation reactions, and is commonly added to prepared foods, vegetable oils and paints to prevent deterioration upon exposure to oxygen.

Antipyrine

Antipyrine is a substance used to reduce fever.

Antisera

Antisera is serum containing immunoglobulins against specific antigens.

Announcement of Opportunity

AOA

Abort-Once-Around

AOD

Assistant Operations Director

AOQL

Average Outgoing Quality Limit

Aorta

The aorta is the main artery of the body from which all others derive; it arises from the left ventricle of the heart, arches over the top of the heart and descends in front of the backbone, giving off large and small branches and finally dividing to form the right and left iliac arteries in the legs.

AOS

Acquisition of Signal (Telemetry)

Active Package

Geomagnetic Activity Index

APA

American Planning Association

APAE

Attached Payload Accommodation Equipment

Aperture

Aperature is an adjustable opening in an optical instrument that limits the amount of light passing through a lens.

Apex

An apex is the extremity of a conical or pyramidal structure.

Apical

Apical means situated at the uppermost point.

Apical dendrite

A dendrite is the slender branching process that arises from the dendrons of the nerve-cell body. A dendrite forms connections with the axons of other neurons and transmits nerve impulses. An apical dendrite is situated nearer the apex of a neuron.

APM

Antenna Pointing Mechanism

Apneic

Apneic means related to or suffering from apnea, the transient cessation of breathing or a lack of oxygen.

APP

Approved

APP

Astrophysics Payloads

APS

American Physiological Society

APS

Auxiliary Power Subsystem

APT

Advanced Propulsion Test

APT

Automatic Picture Transmission

APU

Auxiliary Power Unit

AQL

Acceptance Quality Level

Acceptance Review

Arachidonic acid

Arachidonic acid is a component of cell membranes released on their injury; forms mediators of inflammation (prostaglandins and leukotrienes).

ARC

Ames Research Center

Archival sampling

Archival sampling is the storage of samples or data by an automated sampling device.

ARCLSFEP

Ames Research Center Life Sciences Flight Experiments Program

ARCLSP

Ames Research Center Life Sciences Payload

Arcuate nucleus

The arcuate nucleus (arcuatus) is a cell group in the hypothalamus, located in the lowest part of the infundibulum adjacent to the median eminence; it is involved in neuroendocrine control through the release of releasing hormones and inhibitory hormones.

ARINC

Aeronautical Radio Incorporated

Arrhythmia

An arrhythmia is any deviation from the normal rhythm of the heart.

ARS

Atmospheric Revitalization Section

ARS

Atmospheric Revitalization Subsystem

Arterial

Arterial means of or relating to arteries. Arteries are blood vessels that carry oxygenated blood from the heart to the rest of the body with the exception of the pulmonary artery, which carries unoxygenated venous blood from the heart to the lungs.

Arterial pressure

Arterial pressure is the pressure of the blood on the walls of the arteries, dependent on the energy of the heart action, the elasticity of the walls of the arteries, and the volume and viscosity (resistance) of the blood.

Arterial-alveolar carbon dioxide difference

The arterial-alveolar carbon dioxide difference is the difference or gradient between the partial pressure of carbon dioxide in the alveolar spaces and the arterial blood. In young adults, the value is normally less than 48.

Arteriovenous

Arteriovenous means relating to both arteries and veins in general.

Arteriovenous oxygen difference

The arteriovenous oxygen difference is the arterial oxygen content minus the central venous oxygen content.

Artery

An artery is a blood vessel that carries oxygenated blood from the heart to the tissues and form part of the circulatory system. All arteries except the pulmonary artery carry oxygenated blood.

Arthropod

An arthropod is any segmented invertebrate of the phylum Arthropoda, having joined legs and including the insects, arachnids (spiders), crustaceans, and myriapods.

Artifact

An artifact is any object made or modified by man. In a scientific investigation, an artifact is a false result or effect caused by the introduction of unintended substances or structures.

ARU

Accelerometer Recording Unit

ASAHF

Advanced Small Animal Holding Facility

ASCG

Automatic Solution Crystal Growth

ASCIE

American Standards Code for Interface & Exchange

ASCII

American Standard Code for Information Interchange

Ascomycetes

Ascomycetes, has a single nucleus, and reproduces either asexually by budding or fission, or sexually through spore formation.

Ascorbic acid

Ascorbic acid, an antioxidant, is an effective reducing agent that retards oxidation, the process by which substances combine with oxygen in the air at room temperature.

ASCS

Atmosphere Storage and Control Section

ASCU

American Standard Computer Unit

ASD

Avionics Systems Division

ASE

Airborne Support Equipment

Aseptic

Aseptic means a condition in which living pathogenic organisms are absent; a state of sterility.

Aseptic technique

The aseptic technique is a manipulation of sterile instruments or culture media in such a way as to maintain sterility.

ASHRAE

American Society of Heating, Refrigeration, and Air conditioning Engineers

ASI

ASI is the abbreviation for the Italian space agency, Agenzia Spaziale Italiana, which is headquartered in Rome, Italy.

ASL

Approved Source List

ASM

Assistant Payload Science Manager

ASME

American Society of Mechanical Engineers

ASO

Advanced Solar Observatory

Aspergillus

Aspergillus is a genus of fungi that contains many black, brown, or green spored species. A few species are pathogenic to man, animals and birds.

Aspergillus species

Aspergillus species is a common genus of fungi that contains many different species. All Aspergillus species form black, brown or green spores in form of a sphere on the tip of a hypha. A few species are pathogenic for humans, other mammals and birds.

ASR

Ames Single Rack

Assay

An assay is the analysis of a substance or mixture to determine its constituents or their level. In Life Sciences, it is also the estimation of strength of a drug or substance by comparing its effects in test animals to a reference standard.

ASSESS

Airborne Science Experiment System Simulation

ASSG

Assignment

ASSMT

Assessment

ASSY

Assembly

AST

Aspartate aminotransferase (aspartate transaminase, serum glutamate oxaloacetate transaminase)

ASTM

American Society for Testing and Materials

ASTP

Apollo-Soyuz Test Project

ASVT

Applications Systems Verification Transfer

ATCS

Active Thermal Control Section

ATCS

Active Thermal Control Subsystems

ATE

Automatic Test Equipment

ATL

Advanced Technology Laboratory

ATM

Atmosphere

ATMOS

Atmospheric Trace Molecule Spectroscopy

Atmosphere

Atmosphere is a gaseous envelope surrounding a celestial body, especially that surrounding the Earth, which is retained in place by the force of gravity.

Atmospheric

Atmospheric relates to the environment or surroundings that have a physiological, physical or other influence.

Atmospheric drag

Atmospheric drag is a condition that occurs in the earth’s atmosphere which can accelerate an orbiting body.

Atmospheric physics

Atmospheric physics is the science of the physics of the atmosphere, including the components and layers of the atmosphere.

ATN

Astrophysical Teletype Network

ATO

Abort-to-Orbit

ATR

Acceptance Test Review

Atrial Natriuretic Factor (ANF)

Atrial natriuretic factor (ANF) is a hormone-like substance present in the two atrial walls of the heart (especially numerous in the right atria). ANF can cause a three to ten times increase in renal (kidney) excretion of sodium when it is fully released into the circulating blood. Consequent to the loss of sodium is a slight decrease in the extracellular fluid volume and blood volume. Although its exact mechanism of action is unclear, it is believed that the ANF plays a role in the regulation of blood volume.

Atrial natriuretic factor (ANF) receptors

Atrial natriuretic factor (ANF) receptors are a group of cells specialized to detect changes in the blood pressure. They are located within the atrial walls of the heart. Although the mechanism of the action of ANF receptors is not completely understood, it is believed that when excess blood volume stretches the atrial walls, ANF receptors located in the walls are triggered to release atrial natriuretic factor into the circulating blood. The ANF causes sodium (and water) to be excreted from the kidneys and blood volume to be reduced.

Atrial Natriuretic Peptide (ANP)

Atrial natriuretic peptide (ANP), also called atrial natriuretic factor (ANF), is a hormone-like substance present in the two atrial walls of the heart (especially numerous in the right atria). ANP can cause a three to ten times increase in renal (kidney) excretion of sodium when it is fully released into the circulating blood. Consequent to the loss of sodium is a slight decrease in the extracellular fluid volume and blood volume. Although its exact mechanism of action is unclear, it is believed that the ANP plays a role in the regulation of blood volume.

Atrial natriuretic peptide (ANP) receptors

Atrial natriuretic peptide (ANP) receptors are cell membrane bound molecules in the kidney's tubules which bind to atrial natriuretic peptide and promotes natriuresis, the excretion of sodium.

Atrioventricular dissociation

Atrioventricular dissociation is defined as the independent beating of the atria and ventricles.

Atrophy

Atrophy is the wasting away of a normally developed cell, tissue or organ. This may occur through undernourishment, disuse, aging or other mechanisms. For example, in space medicine muscle atrophy is the reduction of muscle mass resulting from disuse of the muscles.

Attenuation

Attenuation is the reduction of the disease-producing ability (virulence) of a microorganism. It can be achieved by chemical treatment, heating, drying, irradiation, by growing under adverse conditions, or by passing through another organism. Attenuated bacteria or viruses are used for some vaccines.

Attitude

Attitude is the nose up or nose down orientation of an aircraft's or spacecraft's axes relative to a reference line, plane or direction of motion.

Audible

Audible means a noise or sound which is capable of being heard.

Audiogram

An audiogram is the graphic record drawn by an audiometer, which charts the threshold of hearing at various frequencies against sound intensity in decibels.

Audiogram

An audiogram is a record of an individual's threshold of hearing at different sound frequencies.

Auditory canal

The auditory canal is the tube which extends from the opening of the ear to the tympanic membrane.

Aurelia

An aurelia is a type of jellyfish known as "moon" jellyfish. They are found in the waters of the Atlantic Ocean and the Chesapeake Bay on the eastern coast of the North American continent.

Auricle

The auricle is the outer portion of the ear. It is made out of cartilage and its function is to channel sound waves into the ear tube.

Autoflora

Autoflora refers to the microbial inhabitants of an individual.

Autogenic

Autogenic refers to something that is produced independently of external influence or aid.

Autogenic feedback training (AFT)

Autogenic feedback training is a method that can be taught to people to control motion sickness symptoms by using biofeedback techniques instead of drugs. Biofeedback provides immediate information about involuntary bodily functions to the individual, including nausea, heart rate and body temperature thus reducing motion sickness.

Autogenous

Autogenous means originating within the body.

Autoinfection

An autoinfection is reinfection of a host by microbes or parasitic organisms on or within the body that have already passed through an infective cycle, such as a succession of boils.

Autonomic function

An autonomic function is a function that is independent or self-controlling.

Autonomic nervous system (ANS)

The autonomic nervous system is the part of the nervous system that supplies stimulation to the involuntary muscles, such as the smooth and cardiac muscles, and to the glands. The autonomic nervous system is controlled principally by parts of the brain stem and the hypothalamus (a part of the brain).

Autoradiography

Autoradiography is an experimental technique in which a radioactive specimen is placed close to a photographic plate, so as to produce a record of the distribution of radioactivity in the specimen. The film is darkened by the ionizing radiation from radioactive parts of the sample. Autoradiography is used to study the distribution of particular substances in living tissues and cells. A radioactive isotope of the substance is introduced into the organism or tissue, which is killed, sectioned, and examined after enough time has elapsed for the isotope to be incorporated into the substance.

AUX

Auxiliary

Auxins

Auxins are hormone-like chemicals that induce cellular growth in plants.

Audio Visual

AVCG

Automatic Vapor Crystal Growth

AVHRR

Advanced Very High Resolution Radiometer

Avionics

Avionics is the science and technology of electronics applied to aeronautics and astronautics.

AWG

American Wire Gauge

AWS

Air Weather Service

AWS

American Welding Society

AXAF

Advanced X-ray Astronomy Facility

Axilla

The axilla is the armpit or an analogous part.

Axillary

Axillary means pertaining to the armpit.

Axisymmetrical

Axisymmetrical refers to like, or same, conditions on both sides of a body axis; a straight line about which a body or a geometric figure rotates.

Azimuth

B&W

Black & White

B-lymphocyte

B-lymphocytes (B-cells) are white blood cells, one of two major types of lymphocytes (the other being T-lymphocytes, or T-cells). B-cells develop in the bone marrow, then migrate to various parts of the body via the bloodstream. By producing and secreting immunoglobulins (antibodies) in response to antigens, B-cells are the basis of the body's humoral immune system .

B/S

Bits per Second

BAC

Boeing Aerospace Company

Bacilli

Bacilli are rod-shaped bacteria.

Background 15N

Background 15N is an isotope of nitrogen which is present in the human body in low concentrations (about 0.365%) at all times. The naturally present 15N is referred to as background 15N.

Bacteria

Bacteria refers to a group of microorganisms which consist of only a single cell that lacks a distinct nuclear membrane and has a cell wall of unique composition. Bacteria are largely responsible for decay and decomposition of organic matter.

Bactericidal

Bactericidal is causing the death of bacteria.

Bacteriological

Bacteriological means relating to bacteria.

Bacteriology

Bacteriology is the scientific study of bacteria.

Bacteriophage

A bacteriophage is a virus that infects a bacterium or prokaryotes.

Bacteriorhodopsin

Bacteriorhodopsin is a carotenoid (naturally occurring pigment found mostly in plants) analogous to rhodopsin, the pigment of the animal eye, which functions in vision. Bacteriorhodopsin is able to absorb light and generate a proton gradient across the membrane of halobacterium (a microbe), leading to ATP synthesis without the involvement of chlorophyll.

Bacteriotherapy

Bacteriotherapy uses bacteria in the treatment of or control of disease; particularly intestinal diseases.

Bacteroid

A bacteroid is a microbe that resembles bacteria in shape or action.

Ballistic

Ballistic refers to the science of projectiles. Before the development of spacecraft capable of orbiting the Earth, ballistic missiles were launched. These missiles reached an environment of microgravity but followed a ballistic trajectory, still influenced by the Earth's gravity and atmospheric friction.

Barcode

A barcode is a label consisting of coded lines and spaces of different thicknesses (and sometimes numerals). It can be scanned by a barcode reader to provide information about the item on which it is found.

Barium

Barium is a metallic, alkaline, divalent earth element (atomic number 56, atomic weight 137.327). Salts of this element are often used in diagnostic tests.

Barophysiology

Barophysiology is the study of the effects of air pressure on the body's physiology.

Baroreceptor

A baroreceptor is a collection of sensory nerve endings specialized to monitor changes in blood pressure. The main receptors lie in the carotid sinuses and the aortic arch. Others are found in the walls of other large arteries and veins and some within the walls of the heart. Impulses from the receptors reach centers in the medulla, a part of the brain; from there autonomic activity is directed so that the heart rate and resistance of the peripheral blood vessels can be adjusted appropriately to maintain a stable blood pressure.

Baroreflex

A baroreflex is a reflex triggered by the stimulation of a baroreceptor (a collection of sensory nerve endings in the wall of the heart auricles, vena cava, aortic arch and carotid sinuses that are specialized to monitor changes in blood pressure). The baroreflex acts to increase or decrease the blood pressure to maintain a stable blood pressure within the body.

Barotitis media

Barotitis media (or aerotitis media) is inflammation or bleeding in the middle ear caused by difference between the air pressure in the middle ear at of the atmosphere, as occurs in sudden changes in altitude. Symptoms are pain, tinnitus, diminished hearing, and vertigo.

Baseline

A baseline is a measurement that serves as a basis to which all following measurements are compared. An example: before exercise, your heart rate is measured. During exercise, your increased heart rate is measured and compared to your resting baseline measurement taken before exercise started.

Basophil

Basophils are white blood cells that stain readily with basic dyes. Their nucleus is surrounded by granular cytoplasm. Basophils are produced continually by stem cells in the bone marrow. The function of basophils is not fully understood, but it is known that they are capable of ingesting foreign particles and produce heparin and histamine (chemicals which induce inflammation).

BAT

Battery

Batch crystallization

Batch crystallization is a technique used for growing protein crystals by adding a precipitating solution directly to a protein solution and mixing them together. Once the precipitating solution is added, the mother liquor becomes supersaturated causing the proteins to solidify and crystallize.

BATSW

Battery Switch

BAUD

A Data Transfer rate of one signaling unit per second

BBN

Bolt Beranek and Newman, Inc.

BCD

Baseline Configuration Document

Bed rest

Bed rest studies are tests performed where the subject is confined to bed to simulate stays in space by reducing gravitational pull to the antigravity muscles and bones.

Behavior and performance

Behavior and performance research conducted by NASA is designed to develop a knowledge of how space mission design and events, and spacecraft environment, affect the behavior and performance of crews. Countermeasures developed from this research will enhance the ability of humans in space and on the ground to cope with issues such as team problem-solving, decision-making and communication, team structure and expertise, cultural variability, uncertainty, stressors like isolation and confinement, and time pressure.

Benzene

Benzene is a highly toxic hydrocarbon used as the basic structure in the aromatic compounds of all chemistry and as a sorbent.

Benzoic acid

Benzoic acid is an organic aromatic acid commonly used as a preservative to inhibit the growth of bacteria and sometimes used as an antifungal agent.

BEST

Bioexperiment Support and Transfer

Beta globulin

Globulins are a group of global proteins that are generally insoluble in water and present in blood, eggs, milk, and as a reserve protein in seeds. Blood serum globulins comprise four types: alpha-1, alpha-2, beta-globulins which serve as carrier proteins, and gamma-globulins which include the immunoglobulins responsible for immune responses.

Beta ray

A beta ray is a stream of high speed electrons, or beta particles, emitted from a radioactive nucleus in beta decay.

Beta-cloth

Beta-cloth is a glass fiber material characterized by extremely small diameter fibers, which provides a non-flammable, high temperature flame barrier.

Beta-hemolytic

Beta-hemolytic refers to complete or true hemolysis, observed in blood agar cultures of various bacteria, especially hemolytic streptococci; virtually all of the erythrocytes are destroyed in a wide circular zone around the colony, thereby resulting in a clear “halo” of transparent agar; the zone of hemolysis is frequently much wider than the diameter of the colony.

BGE

Biological Growth Experiment

Biceps femoris

The biceps femoris is a muscle of the posterior thigh, which acts to flex the knee and rotate the tibia laterally.

Bifurcation

A bifurcation is a forking or division into two branches.

Bigeminy

Bigeminy is a condition in which alternate ectopic beats of the heart are felt as a double pulse beat.

Bilateral

Bilateral means appearing or occurring on two sides.

Bilirubin

Bilirubin is one bile pigment (the other is named biliverdin), which is produced by the breakdown of the blood pigment hemoglobin. Bilirubin has a yellow-orange color. Bile itself is a greenish-yellow alkaline fluid produced by the liver and stored in the gall-bladder. It assists the digestion and absorption of fats.

Binary

Binary describes something made of two things or two parts. In chemistry, this might mean a substance made of two elements or two compounds.

Binding

Binding refers to the combining or uniting of molecules by employing reactive groups within the molecule or by using a binding chemical. Binding is especially associated with a chemical bond that is easily broken.

Bioassay

Bioassay is a technique used to determine the potency or concentration of a substance (such as a drug) by comparing its effect on a test organism with that of a standard preparation.

Bioavailability

Bioavailability is the degree to which an agent, such as a drug or nutrient, becomes available at the site of activity in the body.

Biochemical

Biochemical refers to the chemical reactions that occur within a living organism, such as the breakdown or manufacture of biological molecules by enzymes.

Biochemistry

Biochemistry is the study of the chemistry of living organisms, especially the structure and function of their chemical components (principally proteins, carbohydrates, lipids, and nucleic acids).

Biocompatibility

Biocompatibility is the ability of biologic materials to exist or perform in harmonious combination.

Biofeedback

Biofeedback is a training technique that enables an individual to gain some element of voluntary control over autonomic (involuntary) body functions, such as heart rate. This is accomplished by providing immediate information about these bodily functions to the individual. Biofeedback is currently used as an experimental treatment for disturbances of bodily regulation, such as hypertension, and is most effective in the treatment of high blood pressure, migraines, and epilepsy.

Bioinstrumentation

Bioinstrumentation is the use of a sensor or other device (bioinstrument) to record and transmit physiologic data to a receiving and monitoring station. The device is attached to or embedded in the subject’s body.

Biologically active

A biologically active molecule has a unique structure that allows it to participate in biochemical reactions.

Biomass

Biomass is the total mass of all the organisms of a given type and/or in a given area. It is normally measured in terms of grams of dry mass per square meter.

Biomechanics

Biomechanics is the application of the principles of mechanics to living systems, particularly those living systems that have coordinated movements.

Biopsy

Biopsy is the process of removing a small section of tissue from a potentially diseased organ or tissue in a living organism. The biopsy sample can undergo more detailed diagnostic examinations, such as microscopic analysis.

Biorack

Biorack is the name for a multipurpose facility designed by the European Space Agency (ESA) to study the effects of microgravity and cosmic radiation on small life forms such as cells, tissue samples, small organisms and plants. Biorack contains three incubators, which operate at different temperatures, a cooler, a freezer and two 1-G reference centrifuges.

Bioreactor

Bioregeneration

Bioregeneration is the renewing or restoring of life-supporting resources using biological processes; usually describing processes in a closed system.

Bioregenerative

Bioregenerative systems renew or restore life-supporting resources using biological processes.

Biorespirator

A biorespirator is a device worn over the nose and mouth that limits the inhalation of toxic materials or the contamination of one's surroundings. They range from disposable dust masks to self-contained breathing apparatus.

Biorhythms

Biorhythms are roughly periodic changes in the behavior or physiology of an organism that is maintained and generated by a biological clock. Well known examples are the sleep cycle, annual rhythms, or menstrual cycles.

Biosensor

A biosensor is a device that translates biological variables such as electric potentials, movement and chemical concentrations into electrical signals.

Biosphere

The biosphere is the whole region of the Earth's surface, including the sea and the air, that is inhabited by living organisms.

Biostack

The Biostack is made up of cylindrical containers with layers of dormant biological objects, such as seeds, interleaved with sheets of light or radiation particle detectors. The biological objects identify the biological damage of light or radiation, while the detector sheets map the location of the hit and the size of light particles.

Biotechnology

Biotechnology refers to the industry that uses biological processes to make a product, such as a drug. An example is the use of yeast in the fermentation of beer.

BIT

Built-in Test

BIT

Least possible quantity of information in a digital system

BITE

Built-in Test Equipment

Blastoid

A blastoid is a cell that has undergone blastogenesis which is the transformation of a functionally dormant cell to an active cell. A blastoid cell is characterized by expansion of the cytoplasm and enlargement of the cell nucleus.

Blood pressure

Blood pressure is the force exerted by blood on the walls of the arteries. This pressure is greatest during the contraction of the ventricles of the heart (systolic pressure), which forces blood into the arterial system. Pressure falls to its lowest level when the heart is filling with blood (diastolic pressure).

Blood Urea Nitrogen (BUN)

Blood Urea Nitrogen (BUN) is nitrogen in the blood in the form of urea. The urea is formed in the liver as the end product of protein metabolism and is deposited in the blood to be excreted through the kidneys. The BUN, determined by blood test, is directly related to the metabolic function of the liver and the excretory function of the kidney.

Blood volume

Blood volume is the total amount of circulating blood in the body, normally about 5.5 liters.

BMCP

Biomedical Computer Programs, UCLA

BMMD

Body Mass Measurement Device

BMRP

Biomedical Research Project

Ballistic Number

Body axis

The body axis is an imaginary longitudinal line through the vertical center of the body (head to feet) or one of its parts, or a line about which the body or a part rotates. Development of the body in vertebrates and most other animals occurs in a nearly symmetrical fashion around the body axis.

BOL

Beginning of Life

Bomb calorimetry

Bomb calorimetry is a method used to determine the potential energy of organic substances, including those in foods by means of an instrument called a bomb calorimeter. The bomb calorimeter consists of a hollow steel container, lined with platinum and filled with pure oxygen, into which a weighed quantity of food is placed and ignited with an electric fuse. The heat produced is absorbed by water surrounding the bomb and, from the rise in temperature, the calories liberated are calculated.

Bone and calcium physiology

Bone physiology, or bone and calcium physiology as it's also known, is the study of the structure, processes and function of bone and its major constituent, calcium.

Bone demineralization

Bone demineralization is the loss of minerals, including calcium and phosphorous, from the bone.

Bone density

Bone density is the mass per unit volume of bone under specified conditions of pressure and temperature.

Bone formation

Bone formation is the process by which new bone is created from cells known as osteoblasts or bone forming cells. Bone formation adds minerals such as calcium to bone matrix, making it stronger.

Bone loss

Bone loss is the weakening and destruction of bone, particularly through demineralization. Demineralization is the loss of minerals, such as calcium from the bones or other mineralized structures of the body.

Bone marrow

Bone marrow is the soft tissue contained within the internal cavities of the bones. Bone marrow is a site of blood cell formation, especially in young animals and humans.

Bone matrix

Bone comprises a matrix of collagen fibers (30%) impregnated with bone salts (70%), mostly calcium phosphate and carbonate.

Bone metabolism

Bone metabolism describes the process by which bone is destroyed and rebuilt at any given time to keep up its strength.

Bone mineral mass

Bone mineral mass is the amount of mineral in a bone.

Bone mineralization

Bone mineralization is the process of adding minerals such as calcium and phosphorous to the bone.

Bone mineralization rate

Bone mineralization rate is the speed at which minerals such as calcium and phosphorous are added to the bone.

Bone physiology

Bone physiology, or bone and calcium physiology as it's also known, is the study of the structure, processes and function of bone and its major constituent, calcium.

Bone remodeling site

Bone remodeling sites are specific sites located along most of the outer surface of bone where the synthesis and resorption of bone takes place. The sites are regulated by specialized cells which control the synthesis or resorption process. Long bones also have remodeling sites along the inner surface of the bone shaft, adjacent to the bone marrow cavity.

Bone resorption

Bone resorption is the absorption of the bone by large multi-nucleated cells called osteoclasts; resorption occurs normally in very small amounts, but can claim large quantities of bone in circumstances where normal physical weight-bearing stress is absent, such as bed rest or exposure to microgravity. The loss of calcium is associated with resorption of bone.

BOP

Baseline Operation Plan

Boric acid

Boric Acid is a white, odorless powder or crystalline substance used as a buffer.

Boyden chamber

A Boyden chamber is a simple chamber used to test for chemotaxis, especially of leukocytes. Consists of two compartments separated by a millipore filter (3 - 8 micrometer pore size); chemotactic factor is placed in one compartment and the gradient develops across the thickness of the filter (ca 150 micrometer). Cell movement into the filter is measured after an incubation period less than the time taken for the gradient to decay. See also checkerboard assay.

BPI

Bits per Inch

BPMS

Blood Pressure Measurement System

BPS

Bits per Second

BRAC

Biotelemetry RAHF (Research Animal Housing Facility) Animal Cage

Brachialis

The brachialis is a muscle that is situated at the front of the upper arm and contracts to flex (lift-up) the forearm; it works against the triceps brachii (lowering the forearm).

Bradycardia

Bradycardia is relatively slow heart action, usually at a rate of less than 60 beats per minute.

Bremsstrahlung

Gamma particles are produced in abundance when high-energy electrons impinge on any material. The electrons are subject to violent collisions, and the photons that result from these collisions are formally called bremsstrahlung radiation, (bremsstrahlung is German for decelerated-radiation). A gamma particle is known by other names, such as X-ray, photons and light. Low-energy forms are called ultraviolet rays, infrared rays, even radio waves. A photon is one of the fundamental particles in nature and it plays an important role in being involved in the interactions between electrons. Photons are the most familiar particles in everyday existence. The light we see, the radiant heat we feel, microwaves to cook with, are all photons of different energies. A gamma is simply a name given to the most energetic of these particles.

BRFS

Biotelemetry System Radio Frequency Simulator

Brittle

Brittle means easily broken, cracked or snapped.

Bronchitis

Bronchitis is an acute or chronic inflammation of mucous membranes of the tracheobronchial tree.

Bronchoalveolar lavage

Bronchoalveolar lavage (BAL) is a procedure that uses the bronchoscope to send water (sterile saline solution) into the bronchioles and air sacs. The bronchoscope then sucks the water back out. Doctors can examine cells and mucus removed this way to diagnose diseases. Sometimes BAL is used to clear extra mucus or other secretions from the lungs.

BRP

Biological Research Project

BRS

Body Restraint System

BSMRC

Biological Specimen Management and Review Committee

BSP

Biospecimen Sharing Program

BTS

Biotelemetry System (a subset or prototype of ABS for SL-3)

BTU

British Thermal Unit

Buccal cavity

The buccal cavity is the mouth.

Buffer

A buffer is a system capable of resisting changes in pH, consisting of a conjugate acid-base pair in which the ratio of proton acceptor to proton donor is near unity.

Buffy coat

Buffy coat is the thin yellow-white layer of leukocytes on top of the mass of red cells when whole blood is centrifuged.

Bulk solution

A bulk solution is a solution that contains protein molecules used to form the protein crystals.

Bungee cord

A bungee cord is an elasticized cord.

Buoyancy

Buoyancy is the capacity to float in a liquid medium.

BYTE

Eight Bits

Celsius

Centrifuge Degrees

Continuous Bit Stream

Combustible

C&D

Control and Display

C&T

Communications and Tracking

C&W

Caution and Warning

C-peptide

C-peptide, also known as connecting peptide, is a peptide produced (along with insulin) by hydrolysis of the insulin precursor molecule. A certain proportion of the C-peptide is excreted in the urine, and the urinary C-peptide excretion rate is used as a marker for insulin secretion.

C-reactive protein

Serum C-reactive protein concentrations closely follow a person's response to inflammation, theoretically providing a barometer for many disease processes; it is present in acutely ill patients and disappears as the patients recover. C-reactive protein has been detected in bacterial, viral and other infections, as well as in noninfectious diseases. Studies suggest that C-reactive protein activates neutrophils and facilitates cell-mediated cytotoxic reactions against cells infected with microbes and stimulates monocyte-macrophage tumoricidal activity.

C/D

Countdown

C/O

Carry On

C/O

Check Out

Cost Avoidance

CAD

Computer-Aided Design

CADSI

Communications and Data Systems Integration

CAE

Computer-Aided Engineering

Calcified

Calcified refers to the occurrence of the process of calcification, which is the deposition of calcium salts in tissue. This occurs as part of the normal process of bone formation, called ossification.

Calciotropic

Calciotropic refers to the group of hormones responsible for bone growth and remodeling.

Calcitonin

Calcitonin (also called thyrocalcitonin or CT) is a hormone, produced by certain cells in the thyroid gland, that lowers the levels of calcium and phosphate in the blood. Calcitonin is believed to inhibit the resorption of bone.

Calcium (Ca)

Calcium is an element essential for the normal development and functioning of the body, typically present in the blood at a concentration of about 10mg/100ml. Calcium is an important constituent of bones and teeth and is essential for many metabolic processes, including nerve function, muscle contraction and blood clotting.

Calcium alginate

Calcium alginate is a topical hemostatic.

Calcium balance

Calcium balance is a measure of the intake and output of calcium from the body. The amount of free calcium in the body is measured by blood calcium levels. Higher than normal levels of calcium in the blood (hypercalcemia) may be an indication of many things, including an abnormal loss of bone calcium, caused by bone demineralization.

Calcium deposition

Calcium deposition refers to the process by which calcium and phosphate are added to organic bone material (osteoid). The addition of calcium and phosphate is responsible for the final hardening stage during bone formation or remodeling.

Calcium homeostatic mechanism

The calcium homeostatic mechanism refers to a group of physiologic processes which act jointly to maintain normal blood calcium levels by regulating intestinal calcium absorption, calcium deposition and resorption from bone, and calcium excretion.

Calcium lactate

Calcium lactate is a salt of lactic acid commonly used as a calcium replenisher.

Calcium metabolism

Calcium metabolism is the distribution and utilization of calcium throughout the body, such as for bone formation and muscle contraction.

Calcium oxalate

Calcium oxalate is a chemical compound usually found as sediment in the urine and in urinary calculi. It can, if found in large quantities in the urine, indicate a higher than normal loss of calcium from the body, and thus indicate potential disease or abnormalities.

Calcium phosphate

Calcium phosphate is formed when free calcium and phosphate interact. In the human body, this interaction can happen when both minerals are excreted through the urinary tract, due to saturation of both minerals in the body, leading to the build-up of calculi and/or renal stones. Calcium phosphate is also referred to as calcium rock and its chemical formula is Ca3(PO4)2.

Calcium/bone homeostatic system

Calcium/bone homeostatic system is another term for the process of calcium balance, which is a measure of the intake and output of calcium from the body as measured in blood. Higher than normal levels of calcium in the blood (hypercalcemia) may be an indication of many things, including an abnormal loss of bone density. Demineralization is the term used to describe the breakdown of bone minerals, including calcium, during conditions of bed rest or disuse of bones, such as in weightlessness, and in medical conditions like osteoporosis.

Calcium/bone system

Calculi (plural of calculus)

Calculi are abnormal, hard structures formed in an animal's body. In this database, "calculi" or "calculus" usually refers to urinary calculi, which are calculi formed in the urinary tract. Renal calculi are kidney stones.

CALIB

Calibration

Calibrate

To calibrate means to check or adjust the graduations of a quantitative measuring instrument. To cross-calibrate is to extend the check or adjustment of graduations across one or more instruments.

Calibration curve

A calibration curve is a curve generated to standardize laboratory procedures.

Calisthenics

Calisthenics are gymnastic exercises designed to develop muscle tone and physical well being.

Caloric irrigation

Caloric irrigation is a procedure in which the ears are alternately irrigated with warm or cold water. Warm irrigation produces rotary nystagmus toward the irrigated ear. Cold irrigation produces a rotary nystagmus away from the irrigated ear. If the ear is normal, all irrigations will produce nystagmus that is appoximately equal in intensity.

Caloric nystagmus

Caloric nystagmus is a reflexive rhythmical oscillation (jerky motion) of the eyeballs. The caloric nystagmus effect is stimulated by dropping hot or cold water into the ear.

Caloric test

A caloric test is designed to produce and measure a condition known as caloric nystagmus. Caloric nystagmus is a jerky, involuntary, rapid, rhythmic movement of the eyeball, which may be horizontal, vertical, rotatory or mixed. Caloric nystagmus is induced by injecting warm or cold water into the labyrinth of the inner ear.

Calorie

A calorie is a unit used to denote the energy expenditure of an organism and the fuel or energy value of food.

Calorimetry

Calorimetry is the measurement, usually by use of a calorimeter or other instrument, of heat given off or absorbed.

Calvaria

The calvaria (cranium cerebrale) is the roof of the skull, i.e., the upper dome-like portion of the skull.

CAM

Commercial Aviation and Military

CAM

Computer-Aided Manufacturing

Canadian Space Agency (CSA)

The Canadian Space Agency (CSA) acts as a focal point for Canada’s space activities. The agency encourages and supports research, technology, and operations throughout Canada. CSA is headquartered in Montreal, Quebec, Canada.

Candida albicans

Candida albicans is a species of yeast-like fungi normally a part of human gastrointestinal flora, but can become pathogenic when there is a disturbance in the balance of flora or in debilitation of the host (also called thrush fungus).

Canthus

The outer canthus of the eye refers to the small area of skin closest to the side of the head, where the upper eyelid meets the lower eyelid.

CAP

Crew Activity Plan

CAPCOM

Capsule Communicator

Capillary

A capillary is the narrowest type of blood vessel in the circulatory system. The walls are only one cell layer thick enabling oxygen and nutrients to pass through them into the surrounding tissues. Capillaries also transport waste material, such as urea and carbon dioxide, to venules for excretion.

Capillary density

A high capillary density means that many small capillaries are present in the tissue, allowing a high supply or oxygen and nutrients.

Capillary endothelium

The capillary endothelium is the single layer of cells that build the walls of the capillaries. Capillaries are microscopic blood vessels which enable the exchange of nutrients and wastes between the blood and the tissues.

Capillary tube

A capillary tube is a very thin tube (approximately 1.1 or 0.75 mm in diameter).

Capstan

Capstan is a vertical cleated drum or cylinder, revolving on an upright spindle, and surmounted by a drumhead with sockets for bars or levers. It is much used, especially on shipboard, for moving or raising heavy weights or exerting great power by traction upon a rope or cable, passing around the drum.

Carbohydrate

A carbohydrate is any of various neutral compounds of carbon, hydrogen, and oxygen (as sugars, starches, and celluloses) most of which are formed by green plants and which constitute a major class of animal foods.

Carbon (C)

A nonmetallic tetravalent element (atomic number 6, atomic weight 12.001). Carbon is the major bioelement.

Carbon dioxide (CO₂)

Carbon dioxide is a colorless and odorless gas formed in the tissues during metabolism and carried in the blood to the lungs, where it is exhaled (an increase in the concentration of this gas in the blood stimulates respiration). Carbon dioxide occurs in small amounts in the atmosphere (0.04% volume); it is used by plants in the process of photosynthesis. Its chemical symbol is CO₂.

Carbon dioxide output

Carbon dioxide output is the full volume of carbon dioxide exhaled.

Carbon monoxide (CO)

Carbon monoxide is a colorless, odorless and poisonous gas formed by the incomplete combustion of carbon (like in car exhaust). Its toxic action is due to its strong ability to bond with red blood cells and thus block the binding site for oxygen, thus reducing the ability for the blood to transport oxygen in the body. Its chemical symbol is CO.

Carbon monoxide diffusing capacity (DLCO)

Carbon monoxide diffusing capacity (DLCO) measures the transfer of a diffusion-limited gas (carbon monoxide, CO) across the alveolocapillary membrane. CO combines with hemoglobin approximately 210 times more readily than oxygen. In the presence of normal amounts of hemoglobin and normal ventilatory function, the primary limiting factor of diffusion of CO is the status of the alveolocapillary membrane. This is significant because DLCO is usually decreased in emphysema because of the decrease in the total lung surface area, loss of capillary bed, increased distance from terminal bronchiole to alveolocapillary membrane and the mismatching of ventilation to blood flow.

Carbon monoxide rebreathing method

Carbon monoxide rebreathing is a safe and reliable method used to determine blood volume. During the procedure, a subject lies in the supine position with a catheter inserted in an antecubital vein. After approximately 20 minutes, a baseline blood sample is collected and analyzed for hematocrit, total hemoglobin, and carboxyhemoglobin. After the baseline blood sample has been collected, the subject breathes pure oxygen in a closed system for approximately one minute. After the one minute, 60 milliliters of carbon monoxide is injected into the rebreathing system and rebreathed for 10 minutes. At the end of the rebreathing period, a second blood sample is drawn.

Carbonaceous

Carbonaceous means producing, containing or pertaining to carbon, a naturally abundant nonmetallic element that occurs in many inorganic and in all organic compounds.

Carcinogen

A carcinogen is any cancer-producing substance.

Carcinoma

A carcinoma is cancerous tissue or cell of epithelial origin.

Cardiac

Cardiac means of, relating to, situated near, or acting on the heart.

Cardiac arrhythmia

A cardiac arrhythmia is any deviation from the normal rhythm of the heart.

Cardiac cycle

The cardiac cycle is the period from the end of one heart contraction to the end of the next.

Cardiac dysrhythmia

Cardiac dysrhythmia is abnormal heart rhythm.

Cardiac filling

Cardiac filling refers to the process by which the heart fills with blood.

Cardiac function

Cardiac function is the hemodynamic and electrophysiological action of the heart, which can be assessed by measuring end diastolic volume, end systolic volume, stroke volume, cardiac output, ejection fraction, and wall thickening.

Cardiac output (CO)

Cardiac output (CO) is the amount of blood pumped by the heart in a unit period of time. The overall blood flow in the circulation of an adult person at rest is about 5000 milliliters per minute.

Cardiac Output Heart Rate (COHR)

Cardiac Output Heart Rate (COHR) denotes heart rate during cardiac output.

Cardioacceleration

Cardioacceleration is a term used to describe a condition that increases the heart beat of a living organism.

Cardiogenic Oscillations (CGO)

Cardiogenic Oscillations (CGO) are respiratory oscillations of cardiac origin, i.e., originating from the heart, which are usually apparent on respiratory recordings made by a spirometer (a device which records the movement of air into and out of the lungs).

Cardiologist

A cardiologist is a physician who specializes in the heart and cardiovascular system.

Cardiopulmonary

Cardiopulmonary means of or relating to both the heart and lungs.

Cardiorespiratory

Cardiorespiratory means relating to the heart and lung system.

Cardiotachometer

A cardiotachometer is an instrument that continuously monitors and measures the heart beat.

Cardiothoracic (C/T) ratio

The cardiothoracic (C/T) ratio is the ratio of the transverse diameter of the heart to the internal diameter of the chest at its widest point just above the level of the dome of the diaphragm.

Cardiovascular

Cardiovascular means of or relating to the heart and blood vessels.

Cardiovascular deconditioning

Cardiovascular deconditioning is a decrease in fitness of the cardiovascular system (system of heart and blood vessels that supplies blood throughout the body) and can result from a stay in microgravity. Some deconditioning changes occur within the first few hours of weightlessness, while other changes occur over several days or weeks. In general, changes resulting from adaptation to microgravity include a headward shift of body fluids, consequent loss of water (and lower blood volume) from the body and a slight weakening of the heart muscle due to a decreased work load in space.

Cardiovascular physiology

Cardiovascular physiology is the study of the function of the heart and the blood vessels.

Cardiovascular system

The cardiovascular system is the system of the heart and blood vessels.

Caries

Caries is the molecular decay or death of a bone, in which it becomes softened, discoloured and porous. In dentistry, caries is another name for cavities caused by tooth decay.

Cariogenic

Cariogenic means to produce caries.

Carotid artery

The carotid artery is the main artery that supplies blood to the head. A pair of carotid arteries arise from the aorta and run up the neck; they branch into an external and an internal artery, which supply the head with oxygenated blood.

Carotid sinus

The carotid sinus is a slight dilation of the common carotid artery at its bifurcation into external and internal carotids. The carotid sinus contains baroreceptors, nerve endings specialized to monitor changes in blood pressure.

Cartilage

Cartilage is a dense connective tissue composed of a matrix and is capable of withstanding considerable pressure. Cartilage is commonly found in adults in the nose, ear, intervertebral disks and tendons.

CAS#

Chemical Abstract Standard Number

Casein

Casein is a group of proteins isolated from milk.

Catabolism

Catabolism is the chemical decomposition of complex substances by the body to form simpler ones, accompanied by the release of energy. The substances broken down include nutrients in food (carbohydrates, proteins, etc.), as well as the body's storage products (such as glycogen).

Catalase

Catalase is a hemoprotein that catalyzes the decomposition of hydrogen peroxide to water and oxygen.

Catalyst

A catalyst is substance which increases the rate of a chemical reaction without itself being used up in the reaction.

Cataract

A cataract is an abnormal progressive condition of the lens of the eye, characterized by the loss of transparency. A gray-white opacity can be seen within the lens, behind the pupil.

Catecholamines

Catecholamines are a group of chemical substances, including epinephrine, norepinephrine and dopamine, having various roles (mainly as neurotransmitters) in the functioning of the sympathetic and central nervous systems. Chemically, all contain a benzene ring with adjacent hydroxyl groups and an amine group on a side chain.

Catheter

A catheter is a thin plastic tube that can be inserted into the body to make measurements or add or remove fluid. For example, a catheter can be introduced into an artery and moved to a location in the heart to measure pressure changes.

Cathode

A cathode has a positive electrical charge; all negative ions move towards the cathode.

Cation

A cation is a positively charged ion.

Caudate nucleus

The caudate nucleus is an area of the brain which is a part of several important neural pathways. It helps to control intentional body movements that are normally performed subconsciously, such as the positioning of large body parts (such as the arm) so that other, smaller body parts can be manipulated (such as the fingers and hand).

Control Board

CCA

Contract Change Authorization

CCAFS

Cape Canaveral Air Force Station

CCB

Configuration Control Board

CCBD

Configuration Control Board Directive

CCBO

Configuration Control Board Operations

CCD

Charge Coupled Device

CCF

Control Computing Facility

CCITT

Consultative Committee for International Telephone and Telegraph

CCN

Change Control Notice

CCP

Configuration Change Panel

CCR

Change Control Request

CCS

Central Control Section

CCS

Console Communications System

CCSDS

Consultative Committee for Space Data Systems

CCT

Computer-Compatible Tape

CCTV

Closed Circuit Television

CCW

Counter Clockwise

CCZ

Command and Control Zone

Concept Document

CDC

Count Down Clock

CDM

Communication Data Manager

CDMS

Command and Data Management Subsystem

CDMS

Command and Data Management System

CDR

Critical Design Review

CDSC

Communications Distribution and Switching Center

CDT

Configuration Data Table

CDTR

Cassette Data Tape Recorder

Change Evaluation

CE&IS

Combined Elements and Integrated Systems

Cecum

The cecum is the beginning of the large intestine, a blind pouch into which the ileum (the last part of the small intestine) opens.

CEDC

Cyclic-Error Detection Code

CEI

Configuration End Item

CEI

Contract End Item

Cell

A cell is the basic structural and functional unit of all organisms; the smallest structure capable of performing all the activities vital to life.

Cell and molecular biology

Researchers in gravitational cell and molecular biology study the effects of gravity and its absence on biological processes at the cellular, organelle, and molecular levels.

Cell biology

Cell biology is the study of cellular form and function on a microscopic and molecular level.

Cell culture

Cell culture is the maintenance or growth of cells after removal from the body, commonly on a glass surface immersed in nutrient fluid.

Cell differentiation

Cell differentiation, in embryology, is the process in embryonic development during which unspecialized cells become specialized for particular functions. Differentiation, in oncology, is the degree of similarity or difference of tumor cells to the structure of the organ from which the tumor arose.

Cell-mediated immunity

Cell-mediated immunity is that component of immunity in which specially sensitized lymphocytes (T-cells) attach to antigens to destroy them.

Cellular

Cellular means of, relating to, or consisting of cells.

Cellulolytic

Cellulolytic means having the capacity to hydrolyze cellulose.

Cellulose

Cellulose is a polysaccharide carbohydrate composed of linked glucose units. It is the main consitutent of plant cell walls and is the most common organic compound on Earth.

Cellulose acetate electrophoresis

Cellulose acetate electrophoresis is a process by which charged particles are separated in a gel by differences in their charge density. The particles are then detected by staining on a cellulose acetate sheet for quantification of particle size.

CELSS

Controlled Environment Life Support System

Center of mass

The center of mass of a body is the three-dimensional midpoint of its mass, the point at which the mass can be considered to be concentrated.

Central Nervous System (CNS)

The Central Nervous System (CNS) consists of the brain and spinal cord. The CNS is responsible for the integration of all nervous activities.

Central Venous Pressure (CVP)

Central venous pressure (CVP) is the pressure in the right atrium of the heart (normally 0 mmHg). CVP is regulated by the ability of the heart to pump blood out of the right atrium and the tendency for blood to flow from the peripheral vessels back into the heart.

Centrifugal

Centrifugal means acting by centrifugal force, the force produced by rotation about a central point, which causes rotated objects or parts of them to move outward, away from the center.

Centrifuge

A centrifuge is a device that rotates at various speeds about a fixed, central point; it can separate liquids from solids or liquids of different densities by way of the centrifugal force resulting from its rotation.

Centripetal acceleration

Centripetal acceleration occurs during uniform circular motion. It is the average acceleration, proportional to the change in velocity, directed towards the center of the circle. Centripetal force, which causes centripetal acceleration, acts on the body in motion and is directed towards the center of the circle.

Centromere banding (C-banding)

Centromere banding (C-banding) is a selective chromosome banding used in human cytogenetics, employing Giemsa after most of the DNA is denatured.

CER

Cost Estimating Relationship

Cerebellar

Cerebellar refers to cerebellum, the largest part of the hindbrain. The cerebellum is concerned with coordination of muscle movements and is essential for maintenance of muscle tone and balance.

Cerebellum

The cerebellum is the largest part of the hindbrain and is located behind the pons and the medulla oblongata. The cerebellum is concerned with coordination of muscle movements. It is also essential for maintenance of muscle tone, balance, and the synchronization of activity in groups of muscles under voluntary control, converting muscular contractions into smooth coordinated movements.

Cerebral

The term cerebral refers to the portion of the brain that comprises mainly the central hemisphere (cerebral cortex and basal ganglia).

Cerebral blood flow

Cerebral blood flow is the amount of blood flowing through the cerebrum (the brain).

Cerebral cortex

The cerebral cortex is the surface layer of gray matter of the cerebrum that functions chiefly in coordination of sensory and motor information.

Cerenkov radiation

Cerenkov radiation is visible light produced by charged particles (as electrons) traversing a transparent medium at a speed greater than that of light in the same medium; it is also called Cerenkov light. The light observed is frequently attributed to a shock wave phenomenon and has been thought of as an optical analog of the sonic boom. High-energy nuclei with a charge greater than or equal to 6 are capable of producing Cerenkov light.

CERMA

Centre de Recherches de Medicine Aeronautique

Ceruloplasmin

Ceruloplasmin is a copper-containing alpha globulin of blood plasma. It is believed to play a part in red blood cell production and oxygen (O2) reduction.

Cervical

Cervical means of or relating to the neck or cervix of the womb.

Cervical vertebrae

Cervical vertebrae are the seven bones making up the neck region of the backbone.

CEVP

Countermeasure Evaluation Validation Project

Cryogenic Freezer

CFA

Centrifugal Fast Analyzer

CFE

Contractor Furnished Equipment

CFM

Cubic Feet per Minute

CFR

Code of Federal Regulations

Center of Gravity

Challenger

Challenger is the name of the second the American Space Shuttle built. Challenger’s maiden voyage was STS-6 in April 1983. Challenger traveled nine times into space before the orbiter was destroyed in an accident on January 28, 1986, during the launch of the STS-51L mission.

CHAN

Channel

CHARA

Characteristics

Chelicerae

Chelicerae are one of the anterior parts of appendages of an arachnid, often specialized as fangs.

Chemical oxygen demand

Chemical oxygen demand is the amount of oxygen required to oxidize the inorganic and organic matter in water.

Chemiluminescence

Chemiluminescense is light produced by chemical reaction usually at, or below, room temperature.

Chemoreceptive

Chemoreceptive means pertaining to chemoreception, the physiological detection of chemical stimuli. For example, the chemoreceptors in the carotid and aortic bodies are stimulated by chemical changes, such as hypoxia, in the composition of the blood.

Chemotactic

Chemotactic means relating to the attraction of living protoplasm to chemical stimuli whereby the cells are attracted or repelled by acids, alkalies or other bodies exhibiting chemical properties.

Chemotaxis

Chemotaxis is a response of motile cells or organisms in which the direction of movement is affected by the gradient of a diffusible substance. Differs from chemokinesis in that the gradient alters probability of motion in one direction only, rather than rate or frequency of random motion.

CHG

Change

CHIT

Crew Honest Input to Training

Chloride (Cl₂)

Chloride is a chemical compound containing chlorine. Chloride is the major extracellular ion and is significantly involved in the maintenance of proper water distribution, osmotic pressure and normal anion-cation balance in the extracellular fluid compartment.

Chloroform

Chloroform is a nonflammable, volatile liquid that was the first inhalation anesthetic to be discovered. It is a dangerous drug which can cause hypotension, myocardial and respiratory depression, cardiogenic shock, ventricular fibrillation, coma, and death if improper dosage is used. Delayed poisoning, even weeks after apparently complete recovery, can occur and serious vision or eye damage is frequently reported.

Chloroplast

A chloroplast is a cellular organelle that contains chlorophyll and is the site of photosynthesis and starch formation in plant cells.

Chocolate agar

Chocolate agar is agar to which blood has been added and heated until the blood becomes brown or chocolate in color.

Cholesterol

Cholesterol is a fat-soluble crystalline steroid alcohol found in animal fats and oils, and egg yolks and widely distributed through the body, especially in the bile, blood, brain tissue, liver, kidneys adrenal glands, and myelin sheaths of nerve fiber. It facilitates the absorption and transport of fatty acids and acts as the precursor of the synthesis of vitamin D at the surface of the skin, as well as for the synthesis of the various steroid hormones, including cortisol, cortisone, and aldosterone in the adrenal glands and of the sex hormones progesterone, estrogen, and testosterone.

Cholinergic

Cholinergic means secreting or stimulated by the neurotransmitter acetylcholine, or producing the effects of acetylcholine.

Chondritic

Chondritic means characterized by the presence of chondrules (rounded granules of cosmic origin often found embedded in meteoric stones and sometimes free in marine sediments).

Chondrocyte

A chondrocyte is a mature cartilage cell.

Chorioallantoic membrane

The chorioallantoic membrane is the extra-embryonic membrane formed by the fusion of the allantois with the serosa or false chorion. In mammals, it forms the fetal portion of the placenta; in avian embryos, it is fused with the shell.

Choroid plexus

The choroid plexus is a rich network of blood vessels located in the brain, and is responsible for the production of cerebrospinal fluid, the fluid which surrounds and cushions the brain and spinal cord.

Chromium

Chromium is a metallic, non-toxic element, with period table symbol Cr. Chromium does not have any function in the human body.

Chromium-51 (Cr51)

Chromium-51 (Cr₅₁) is an ion of the element chromium, which is used as a radioactive tracer because it binds to red blood cells. By measuring the amount of radioactivity produced by the Cr₅₁, red blood cell mass and survival can be measured.

Chromosomal

Chromosomal refers to chromosomes. Chromosomes contain DNA, which transmits genetic information. They are located in the nucleus of both plant and animal cells. In humans there are 46 chromosomes.

Chromosome

A chromosome is a body located within the cell nucleus of both plant and animal cells (normally 46 in humans). Each chromosome is composed of deoxyribonucleic acid (DNA) and specialized protein molecules, which convey genetic information.

Chromosome aberration

Chromosome aberration is any deviation from the normal number or morphology of chromosomes.

Chromotrophic acid

Chromotrophic (or chromotrophic) acid is used as a reagent in analytical methods and in chromotropes, which are dyes that have the property of changing from red to blue after treating a tissue specimen.

Chronic pulse/action relation

Chronic pulse/action relation means that for any contraction of a muscle, an electrical pulse, from a source such as the brain, must be generated. A specific delay between pulse generation and muscle action depends on various factors such as age, overall health, condition, mood, etc.

Chronobiology

Chronobiology is the aspect of biology concerned with the timing of biological events, especially repetitive or cyclic phenomena in individual organisms.

Chronotropic

Chronotropic means affecting the time or rate, as the rate of contraction of the heart.

CHX

Cabin Heat Exchanger

Configuration Inspection

CID

Cargo Integration Document

CID

Cable Interconnect Diagram

CIL

Critical Items List

CIM

Computer Input Multiplexer

CIN

Configuration Identification Number

CIO

Customer Integration Office

CIR

Cargo Integration Review

Circadian

Circadian means being, having, characterized by, or occurring in approximately 24-hour periods or cycles.

Circadian phase

All biological rhythms, including circadian rhythms, fluctuate between high and low values during a specified interval of time. The largest values are called "peaks", while the corresponding lowest values are called "troughs." The term "circadian phase" describes the time location during a 360 degree cycle, usually the peak or trough of the cycle with reference to some external point, such as local time, or the beginning of sleep.

Circadian rhythm

A circadian rhythm is a biological rhythm that repeats with a cycle of about 24 hours.

Circulation

Circulation refers to the cardiovascular system of the body in which the heart, together with two networks of blood vessels (arteries and veins), facilitates the movement of blood throughout the body. Circulation transports nutrients and oxygen to the tissues and removes waste products from the body.

Circulatory system

The circulatory system delivers oxygen and nutrients throughout the body by a complex network of vessels -- arteries, arterioles, capillaries and veins. Arteries, arterioles and the microscopic capillaries carry blood to all parts of the body and allow exchange of nutrients and wastes through capillary walls from blood to the tissues and organs. Veins carry deoxygenated blood back to the lungs for reoxygenation.

CIS

Central Integration Site

Cislunar

Cislunar refers to that region of space between the Earth and the Moon (or the Moon's orbit).

CITE

Cargo Integration Test Equipment

Citrate

A citrate is a compound of citric acid and a base.

Corrosive Liquid

CLA

Current Limiter Assembly

Class I

PAM-D Class Satellite

Class II

PAM-A Class Satellite

Class III

IUS Class Satellite

Class IV

Centaur Class Satellite

Clearance

Clearance is the removal of a substance from the blood via the kidneys. Kidney function can be tested by measuring the amount of a specific substance excreted in the urine in a given length of time.

Clinical medicine

Clinical medicine is the branch of medicine dealing with the study of actual patients and the diagnosis and treatment of disease at the bedside, as opposed to the study of disease by pathologic examination or research in basic sciences.

Clinostat

A clinostat is a device which uses a motor to rotate a wheel on which a sample under investigation (such as a plant in a pot) is attached. In the example of an attached plant, as the plant rotates, both the stem and roots will grow horizontally instead of exhibiting characteristic geotropic (gravity-oriented) responses.

CLS

Contingency Landing Site

Centimeter

Channel Electron Multiplier

Command Module

Controlled Material

CMB

Configuration Management Board

CMBD

Configuration Management Board Directive

CMC

Command Module Computer

CMC

Configuration Management Control

CMD

Command

CMG

Control Moment Gyro

CMO

Configuration Management Office

CMP

Configuration Management Plan

CMRR

Computer Materials Request Request

CMS

Configuration Management System

CNES

Centre Natianal D’Etudes Spatiales (French Space Agency). CNES is headquartered in Paris, France.

Communications Officer

Contracting Officer

Co-I

Co-Investigator

COAS

Course Optical Alignment Sight

COAX

Coaxial, Coaxial Cable

Cobalt

Cobalt is a tough lustrous silver-white magnetic metallic element that is related to and occurs with iron and nickel and is used especially in alloys.

COC

Certificate of Compliance

Cocci

Cocci are bacteria of round, spheroidal or ovoid form.

Coccus (plural cocci)

Coccus (plural cocci) refers to a bacterium with a rounded or spherical shape.

Codocyte

A codocyte is a red blood cell characterized by a bell-shaped appearance.

CofF

Construction of Facility

COFR

Certification of Flight Readiness

Cognitive

Cognitive means pertaining to the mental processes by which knowledge is acquired and used, including awareness, comprehension, judgment, memory and reasoning.

Cohesion

Cohesion is the ability to stick together.

COL

Carry-on-Lab

Colcemid

Colcemid is a compound that is used to stop cell division at the stage of metaphase.

Cold pressor test

The cold pressor test is a test measuring the tendency to develop essential hypertension. One hand is placed in ice water. An excessive rise in the blood pressure or an unusual delay in the return of normal blood pressure when the hand is removed from the water is believed to indicate that the individual is at risk for hypertension.

Collagen

Collagen is a protein that is the principal constituent of white fibrous connective tissue found in tendons, skin, bone, cartilage and ligaments; it is relatively inelastic (not flexible), but has a high tensile strength (ability to resist stretching).

Collagenous

Collagenous describes something composed of collagen. Collagen is a protein that is the principal constituent of white fibrous connective tissue. Collagen is found in skin, bone, cartilage, and ligaments. It is relatively inelastic (not flexible) but has a high tensile strength (able to resist forces of stretching).

Collimate

Collimate means to make straight. Collimation is the process, in X-ray, of restricting and confining the X-ray beam to a given area and, in nuclear medicine, of restricting the detection of emitted radiation from a given area of interest.

Collision

A collision is an encounter between two or more particles, photons, atoms or nuclei during which quantities of energy, momentum, and charge may be exchanged. The products of the collision may or may not be the same as the pre-collision particles. The collision may be actual contact or the close approach and deflection of the particles.

Colloidal

Colloidal describes atoms or molecules dispersed in a gas, liquid or solid, which resist sedimentation (setting to the bottom), diffusion (spreading out), and filtration.

Colony

A colony is a group of the same kind of animals, plants, or one-celled organism living or growing together.

Colony Forming Unit (CFU)

A Colony Forming Unit (CFU) is a colony that has grown on a filter that originated from one microorganism in the water sample.

Columbia

NASA operates four space shuttle vehicles, also called orbiters. Each one is named after famous historic sailing ships. Columbia is the oldest orbiter; its maiden voyage was also the first flight of a Space Shuttle, STS-1 in April 1981.

COM

Configuration Management

Combustion

Combustion is the burning of a material, i.e., a chemical change accompanied by the production of heat and light.

Commode

A commode is another term for a toilet.

COMPA

Compatibility

Compact bone

Compact bone tissue forms the external layer of all bones in the body. It is very dense bone with few open spaces and is found mainly in the long bones (i.e., those that absorb the weight of the body). Compact bone tissue provides protection and support and helps the long bones resist the stress of weight placed on them.

Complement

Complement refers to a group of about 20 serum proteins with the overall function of controlling inflammation. Complement proteins act to (1) assist white blood cells in phagocytosis, (2) attract white blood cells to sites of infection, (3) increase blood flow to the site of activation and increase permeability of capillaries to plasma molecules and, (4) damage to plasma membranes of bacteria cells, viruses or organisms by lysis of the cell.

Complement-fixing antibody

A complement-fixing antibody is a sensitizing substance; an antibody that combines with and sensitizes an antigen, leading to the activation of complement, sometimes, but not always resulting in lysis.

Complete blood count (CBC)

Complete blood count (CBC) is a determination of the number of red and white blood cells per cubic centimeter (1 milliliter) of blood.

Compliance (vascular)

Vascular compliance is the ability of blood vessels to become larger in diameter, or distend, to accommodate blood flow. It is calculated by dividing the volume change of a vessel by the pressure change produced by blood flow.

Compound

A compound is a pure and homogeneous substance consisting of atoms or ions of different elements in definite proportions, usually having properties unlike those of its constituent elements. A compound can be broken down into two or more other substances by chemical means.

COMSAT

Communications Satellite

Concanavalin A (ConA)

Concanavalin A is a chemical compound extracted from the jack bean. This compound agglutinates (clumps or sticks red blood cells together) the blood of mammals. It stimulates T-lymphocytes more vigorously than B-lymphocytes.

Concentric

A concentric contraction causes muscle movement that shortens the muscle.

Concomitant

Concomitant means designating one or more things, occurring simultaneously, that may or may not be interrelated.

Condensate

Condensate is the liquid formed from a vapor (gas) or a solid formed from a liquid through a chemical phase change. For instance, water condensate forms on the can of a cold soda as it sits at room temperature in a humid environment.

Conductivity

Conductivity is a measure of the ability of a material to conduct electrical charge.

Conductometrics

Conductometrics is determination of the amount of something in a solution by measuring the electrical conductivity of the solution.

Confluence

Confluence is the flowing together of two streams.

Conifer

Conifers (Latin, coniferophyta) are seed-bearing plants such as pine, fir, and spruce trees. Conifers are typically evergreen trees that inhabit cool temperate regions and have leaves in the form of needles or scales. The wood of conifers, which is called “softwood” in contrast to the hardwood of angiosperm trees, is widely used for timber and pulp.

Conjunctivitis

Conjunctivitis is the inflammation of the mucous membrane covering the anterior surface of the eyeball and lining of the eyelids.

CONN

Connector

Connective tissue

Connective tissue supports, binds, or separates more specialized tissues and organs of the body; "packing tissue" of the body. Types of connective tissue include bone, cartilage, tendon, ligament, adipose (fat), areolar and elastic.

Constituent

Constituent is a part of the whole; a component.

Consumables

Consumables are items that are meant to be used up, e.g. food.

Contact angle

A contact angle is the angle between the solid surface (plate or vessel) and the liquid surface.

Contaminants

Contaminants are substances that make another substance impure or corrupt by contact or mixture.

Contractile

Contractile means being capable of contracting or producing contraction (becoming shorter in length or size).

Contractile properties

Contractile properties are the abilities to shorten or to undergo a reduction in size; in the case of muscle, contraction means the muscle either shortens or increases in tension.

Contralateral

Contralateral means pertaining to the opposite side.

Control

A control is a test subject not exposed to the treatment or condition being studied by the experiment. Controls are used to isolate factors or conditions which vary in other subjects under experimentation.

Control system

A control system is one that provides operation, regulation, or guidance a machine or vehicle.

Control unit

The control unit of the Svet greenhouse provides automatic measurement of Svet environmental parameters every 4 hours.

Controlled frequency breathing

Controlled frequency breathing is a test where a subject is asked to adjust his breathing rate in time with a recording of normal, rapid and slow breathing rates.

Convection

Convection is the transfer of heat by the circulation or movement of heated parts in a liquid or gas. Convection is also the circulatory motion that occurs in a fluid which is at a nonuniform (or varying) temperature caused by the variation of the density of liquid at different temperatures and the action of gravity.

Coolanol

Coolanol is a ready-to-use 50/50 blend of premium quality anti-freeze and deionized water.

COP

Co-orbiting Platform

Copper

Copper is a malleable reddish-brown metallic element. It is a component of several important enzymes in the body and is important for red blood cell and bone formation.

CORE

Common Operational Research Equipment

Cornmealt-malt-yeast agar

Cornmealt-malt-yeast agar is a culture medium that is low in nutrients, used to study yeastlike and filamentous fungi; it suppresses vegetative growth, while stimulating sporulation of many species. It is widely used to produce the distinctive and rapidly diagnostic chlymydiospores of Candida albicans.

Correlate

Correlate means to show a relationship between entities.

Cortex

The cortex of an organ refers to the outer portion (layer) of the organ.

Corticosteroid

A corticosteroid is a steroid (a type of hormone) produced by the adrenal cortex of the adrenal glands. Corticosteroids all have similar chemical formulas, but serve a wide variety of functions in the body, including fluid and mineral regulation, metabolism, reproductive development, growth, the regulation of body temperature and the absorption of nutrients from the intestines.

Cortisol

Cortisol (hydrocortisone) is a steroid hormone synthesized and released by the cortex of the adrenal glands; it is important for normal carbohydrate metabolism and response to stress.

Corynebacteria

Corynebacteria are members of the family Corynebacteriaceae or the genus Corynebacterium, a group of nonmotile, aerobic to anaerobic bacteria. They stain irregularly and are club-shaped, being straight to slightly curved. These organisms are widely distributed in nature, and some are pathogenic.

COSMIC

Coherent Optical System of Modular Imaging Collectors

Cosmic rays

Cosmic rays are charged particles (ions) that originate outside the solar system. They move at high velocity and penetrate the earth's atmosphere at speeds approaching that of light.

Cosmos Biosatellite

The Cosmos Biosatellite Program consists of a group of Russian unmanned satellites which carry biological specimens, including rats and monkeys, into space to examine how space flight effects living systems.

Costodiaphragmatic

Coulter counter

A Coulter counter is a particle counter used for bacteria or eukaryotic cells; it works by detecting change in electrical conductance of a small aperture as fluid containing cells is drawn through.

Countermeasure

A countermeasure is a measure or action taken in opposition to another. Several countermeasures are used to counteract the negative effects of space flight, including the performance of rigorous exercise to reduce the degeneration of muscles and bones caused by disuse during stays in microgravity.

Coxsackie virus

Coxsackie virus is a picornavirus (included in the genus Enterovirus) of spherical shape that is about 28 nanometers in diameter. Picornoviruses cause a variety of diseases in man.

Control Panel

CPCB

Crew Procedures Change Board

CPCR

Crew Procedures Change Request

CPES

Crew Procedures Evaluation Simulator

CPM

Counts per Minute

CPS

Course Pointing System

CPSE

Common Payload Support Equipment

CPU

Computer Processing Unit

CPU

Central Processing Unit

Change Request

Conference Room

Cratylia mollis

Cratylia mollis is a type of shrub found in South America.

CRC

Cyclic Redundancy Check

Creatine

Creatine is a precursor of phosphocreatine which is an important energy reservoir in skeletal muscle. Phosphocreatine transfers its phosphate and energy to ADP to create ATP.

Creatine kinase

Creatine kinase is an enzyme present in skeletal and cardiac muscle and in the brain. Very high levels in the blood can indicate the presence of disease or an abnormality.

Creatine phosphokinase (CPK)

Creatine phosphokinase (CPK), also called creatine kinase, is an enzyme in muscle, brain and other tissues that catalyzes the transfer of a phosphate group from adenosine triphosphate to creatine, producing adenosine diphosphate and phosphocreatine.

Creatinine

Creatinine is a chemical substance excreted in the urine, which is derived from creatine and creatine phosphate. These substances serve to maintain adequate amounts of the substance adenosine triphosphate (ATP) which produces muscle contractions.

Crevicular

Crevicular means relating to any crevice. In dentistry, crevicular refers to the gingival crevice or subgingival space.

Critical current density

The critical current density represents the maximum current that can be transported by the film without losing superconductivity.

Critical transition temperature

The critical transition temperature represents the maximum temperature at which a material is superconducting.

CRN

Change Request Number

CRNE

Cosmic Ray Nuclei Experiment

Cross-coupling

Cross-coupling is a reflex that occurs when a visual scene which a subject is looking at is not aligned with the direction of gravity, for example, when the head is tilted from the vertical. Cross-coupling causes eye movements to align with the gravitational reference and not with the visual scene.

Cross-sectional Area

Cross-sectional Area (CSA) is the measurement of the area of a section formed by a plane cutting through an object, usually at right angles to an axis. For example, the cross-section of a muscle can be imaged using Magnetic Resonance Imaging (MRI). The cross section can be measured to determine the area and volume of the muscle.

CRR

Component Requirements Review

CRT

Cathode Ray Tube

CRT-KB

Cathode Ray Tube-Keyboard

CRU

Catalytic Research Unit

Cryogenic (CRYO)

Cryogenic means producing, or relating to the production of, low temperatures.

Cryogenically

Cryogenically refers to the storage or effects of materials in below-freezing temperatures. Biological specimens are sometimes stored in cryogenic conditions for long-term storage.

Crystallinity

Crystallinity refers to the crystal structure of the starch of a plant.

Crystallographic

Crystallographic means related to the study of crystal form and structure.

Corrosive Solid

CSA

CSCI

Computer Software Configuration Item

CSD

Contract Start Date

CSM

Command and Service Module

CSS

Core Segment Simulator

CST

Crew Software Training Aid

CTL

Control

CTPD

Crew Training and Procedure Division

CTPS

Cassette Tape Playback System

CTS

Crew Training Session

CTU

Central Timing Unit

Cultivate

To cultivate is to promote the growth of something (a biological sample, for instance).

Culture

A culture is a particular type of organism or cell growing in a laboratory nutrient medium.

Culture media

Culture media are nutrient substances, either solid or liquid, used for the cultivation, isolation, identification or storage of microorganisms or cells.

Culture medium

A culture medium is a nutrient substance, either solid or liquid, used for the cultivation, isolation, identification or storage of microorganisms or cells.

CUP

Control Unit and Processor

Configuration Verification

CVT

Concept Verification Test

Clockwise

CWEA

Caution and Warning Electronics Assembly

Cyanosis

Cyanosis is bluish discoloration of the skin and mucous membranes caused by an excess of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule.

Cyclic GMP

Cyclic guanosine monophosphate (Cyclic GMP) is a chemical substance that acts within cells to produce hormonal changes. It functions to allow hormones to affect only selected "target" cells to produce the desired changes in those cells.

Cystine

Cystine is a chemical substance which naturally occurs as a deposit in the urine, and can form a calculus (hard mineral formation) when deposited in the kidney.

Cytochemistry

Cytochemistry is the study of chemical compounds and their activities in living cells.

Cytochrome

Cytochrome is a chemical compound consisting of a protein linked to heme (the oxygen-carrier of the blood). Cytochromes are involved in many types of biological chemical reactions that support the life of cells.

Cytochrome oxidase

Cytochrome oxidase is an enzyme that acts as a chemical catalyst to facilitate chemical reactions occurring inside of cells as they consume nutrients and produce life-sustaining functions.

Cytogenetic

Cytogenetic refers to the science that links the study of inheritance (genetics) with that of cells (cytology) and is concerned mainly with the study of the chromosomes, their origin, structure, and functions.

Cytokines

Cytokines are chemicals involved in growth and regulation. They also influence bone resorption (breakdown) and formation.

Cytology

Cytology is the study of the structure and function of cells.

Cytomegalovirus

Cytomegalovirus is a group of herpetoviruses infecting man and other animals, many having special affinity for salivary glands, and causing enlargement of cells of various organs and development of characteristic inclusions in the cytoplasm or nucleus. Also known as visceral disease virus.

Cytoplasmic streaming

Cytoplasmic streaming is the movement or flow of cytoplasm, the living part of a cell external to the nuclear membrane.

Cytoskeleton

The cytoskeleton is a network of fibers running throughout the matrix of living cells that provides a framework for organelles, anchors the cell membrane, facilitates cellular movement, and provides a suitable surface for chemical reactions to take place.

Czapek Dox agar

Czapek Dox agar is a culture medium used to cultivate fungus species and to identify Aspergillus species.

Deck Area

Depth

D&C

Display and Control

D-A

Digital to Analog

D/L

Diameter to Length Ratio

Deutsche Spacelab Mission - 1

Desk Accessory (Macintosh)

DAC

Data Acquisition Camera

DAC

Digital to Analog Computer

DACh

Direct Access Channel

Damping

Damping is the dissipation of energy with time or distance. The term is generally applied to the attenuation of sound in a structure owing to the internal sound-dissipative properties of the structure or to the addition of sound-dissipative materials.

DAR

Deviation Approval Request

DAS

Data Analysis System

DAT

Digital Audio Tape

Decibel

DBA

Data Base Administrator

DBAS

Data Base Administration System

DBMS

Data Base Management System

DBS

Direct Broadcast Satellites

DBS

Direct Broadcast Sounder

Dow Corning

Direct Current

DC, dc

Direct Current

DC, dc

Dow Corning

DCL

Digital Command Language

DCMO

Documentation and Configuration Management Office

DCN

Document Change Notice

DCP

Data Collection Platform

DCR

Design Certification Review

DDC

Data Distribution Center

DDM

Drop-Dynamic Module

DDP

Deliverable Data Package

DDP

Design Development Plan

DDPC

Digital Data Processing Complex

DDR

Data Discrepancy Report

DDS

Data Display System

DDT&E

Design, Development, Text & Evaluation

DDU

Data Display Unit

Dedicated Flight Instrumentation; Dedicated Experiment

Deactivate

Deactivate means to render inactive or ineffective.

Dead space

Dead space is the area in the respiratory passages in which no gas exchange takes place.

Deafferentation

Deafferentation is a loss of the sensory nerve fibers, or their impulses, from a portion of the body.

Debris

Debris are the scattered remains of something broken or destroyed.

DEC

Digital Equipment Corporation

DEC net

Intercommunication Network Software from DEC

Decarboxylase

Decarboxylase is an enzyme that removes a molecule of carbon dioxide from a carboxylic group (e.g. from an a-amino acid, converting it into an amine).

Decompression

Decompression is the removal of pressure.

Decompression sickness (DCS)

Decompression sickness, also referred to as DCS, is a syndrome caused by bubbles of inert nitrogen gas forming in the tissues and bloodstream resulting from rapid changes in the ambient atmospheric pressure. DCS is manifested in two major forms, DCS I and DCS II. DCS I -- Decompression sickness involving only muscle and joint pain, fatigue and/or skin symptoms (itching, rash). DCS II -- Decompression sickness that includes symptoms involving the central nervous system, respiratory system or circulatory system.

Decondition

Decondition means to decrease in muscle strength or cardiovascular response.

Decontamination

Decontamination means to remove the contaminants or dangerous agents from something, e.g. buildings, clothing, the ground, etc.

DEF

Definition

Defibrillator

A defibrillator is a device which administers a controlled electric shock to restore normal heart rhythm in cases of cardiac arrest due to ventricular fibrillation (chaotic and abnormal pumping of the heart which does not allow the heart to pump blood effectively and is due to a disease or medical complication). The defibrillator administers the shock either through electrodes placed externally on the chest wall over the heart or directly to the heart after the chest has been opened surgically.

deg

Degree

Dehydration

Dehydration is the loss of water in body tissues. The condition may result from inadequate water intake and/or from excessive removal of water from the body; for example by sweating, vomiting or diarrhea.

Dehydroepiandrosterone (DHEA)

Dehydroepiandrosterone (DHEA) is a weakly androgenic steroid secreted largely by the adrenal cortex, but also by the testes. It is one of the principal components of urinary 17-ketosteroids.

DEMS

Dynamic Environment Measuring System

DEMUX,deMUX

Demultiplexer

Denitrogenation

Denitrogenation is the elimination of nitrogen from the lungs and body tissues by breathing gases devoid of nitrogen.

Densitometer

A densitometer is an electronic instrument used to measure the density, or degree of darkening, of a photographic film or plate, a liquid or material deposited on a chromatographic plate or electrophoresis medium, by photometrically recording its transparency.

Densitometry

Densitometry is the measurement of the density or compactness of bone. It is also an indirect method of determining body composition; using this method, percentage of body fat is computed from bone density (the ratio of body weight to body volume).

Dental caries

Dental caries is a localized, progressively destructive disease of the teeth that starts at the external surface or enamel and dissolves the inorganic components. Organic acids are produced on or next to the tooth by the enzymatic action of microorganisms in the bacterial plaque on carbohydrates. The initial demineralization is followed by an enzymatic destruction of protein. Cavities and bacterial infection follow. In the dentin, demineralization in the tubules is followed by bacterial invasion and destruction of the organic matrix. Untreated dental caries progresses to the pulp, resulting in infection and its consequences.

Dental plaque

In dentistry, dental plaque is a mass of microorganisms attached to the surface of a tooth. Depending on bacterial activity and environmental factors, it can result in caries, calculus or inflammatory changes in adjacent tissue.

Dental prophylaxis (plural prophylaxes)

Dental prophylaxes are a series of procedures whereby calculus, stain, and other accretions are removed from the clinical crowns of the teeth, and the enamel surfaces are polished.

Dental pulp

Dental pulp (pulpa dentis) is the soft tissue within the pulp cavity, consisting of connective tissue containing blood vessels, nerves, and lymphatics, and at the periphery a layer of odotolasts capable of internal reair of the dentin.

Deoxypyridinoline

In the process of bone resorption, the type I collagen cross linking molecule deoxypyridinoline (Dpd) is released into the circulation and cleared by the kidney. Dpd in urine can be measured as a specific marker of bone resorption.

Deoxyribonucleic acid (DNA)

Deoxyribonucleic acid (DNA) is a complex molecule found in the chromosomes of almost all organisms which acts as the chemical storage for primary genetic material. DNA contains the chemical "code" which allows traits and inherited characteristics to be passed down from organism to organism.

DEP

Dedicated Experiment Process

Deploy

To deploy is to station or distribute systematically over an area (in preparation for operation or activity).

Deposition

Deposition is the precipitation of mineral matter from solution, such as the deposition of agate, vein quartz, etc.

Dermatitis

Dermatitis is the inflammation of skin.

Dermatophyte

A dermatophyte is a fungus that causes infections of the skin, hair and/or nails, i.e., keratinized tissue.

DES

Data Exchange System

Desc

Description

DESCPT

Description

Desiccation

Desiccation means dehydration.

Desorb

Desorb means to remove by the reverse of adsorption or absorption.

DEST

Destination

Detailed Supplementary Objective (DSO)

A Detailed Supplementary Objective (DSO) is a NASA-sponsored investigation performed voluntarily by Space Shuttle crewmembers, who serve as the test subjects. These studies are designed to require minimal crew time, power and stowage. Biomedical DSOs focus on operational concerns, including space motion sickness, cardiovascular deconditioning, muscle loss, changes in coordination and balance strategies, radiation exposure, pharmacokinetics and changes in the body’s biochemistry. Key hardware and procedures have been tested and verified as DSOs prior to use in support of more costly, complex life sciences investigations. Data may be collected before, during and after flight, and usually subjects from more than one mission participate in each DSO. Some DSOs were also part of the Extended Duration Orbiter Medical Project.

Deuterium

Deuterium is an isotope of hydrogen (same number of protons in the nucleus, but a different number of neutrons).

DEV

Development

Development Test Objective (DTO)

At the beginning of the Shuttle Program, the Space Transportation System (STS) Program Office established a procedure for testing and refining Orbiter and subsystem performance capabilities, and for evaluating new hardware and procedures. Procedures involving the Orbiter, its subsystems, and its support equipment were designated Development Test Objectives (DTOs). All other operationally relevant procedures were classified as Detailed Supplementary Objectives (DSOs).

Developmental biology

Developmental biology research is concerned with the influences of gravity and microgravity on reproduction, differentiation, growth, development, life span, aging and subsequent generations of animals.

Dewar

The Dewar is a thermos-like container used to store protein samples and keep them frozen until the liquid nitrogen thaws.

Dexamethasone

Dexamethasone is a glucocorticoid which is prescribed in the treatment of inflammatory conditions.

Dexterity

Dexterity is skill in using the hands or body.

Dextroamphetamine

Dextroamphetamine is a form of amphetamine, a drug that stimulates the central and peripheral nervous systems.

Dextroamphetamine sulfate

Dextroamphetamine sulfate is a central nervous system stimulant.

Dextrose

Dextrose is a simple sugar found in the blood (also known as glucose).

DFAST

Data Flow and Analysis Timeline

DFI

Dedicated Flight Instrumentation

DFPT

Delayed Flight Profile Test

DFRC

Dryden Flight Research Center

Diagnostic

DGDSO

Ground Data System Officer

DGP

Diagnostic Package

DHF

Data Handling Function

DHU

Data Handling Unit

Data Integrator

Discrete Input

Dialysis

Dialysis is a form of diffusion, i.e., a form of filtration to separate a crystalloid from colloid substance in a solution by interposing a semi-permeable membrane between the solution and water. The crystalloid substances pass through the membrane into the water on the other side, the colloids do not.

Dialyze

Dialyze means to prepare by diffusion through a semipermeable membrane.

Diaphragm

A diaphragm is a thin dome-shaped skeletal muscle that separates the thoracic and abdominal cavities. The diaphragm plays an important role in breathing: it contracts with each inspiration, becoming flattened downward and increasing the volume of the thoracic cavity so that air is drawn into the respiratory tract, and then, with expiration, it relaxes and is restored to its dome shape.

Diastole

Diastole is the phase of the heart during which the heart muscle relaxes, causing blood to fill the heart chambers.

Diastolic blood pressure

Diastolic blood pressure is the blood pressure measured during diastole, or the dilation of the heart cavities, during which they fill with blood. The lowest blood pressure measured in the large arteries is about 80 millimeters of mercury under normal conditions for a young, adult male.

Dichlorodifluoromethane

Dichlorofluoromethane is a chlorofluorocarbon derived from methane (freon). Freons are gaseous compounds used as refrigerants, cleaning solvents and aerosol propellants.

Didactic

Didactic means pertaining to instruction or teaching.

Diencephalon

The diencephalon is the portion of the embryonic brain that develops into the thalamus, hypothalamus, and associated structures, all of which make up the diencephalon (hindbrain) in the adult. It includes structures important in the visual pathway. Some sources consider the adult diencephalon to be part of the brainstem.

Differential count

A differential count is an estimate of the percentage of white blood cell types which make up the total white blood cell count.

Differentiation

Differentiation, in embryology, is the process in embryonic development during which unspecialized cells or tissues become specialized for particular functions. Differentiation, in oncology, is the degree of similarity or difference of tumor cells to the structure of the organ from which the tumor arose.

Diffusing capacity

The diffusing capacity is the volume of a gas that diffuses through a membrane each minute for a pressure difference of 1 mmHg.

Diffusion

Diffusion generally refers to the spreading out or dispersing of a material. Chemical diffusion is a passive process in which there is a net or greater movement of molecules or ions from a region of high concentration to a region of low concentration until equilibrium is reached.

Diffusion coefficient

The diffusion coefficient is a numerical measure of the diffusion property that is constant for a specified system. Diffusion refers to the spreading out or dispersing of a material. Chemical diffusion is a passive process in which there is a net or greater movement of molecules or ions from a region of high concentration to a region of low concentration until equilibrium is reached.

Digestive

Digestive is a term relating to the digestive system, which comprises the digestive tract from the mouth to the anus and all associated glands and organs.

Digital

Digital is a term for a transmission mode in which data is measured in discrete intervals. Digital electronics systems measure voltage being turned on an off through a series of numbers using only 1s and 0s.

DIL

Discrete Inputs, Low Level

DIL

Digital Image Library

Dilatancy

Dilatancy is the property of increasing viscosity with an increase in applied force, such as a shear force or pressure caused by expansion of volume. Cytoplasm exhibits dilatancy.

Dilation

Dilation is the physiologic, pathologic, or artificial enlargement of a cavity, canal, blood vessel or opening.

Dilution series

A dilution series is a method for counting the number of viable cells in a suspension; a sample is diluted to the point where an aliquot, when plated, yields a countable number of separate colonies.

Dimethyl sulfoxide (DMSO)

Dimethyl sulfoxide (DMSO) is a penetrating solvent, that enhances the absorption of therapeutic agents and has been proposed as an effective analgesic and anti-inflammatory agent in arthritis and bursitis.

Dioctyl phthalate (DOP)

Dioctyl phthalate (DOP) is used as a plasticizer in a variety of products. These products include polyvinylchloride (PVC) and other polymers such as rubber, cellulose and styrene. A number of packaging materials and tubings used in the production of foods and beverages also contain DOP. Disposal of these products (incineration, landfill, etc.) results in the release of DOP into the environment. Acute exposure to DOP can result in mild gastrointestinal disturbances, nausea and vertigo. DOP may also have the potential to cause cancer from long-term exposure at levels above the Environmental Protection Agency's (EPA) set Maximum Contaminant Level (MCL).

Diphtheria

Diphtheria is an infection caused by the highly potent toxin of the bacterium Corynebacterium diphtheriae, which produces degeneration in peripheral nerves, heart muscle and other tissues.

Diphtheroid

A diphtheroid is a bacterium (especially genus Corynebacterium) that resembles the bacterium of diphtheria but does not produce diphtheria toxin.

Diploid

Diploid means denoting the state of a cell containing twice the normal gametic number of chromosomes, one member of each chromosome pair derived from the father and one from the mother; the normal chromosome complement of somatic cells.

Dipyridamole

Dipyridamole is a coronary vasodilator which is prescribed for the long term treatment of angina.

Discocyte

A discocyte is a red blood cell that is in the normal, biconcave disc shape.

Distal

Distal means anatomically situated away from the origin or point of attachment, or from the middle line of the body. It is specifically applied to the extremity or distant part of a limb or organ. For example, the fingers are the most distal portion of the arm in relation to the torso.

Diuresis

Diuresis is the increased secretion of urine by the kidneys. This normally follows the intake of more fluid than the body requires, but can be stimulated by administering a drug called a diuretic or by the fluid shift that occurs in microgravity.

Diurnal

Diurnal means pertaining to or occurring in the daytime; opposite of nocturnal. Diurnal also means repeating once each 24 hours.

Dedicated Laboratory

DL-1

Dedicated Laboratory-1 (Mission)

DLSL

Dedicated Life Sciences Laboratory

Docking Module

DM stands for the diffusing capacity of the alveolar capillary membrane, the outer membrane of the smallest blood vessels, called capillaries, in the lung.

DMA

Direct Memory Access

DMIS

Data Management Information System

DMOO

Data Management and Operations Office

DMP

Data Management Plan

DMS

Data Management System

Discrepancy Notice

DNA fingerprinting

DNA fingerprinting is a method used to identify individuals within a species. The DNA fingerprint itself is the individual-specific autoradiographic banding pattern (shown by electrophresis) that is produced when DNA is digested with a restriction endonuclease.

Discrete Output

DOD

Department of Defense

Doff

To doff is to remove an article of clothing.

DOH

Discrete Outputs, High Level

DOL

Discrete Outputs, Low Level

DOMSAT

Domestic Satellite

Don

To don is to put on an article of clothing to wear.

Doppler ultrasound

Doppler ultrasound is a procedure that uses sound waves to evaluate soft-tissue organs in the body, such as the liver, kidneys and gallbladder. The ultrasound machine is made up of computers and handheld instruments called transducers. A transducer looks like a wand or microphone. Warm gel is used to remove the air between the skin and the transducer. The wand is moved across the skin, producing a picture on the computer screen.

Dorsal

Dorsal means relating to or situated at or close to the back of the body or to the posterior part of an organ.

Dorsiflexion

Dorsiflexion is the backward flexion of the foot, toes, hand or fingers, (bending toward the upper surface).

Dorsiflexor

The dorsiflexor is a muscle which turns the foot, toes, hands or fingers upward towards the upper surface.

Dorsomedial

The term dorsomedial is used in medicine to refer to the central, back region of the body area being discussed. The term comes from the Latin dorso (posterior or back) and medial (relating to the middle or center). Thus the term “dorsomedial aspect of the thigh” means centrally located behind the thigh.

Dose equivalent

A dose equivalent is the absorbed radiation dose adjusted to allow for the biological harmfulness of different kinds of radiation; it is measured in sieverts (Sv).

Dose rate

Dose rate is the ionizing radiation dose delivered per unit of time.

Dosimeter

A dosimeter is a device used to record the amount of radiation received by workers from X-rays or other radiation, usually consisting of a small piece of photographic film in a holder attached to the clothing. At regular intervals the film is examined to determine the amount of radiation it (and therefore, the wearer) has received.

Dosimetry

Dosimetry is the accurate determination of radiation dosage, i.e., the quantity of radiation received over a given period of time.

DOSR

Design and Operations Status Review

DOT

Department of Transportation

Doubly labeled water

Doubly labeled water is a method of measuring metabolism by using two stable, non-radioactive chemical isotopes: deuterium (2H) and oxygen (18O). This method has the advantage that the two metabolic processes in the body involving hydrogen and oxygen can be monitored simultaneously. Deuterium leaves the human body in urine, while the labeled oxygen is found in urine and exhaled CO2. The difference between the two isotopes found in the urine sample is equal to the rate of CO2 production, which indicates energy consumption.

Data Processing

Double Precision Floating Point

DPI

Dots Per Inch

DPS

Data Processing Supervisor

Data Requirement

DR&C

Data Research and Control

DRAM

Dynamic Random Access Memory

DRD

Data Requirements Document

Drechslera

Drechslera is a saprobic genus of fungi, frequently recovered in the clinical laboratory, characterized by conidia attached to a zigzagged conidiophore. Species in the genus may cause disease in humans, cats, and horses.

DRF

Data Request Form

DRIP

Data Requirements Implementation Plan

DRL

Data Requirement List

Drosophila

Drosophila are a species of fruit flies. Drosophila are often used in genetic research because the larvae possess large chromosomes in their salivary glands. Fruit flies have a short life cycle and produce a large number of offspring, which makes them an ideal species for scientific study.

DRS

Data Base Software (Data Retrieval System)

DRS

Data Requirement Status (Manager)

DRTS

Data Relay Tracking Satellite

Discipline Scientist

DSAD

Data Systems and Analysis Directorate

DSIP

Data Systems Implementation Plan

DSN

Deep Space Network

DSP

Data System Plan

DSPL

Display

DSR

Database Support Request

DSSP

Data Systems Support Plan

DSSR

Data Systems Support Request

Delayed Time

Dynamic Environment Measuring System Tester or DEMS Tester

DTA

Differential Thermal Analysis

DTE

Digital Television Equipment

DTP

Desktop Publishing

DTS

Data Transmission System

Dual Energy X-ray Absorptiometry (DEXA)

Dual Energy X-ray Absorptiometry (DEXA) provides accurate measurements of whole and regional body composition (fat, bone and muscle tissue).

Ductile

Ductile is the ability of a substance to be hammered thin.

DVU

Design Verification Units

DWG

Drawing

DWG #

Drawing Number

Dynamometer

A dynamometer is an instrument used to measure the force of muscular contraction.

Dysbarism

Dysbarism is a reaction to sudden change in ambient pressure, such as rapid exposure to the lower atmospheric pressures of high altitudes. It is marked by symptoms similar to those of decompression sickness.

Dysfunction

A dysfunction is an abnormal function, that is either diseased, faulty or bad.

Dysrhythmia

Dysrhythmia is any abnormality in the rate, regularity or sequence of heart activity.

Estimated

E-rosette

E-rosette is a technique used to identify cell surface receptors. Signal cells, carrying a receptor-binding substance on its surface, are mixed with receptor-bearing cells. When the receptor-bearing cells bind to the signal cells, they form “rosettes."

Each

EAFB

Edwards Air Force Base

EAPC

Equivalent Additions per Cycle

EAV

Experiment Assembly and Verification

EBA

Electron Beam Accelerator

Experiment Computer

EC-HRM

Experiment Computer - High Rate Multiplexer

ECAS

Experiment Computer Application Software

Eccentric

Eccentric muscle movement causes a lengthening of the muscle, that is, movement of a muscle away from the body.

ECDS

Experiment Command and Data System

ECE

Experiment Checkout Equipment

ECE

Experiment Coordinating Engineer

ECF

Electro-Conductive Film

ECG

Electroephitaxial Crystal Growth

Echinocyte

An echinocyte is a red blood cell that has changed from the normal, biconcave disc shape to a sphere with short, sharply pointed projections. Aging of blood in circulation, in a tube or on a slide is the most common cause of the discocyte to echinocyte transformation.

Echocardiogram

An echocardiogram is an image of the heart and major blood vessels produced by echocardiograpy.

Echocardiographic

Echocardiographic means pertaining to an echocardiograph, an instrument used to produce ultrasound images of the heart and major blood vessels, or to the record it produces or the process of making the record.

Echocardiography

Echocardiography is the use of ultrasound (sound waves at extremely high frequencies) to produce images of the heart and major blood vessels.

ECIO

Experiment Computer Input Output

ECLS

Environmental Control and Life Support

ECLSS

Environmental Control and Life Support Subsystem

ECLSS

Environmental Control and Life Support System

ECMA

European Computer Manufacturing Association

ECO

Engineering Change Order

Ecological

The term ecological relates to the total complex of interrelationships among living organisms, encompassing the relations of organisms to each other, to the environment, and to the entire energy balance within a given ecosystem.

Ecology

Ecology is the branch of biology concerned with studying the interrelationships of living organisms, specifically their relationships to each other and to the environment.

ECOS

Experiment Computer Operating System

ECP

Engineering Change Proposal

ECR

Engineering Change Request

ECS

Environmental Control Subsystem

ECS

Environmental Control System

Ectopic

Ectopic means "out of place" and is said of an organ which is not in its proper position, or of a pregnancy occurring elsewhere than in the cavity of the uterus. In cardiography, it denotes a heart beat that has its origin in some abnormal focus other than the sinoatrial node (the area of the heart where heart beats normally originate).

Experiment Document

Experiment Definition

EDAX

Energy Dispersive X-Ray Analysis System

EDB

Engineering Data Base

EDC

Experiment Development Center

EDCR

Engineering Design Change Request

Edema

An edema (or dropsy) is an excessive accumulation of fluid in the body tissues. The resultant swelling may be local, associated with an injury or inflammation, or general, as occurs in heart or kidney failure.

EDF

Engineering Data Function

EDIS

Experiment Data Interface System

EDL

Linkage Editor

EDOMP

Extended Duration Orbiter Medical Project

EDP

Electronic Data Processing

EDR

Experiment Design Review

EDRS

European Data Relay Satellite

EDU

Experiment Development Unit

EED

Electrical Explosive Device

EEE

Electrical, Electronics, and Electromechanical

EEVT

Electrophoresis Equipment Verification Test

Effective renal plasma flow (ERPF)

Effective renal plasma flow (ERPF) is often also referred to as plasma clearance, and refers to the ability of the kidneys to clean or clear the plasma of unwanted substances. It is a rate, usually expressed in milliliters of cleared substances per minute (ml/min).

Effector

An effector is a cell or organ that produces a physiological response when stimulated by a nerve impulse. Examples of effectors include muscles and glands.

Efferent

Efferent means conducting (fluid or a nerve impulse) outward from a given organ or part thereof, e.g. the efferent connections of a group of nerve cells, efferent blood vessels, or the excretory duct of an organ.

Efficacy

Efficacy is the power or capacity to produce a desired effect; effectiveness.

Effluent

Effluent refers to something that flows out or forth.

EFS

Experiment Flight Software

Egocentric

Egocentric means to place extreme concentration or attention on one's self. Egocentric motor strategies are those in which the subject concentrates on a body frame of reference rather than on the external world.

Egress

Egress is the act of getting out of a structure, usually a spacecraft in this database. As a verb, it means to get out of a spacecraft.

EGSE

Electrical Ground Support Equipment

Equipment Item

Experiment Integrator

EIA

Electronic Industry Association

Eicosanoid

Eicosanoid is a lipid mediator of inflammation derived from the 20-carbon atom arachidonic acid (20 in Greek is "eicosa") or a similar fatty acid. The eicosanoids include the prostaglandins, prostacyclin, thromboxane, and leukotrienes.

EIE

Experiment Interface Engineer

EIS

Electrical Integration System

EISB

Electronics Instrument Services Branch

EIU

Engineer Interface Unit

Ejection fraction

The ejection fraction is the fraction of the end-diastolic volume of the heart that is ejected from the ventricles during systole.

Ejection time

Ejection time is the period during which, in the heart, ventricular pressures push the heart valves open and the blood in the ventricles is forced into the aorta, the main artery leading from the heart.

Elevation

Elbow extensor

The elbow extensor is the muscle (called the triceps brachii) that extends the elbow joint.

Elbow flexor

The elbow flexor is the muscle (called the biceps brachii) which acts to flex the elbow.

Electrical systole

Electrical systole is the electrical discharge that precedes the contraction of the heart muscle. It is also known as the QRS complex. This electrical discharge depolarizes the myocardium (heart muscle) and results in mechanical systole or the muscular contraction of the heart.

Electro-oculogram (EOG)

An electro-oculogram is a record of the electric currents that result from changes in standing potential between the front and back of the eyeball as the eyes move.

Electro-oculograph

An electro-oculograph is an instrument used to record eye movements by measuring small electrical charges with tiny electrodes attached to the skin at the inner and outer corners of the eye.

Electro-oculography (EOG)

Electro-oculography (EOG) is the method of recording eye movements by placing electrodes on the skin around the eye. The electrodes measure the small changes in the electrical potentials in the skin as the eyeball moves.

Electro-osmosis

Electro-osmosis is the diffusion of a substance through a membrane in an electrical field.

Electrocardiogram (ECG or EKG)

An electrocardiogram (ECG or EKG) is a graphic record of the heart's electrical currents.

Electrocardiograph

An electrocardiograph is an instrument used to record the potential of electrical currents that traverse the heart and initiate its contraction.

Electrode

An electrode is a small conductive device used to establish electrical contact with the body (animal or human). The electrical current generated by the human body is conducted through the electrode to an instrument that records the electrical potential of these currents. Instruments that use electrodes include the electrocardiograph (ECG), electroencephalograph (EEG), electrooculograph (EOG) and electromyograph (EMG).

Electroencephalogram (EEG)

An electroencephalogram (EEG) is a graphic record of the electrical activity in the brain obtained by an electroencephalograph. The pattern of the EEG reflects the state of the patient's brain and the level of consciousness in a characteristic manner. A recording of the electrical impulses of the brain can be used to diagnose certain diseases (such as epilepsy), furnish information regarding sleep and wakefulness, and confirm brain death.

Electrofusion

Electrofusion is the process of fusing two separate cells by applying an electric current. For example, plant cell protoplasts of two different species of sunflowers were fused during the D-2 Space Shuttle mission by the application of electric pulses of short duration and high intensity. As the cells came in contact with each other, their cell membranes combined, forming a single larger cell, or hybrid, with new characteristics distinct from the two original parent cells.

Electrogenesis

Electrogenesis refers to the creation of electrical energy.

Electrolysis

Electrolysis is the decomposition of a salt or other chemical compound by means of an electric current.

Electrolyte

An electrolyte is an element or compound that, when dissolved or melted in water or other solvent, dissociates into ions and is able to conduct electric current. Electrolyte concentrations differ between the blood plasma, interstitial fluid and cell fluid, which affects the movement of substances between these fluids. Proper quantities of principal electrolytes and balance among them are critical to normal metabolism and function.

Electromagnetic interference (EMI)

Electromagnetic interference (EMI) is any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics/electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation products, and the like.

Electromyogram (EMG)

An electromyogram (EMG) is a record of electrical currents generated in an active muscle.

Electromyographic

Electromyographic means pertaining to an electromyograph (EMG), an instrument that records electrical currents generated in an active muscle, or to the record it produces or the process of making the record.

Electromyography

Electromyography is the recording of electrical currents generated in an active muscle using an instrument called an electromyogram (EMG). EMG recordings can be used to ascertain causes of muscular weakness, paralysis, involuntary twitching, and abnormal levels of muscle enzymes; EMGs can also be used as part of biofeedback studies.

Electron microscopy

Electron microscopy is inspection with an electron microscope. An electron microscope utilizes streams of electrons deflected from their course by an electrostatic or electromagnetic field for magnification of objects. The final image is viewed on a fluorescent screen or recorded on a photographic plate. Because of greater resolving power, images may be magnified up to 40,000 diameters, more than any other type of microscope.

Electron spectroscopy for chemical analysis (ESCA)

Electron spectroscopy for chemical analysis (ESCA, also known as X-ray photoelectron spectroscopy or XPS) is a surface analysis technique used for obtaining chemical information about the surfaces of solid materials. An X-ray beam excites a solid sample, resulting in the emission of photoelectrons. An energy analysis of these photoelectrons provides information about the elements and chemical bonding on the surface of the sample.

Electronystagmograph

An electronystagmograph is an electronic device used to collect data on the nystagmic properties of eye movement by detecting and recording the nerve signals that cause such movements.

Electrophoresis

Electrophoresis is the technique of separating electrically charged particles, particularly proteins, in a solution by passing an electric current through the solution. The rate of movement of the different components depends upon their charge, so that they gradually separate into bands. Electrophoresis is widely used in the analysis of body chemicals, such as the analysis of the different proteins in blood serum.

Ellipsometry

Ellipsometry is the measurement of the change in ellipticity (the quality of asymmetrical intensity distribution in a laser beam, as opposed to a circular distribution) of an optically polarized light beam after reflection from a surface in a particular manner.

ELM

Experimental Logistics Module

Elodea

Elodea is any of a small American genus of submerged aquatic monocotyledonous herbs.

ELS

Emergency Landing Site

ELT

Emergency Locater Transmitter

ELV

Expendable Launch Vehicle

Electromagnetic

Electromagnetic Energy

Engineering Model

Exception Monitor

Experiment Manager

Embryo

An embryo is an animal at the early stage of development, before birth.

Embryo sac

An embryo sac is a large cell that develops in the ovule of flowering plants. It contains the egg cell which, when fertilized, becomes an embryo, and then, eventually, a seed.

Embryogenesis

Embryogenesis is the formation and development of an embryo.

Embryological

Embryological refers to an embryo, an animal at the early stage of development before birth.

Embryonate

Embryonate means containing an embryo.

Embryonic

Embryonic refers to an embryo, an animal at the early stage of development before birth.

EMC

Electromagnetic Compatibility

EMEC

Electromagnetic Effects Capability

EMI

Electromagnetic Interference

EMI/EMC

Electromagnetic Interference/Electromagnetic Compatibility

Emittance

Emittance is a rating of the ability of a material to give off heat as radiant energy. The emissivity of a material is expressed as a fraction. Emittance values range from 0.05 for brightly polished metals to 0.96 for flat black paint.

EMP

Engineering Management Plan

Emphysema

Emphysema is a pulmonary disorder involving over-distention and destruction of the air spaces in the lungs.

EMS

Electromagnetic Susceptibility

EMS

Engineering Master Schedule

EMU

Extravehicular Mobility Unit

End diastolic cardiac volume

End diastolic volume is the volume measured in each ventricle at the end of diastole (period of the heart's relaxation), which normally increases to about 130 ml.

End systolic cardiac volume

End systolic cardiac volume is the volume measured in each ventricle at the end of systole (period of the heart's contraction), which normally decreases to about 60 ml.

End tidal carbon dioxide

End tidal carbon dioxide is the concentration of carbon dioxide in exhaled breath at the end of each expiration.

Endemic

Endemic, in relation to a microorganism or disease, means indigenous to a geographical area or population.

Endocrine

Endocrine means secreting internally, most commonly into systemic circulation.

Endocrine glands

The endocrine glands manufacture one or more hormones and secrete them directly into the bloodstream. Endocrine glands include the pituitary, thyroid, parathyroid, adrenal, ovary, testis, placenta and part of the pancreas.

Endocrine secretions

The endocrine secretions are hormones secreted directly into the bloodstream and not through a duct to the exterior.

Endocrine system

The endocrine system refers to all of the body's hormone-secreting glands. This system works in conjunction with the nervous system to control the production of hormones and their release into the circulatory system.

Endocrinology

Endocrinology is the study of the structure and functions of the endocrine glands and the diagnosis and treatment of disorders of the endocrine system.

Endosteal surface

The endosteal surface is the inside surface of bones which border the bone marrow cavity.

Endothelial cells

Endothelial cells are the inside cellular lining of a tissue.

Endotoxin

An endotoxin is a poison found in the cell membrane of some gram-negative bacteria, which is released when the cell is damaged or destroyed.

Enema

Enema is the injection of a liquid into the rectum through the anus for cleansing, as a laxative, or for other therapeutic purposes.

Energy expenditure

Energy expenditure is the amount of metabolic energy used, or calories burned, by an individual under specified conditions.

Energy metabolism

Energy metabolism refers to the transformation of chemical energy from food to mechanical energy or heat.

Energy-dispersive spectroscopy

Energy-dispersive spectroscopy is analysis of the chemical elements in a structure by directing a beam of electrons at the structure and examining the energy and intensity distribution of the X-rays thus produced.

ENG

Electronsystematography

ENG

Engineer

ENG

Electronsyatmography

Engorgement

Engorgement means distention or vascular congestion of body tissues.

Enteric

Enteric means relating to the intestine.

Enteric cytopathogenic human orphan (ECHO) virus

The enteric cytopathogenic human orphan (ECHO) virus is an enterovirus isolated from man that belongs to the family Picornaviridae. While there are several inapparent infections, certain of the several serotypes are associated with fever and aseptic meningitis, and some appear to cause mild respiratory disease.

Enteritis

Enteritis is the inflammation of the intestine, especially of the small intestine.

Enterobacter

Enterobacter is a genus of aerobic, facultatively anaerobic, nonsporeforming, motile bacteria containing Gram-negative rods. The cells are peritrichous, and some strains have encapsulated cells. Glucose is fermented with the production of acid and gas. These organisms occur in feces, sewage, soil, water, and dairy products and are recognized as the agent of common infections of the urinary tract, lungs, or blood.

Enterococcus faecalis

Enterococcus faecalis is a species of non-motile bacteria having gram-positive spherical cells, occurring in chain-like groups. They are commonly found in the intestinal tract of humans.

Enterovirus

Enterovirus is any of a group of picornaviruses (small RNA-containing viruses such as the poliomyelitis virus) that typically occur in the gastrointestinal tract but may be involved in respiratory ailments, meningitis and neurological disorders.

Environmental monitoring

Environmental monitoring is the quantification and tracking of physical, chemical, biological and radiological factors in a defined environment, such as the interior of a spacecraft.

Enzyme

An enzyme is usually a protein that, in small amounts, speeds up the rate of a biological reaction without itself being used up in the reaction (i.e., it acts as a catalyst). For example, enzymes present in the digestive juices of the stomach break down food into simpler compounds to be absorbed into the body.

Enzyme histochemistry

Enzyme histochemistry is the study of the chemistry of enzymes.

Enzyme Linked Immunosorbent Assay (ELISA)

Enzyme Linked Immunosorbent Assay (ELISA) is used for diagnosis of specific infectious diseases. An enzyme is used as the indicator system; when the enzyme and the antigen-antibody complex bind, a color indicator or other easily recognizable sign occurs.

Engineering Order

EOD

Earth Observations Division

EOM

Earth Orbiting Mission

EOM

End of Message

EOM+

End of Mission + (Days)

EOS

Earth Observation Satellite

EOS

Earth Observing System

Eosinophil

An eosinophil is a variety of white blood cell distinguished by the presence in its cytoplasm of coarse granules; its function is poorly understood, but it is known to be capable of ingesting foreign particles, is present in large numbers in lining or covering surfaces of the body, and is involved in allergic responses.

EPBD

Electric Power Branching Distributor

EPBD

Experimental Power Bus Distribution

EPC

Experiment Procedures Coordinator

EPDB

Electric Power Distribution Box

EPDS

Experimental Power Distribution System (Subsystem)

EPH

Experiment Peculiar Hardware

Ephemeral

Ephemeral is anything that lasts for a brief time; transitory.

Ephyrae

Ephyrae are free-swimming larvae of a jellyfish that result from the strobilation (division into segments) of a larval polyp (juvenile form of a jellyfish).

Epidemiological

Epidemiological means of or relating to epidemiology, a branch of medical science in which the incidence, distribution and control of disease is studied. This not only applies to the study of such classic epidemics as plague and cholera, but also includes all forms of disease that relate to the environment and ways of life, such as links between smoking and cancer, diet and coronary disease, and communicable diseases.

Epinephrine

Epinephrine (also called adrenaline) is a hormone secreted by the adrenal medulla section of the adrenal gland and released primarily in response to hypoglycemia; it is also produced as a synthetic drug. A powerful vasopressor substance, epinephrine acts to increase blood pressure and stimulate the heart muscle, accelerating the heart rate and increasing cardiac output.

EPIRB

Emergency Position Indicating Radio Beacon

Epithelial

An epithelial tissue is a tissue that covers the external surface of the body and lines hollow structures inside the body.

EPO

Element Project Office

EPO

Experiment Planning Officer

EPOC

External Payload Operations Center

EPP

Experiment Preparation Program

EPROM

Erasable Programmable Read Only Memory

EPS

Electrical Power System

EPSP

Experiment Power Switching Panel

Epstein-Barr virus

The Epstein-Barr virus is a herpesvirus that causes infectious mononucleosis (mono). It is also found in cell cultures of Burkitt’s lymphoma and is associated with nasopharyngeal carcinoma.

Equilibrium

Equilibrium is a state of balance, a condition in which the contending forces are equal.

EQUIP

Equipment

Early Release

ERA

Exobiology and Radiation Assembly

ERAN

Early Release Alteration Notice

ERBE

Earth Radiation Budget Experiment

ERD

Experiment Requirements Document

EREP

Earth Resources Experiment Package

Ergometer

An ergometer is a rotary pedal device (i.e., static exercise bicycle) that provides a calibrated, or specific, resistance. The force required to overcome the resistance is measured as work.

Ergometry

Ergometry is the study of physical work activity, including work performed by specific muscles or muscle groups. The study may involve testing with equipment, such as stationary bicycles, treadmills, or rowing machines.

ERT

Experiment Review Team

ERTS

Earth Resources Technology Satellite

Erythrocyte

An erythrocyte is more commonly known as a red blood cell, which is the most numerous type of blood cell. Erythrocytes contain the red pigment hemoglobin and are responsible for oxygen transport. In humans, the number of erythrocytes in the blood varies between 4.5 and 5.5 million per cubic millimeter. They survive for about four months and are then destroyed in the spleen and liver.

Erythrokinetics

Erythrokinetics is a quantitative, dynamic study of in vivo (occurring within the body) production and destruction of erythrocytes (red blood cells).

Erythron

Erythron is an element of the blood-forming system of the body that is involved in the production of red blood cells; it is not a single organ but is dispersed throughout the blood-forming tissue of the bone marrow.

Erythropoiesis

Erythropoiesis is the process of red blood cell production, which normally occurs in the blood-forming tissue of the bone marrow.

Erythropoietin

Erythropoietin is a hormone secreted by certain cells in the kidney in response to a reduction in the amount of oxygen reaching the tissues; it stimulates red blood cell production.

ESD

Electrostatic Discharge

ESFS

Experiment Simulation Flight Software

ESI

Electrical System Integration

ESI

Experiment Support Item

ESOP

Experiment System for Orbiting Primate

ESP

Experiment Switching Panel

ESR

Engineering Support Agency

ESRD

Experiment Simulator Requirements Document

ESS

Experiment Schedule Service (database)

ESS

Energy Storage Subsystem

ESS

Experiment Support Scientist

Est

Estimate

EST

Eastern Standard Time

ESTEC

European Space Research & Technology Center

Esterase

Esterase is a generic term for enzymes that catalyze the hydrolysis of esters.

ESU

Experiment Checkout Unit

External Tank

ETA

Expected Time of Arrival

Ethanol

Ethanol is a clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is also widely used as a solvent and preservative in pharmaceutical preparations, as well as serving as the primary ingredient in alcoholic beverages.

Ethylene glycol

Ethylene glycol is a compound containing two hydroxy groups bound to adjacent carbon atoms; it is the simplest glycol and has the molecular formula HOCH₂CH₂OH. Ethylene glycol is used in antifreeze and other products.

Ethylenediaminetetraacetic acid (EDTA)

Ethylenediaminetetraacetic acid (EDTA) is a chelating agent, generally used in the form of a sodium salt. In biochemical research, it is used to remove Mg2+, Fe2+, etc. from reactions affected by such ions. It is also used as a water softener, an anticoagulant, and a stabilizing agent for drugs that decompose rapidly in the presence of traces of metal ions . EDTA is also used to treat lead poisoning.

Etiocholanolone

Etiocholanolone is a metabolite of adrenocortical and testicular hormones and is an important 17-ketosteroid. It produces fever when given to humans.

Etiology

Etiology refers to the study of all factors that may be involved in the development of a disease, including susceptibility of the patient, the nature of the disease agent, and the way in which the patient's body is invaded by the agent.

ETO

Estimated Time of Operation

ETR

Eastern Test Range

Electrophoresis Unit

EUE

Experiment Unique Equipment

EUH

Experiment Unique Hardware

EURECA

European Retrievable Carrier

European Space Agency (ESA)

The European Space Agency (ESA) sponsors space research and technology among 13 member states (Austria, Belgium, Denmark, France, Germany, Ireland, Italy, The Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom), one associate member (Finland), and one country under cooperative agreement (Canada). The agency is headquartered in Paris, France.

EUS

Equipment Unique Stowage

Eustachian tube

The eustachian tube is a tube, lined with mucous membrane, that joins the nasopharynx and the middle ear, allowing equalization of the air pressure in the middle ear with atmospheric pressure.

EUV

Extreme Ultraviolet

Evacuate

Evacuate means to empty or remove the contents.

EVAL

Earth-Viewing Application Laboratory

EVAS

Extravehicular Activity System

EVS

Equipment Visibility System

EVT

Experiment Verification Test

Experimenter

Explosive

Exam

Examination

EXC

Experiment Computer

EXCB

Experiment Connector Bracket

Excitability

In neurophysiology, excitability refers to the triggering of a conducted impulse in the membrane of a muscle cell or nerve fiber. During excitation, a polarized membrane becomes momentarily depolarized and an action potential is set up.

Excreta

Excreta is waste matter eliminated or separated from an organism.

Excretion

Excretion is the transport and expulsion of waste products such as urine or carbon dioxide. It also refers to the release of hormones or protein products from cells or tissues.

Excretory

Excretory describes the act or process of eliminating metabolic waste products from the body.

Exercise capacity

Exercise capacity is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.

Exocrine

Exocrine glands discharge secretions by means of a duct, which opens onto an epithelial surface (a tissue that covers the external surface of the body and lines hollow structures inside the body).

EXP

Experiment

Expired gas pressure

Expired gas pressure is positive pressure in the alveoli (air sacs) of the lungs. This positive pressure allows air to be exhaled.

Extended Duration Orbiter Medical Project (EDOMP)

The Extended Duration Orbiter Medical Project (EDOMP) was conducted from 1989 to 1996 to address concerns about the physiologic condition of Shuttle astronauts on missions up to 16 days in duration. Before this project began, the Shuttle had not flown longer than 10 days. Space travelers may faint when they stand up (orthostatic intolerance) after all but the shortest flights, and their muscle strength may be reduced. The program focused on ensuring that the crew could land the Orbiter and exit from it without help after a 16-day flight. Astronauts on 40 Shuttle flights (STS-32 through STS-72) participated in 36 EDOMP investigations. The results of these investigations were used to make rules and recommendations for 16-day flights. Several types of exercise devices (i.e. a treadmill, a cycle ergometer, and a rower) were among the devices and procedures developed to prevent the deconditioning of the body that occurs during space flight. The crew transport vehicles, in which astronauts are now transported after landing, were built to enhance medical capabilities at the landing site as well as crew comfort and safety. A database, 125 formal publications, and 299 abstracts, technical papers, and presentations have also resulted from the EDOMP.

Extensor

An extensor is a type of muscle which works to straighten a limb, the antagonist of a flexor.

Extensor Digitorum Longus

The extensor digitorum longus is a superficial muscle of the lower leg which allows one to extend the foot.

Extracellular fluid

Extracellular fluid is the fluid which is inside the body, but outside the cells that are within the body.

Extracellular fluid volume

Extracellular fluid volume is the volume of the fluid external to the body's cells.

Extravehicular Activity (EVA)

An extravehicular activity, or EVA, is any activity that occurs external to the spacecraft requiring the crewmember to wear a life support suit.

Exudative

Exudative refers to a substance that may ooze or pass gradually out of a body structure or tissue. Specifically, this refers to a fluid or semisolid which may become encrusted or infected because of injury or inflammation.

Eye grounds

The eye grounds is the fundus of the eye, the fundus being the base or the deepest part of an organ or the portion farthest from the mouth of an organ.

Fahrenheit Degrees

Formatted

Forward End Cone

FAA

Federal Aviation Administration

Fab

Fabrication

Fac

Facility

FACI

First Article Configuration Inspection

Factor D

Factor D is an enzyme important in the activation of the complement system. This complicated system of enzymes protects humans by killing microorganisms and infected cells.

FAME

Franco-American Macaque Experiment

FAO

Flight Activity Officer

FAR

Flight Acceptance Review

FAS

Federation of American Societies

FASEB

Federation of American Societies for Experimental Biology

Fast myosin

Myosin is the most abundant protein in muscle fibrils, having the important properties of elasticity and contractility. Together with another protein called actin, it comprises the principal element which allows muscles to contract. Fast myosin refers to myosin found in fast-twitch muscle fibers, which are adapted for very rapid and very powerful muscle contractions, such as for jumping or for short-distance powerful running.

Fast-twitch

Fast-twitch describes a muscle fiber that contracts quickly, especially during brief high-intensity physical activity requiring strength.

Fast-twitch fiber

A fast-twitch fiber is a muscle fiber that produces force for rapid movement and exercise, such as for jumping or full-speed running for a short distance. These fibers use no oxygen for energy, thus are called anaerobic.

Fast-twitch muscle fiber

Fast muscle fibers have much larger fibers than slow muscle fibers for greater strength of contraction; they are adapted for very rapid and very powerful muscle contractions, such as for jumping or for short-distance powerful running.

Fatigability

Fatigability is a measure of the rate at which fatigue is induced.

Fatigue

Fatigue means mental or physical tiredness, usually caused by prolonged or intense activity, but also possibly caused by disease, lack of adequate nutrition or other anomalous factors.

Fatigue Test

A fatigue test is a test which determines how much work/activity can be accomplished by different muscles before their efficiency is reduced.

FATR

Flight Acceptance Test Review

FAUST

Far Ultraviolet Astronomy

FBC

Fill & Bleed Cart

Flight Control

FCD

Flight Control Division

FCE

Flight Crew Equipment

FCOS

Flight Computer Operating System

FCR

Flight Control Room

FCT

Flight Control Team

Facility Developer

Flight Director

Flight Day

FDD

Flight Definition Document

FDF

Flight Data File

FDM

Flight Data Manager

FDOR

Final Design and Operations Review

FDR

Final Design Review

FDS

Flight Design and Schedule

Facilities Engineer

FED

Federal

FEDP

Facilities and Equipment Design Plan

FEDWG

Flight Experiment Data Working Group

FEE

Frog Embryology Experiment

FEL

First Element Launch

Femur

The femur, also called the thigh bone, is the long bone between the hip and the knee.

FEP

Fluorinated Ethylene Propylene

FEP

Front End Processor

FERD

Facility and Equipment Requirements Document

Ferment

In bacteriology, ferment means the anaerobic dissimilation of substrates with the production of energy and reduced compounds. The mechanism of fermentation does not involve a respiratory chain or cytochrome, hence oxygen is not the final electron acceptor as in oxidation.

Ferric

Ferric is iron with a valence of three.

Ferritin

Ferritin is an iron-protein complex and is one of the forms in which iron is stored in the tissues of the intestine, spleen, and liver.

Ferrous

Ferrous is iron with a valence of two.

FES

Fluids Experiment System

FEU

Frog Embryology Unit

Flexible Input

Fibrinogen

Fibrinogen is a substance present in blood plasma that causes blood coagulation.

Ficoll-Hypaque technique

The Ficoll-Hypaque technique is a density gradient centrifugation test for separating lymphocytes from other formed elements in blood; the sample is layered onto a Ficoll-sodium metrizoate gradient of specific density; following centrifugation, lymphocytes are collected from the plasma-Ficoll interface.

Fiducial

Fiducial means regarded or employed as a standard of reference

FIFO

First In First Out

Filamentous

Filamentous means composed of filaments or threadlike structures.

FILO

First In Last Out

Finger cot

A finger cot is a latex sheath for the finger.

Finger pulse volume

Finger pulse volume is a measure of variations in the size of the finger resulting from changes in the amount of blood present.

Firing frequency

Firing frequency is the rate (or frequency) of the excitation of nerve or muscle fibers (called firing).

Fissure

A fissure is a crack-like lesion or wound of the skin.

Fixative

A fixative is a chemical which renders a cell or organism suspended or preserved in a stable state, usually so that it can be studied at a later date. For instance, a fixative might be used to preserve a tiny organism on a microscope slide.

Fixed

The term "fixed" refers to a chemical treatment of tissue or cells that results in preservation.

Flammable Liquid

Flammability

Flammability is the ability of a substance to have a combustion reaction; often determined flash point which is the lowest temperature at which a substance will ignite when exposed to a flame.

FLAP

Flight Application Software Packages

FLAP

Spacelab Flight Application Software

Flash frozen

Flash frozen means the process of freezing multiple solutions with liquid nitrogen to prevent diffusion between them until they are allowed to thaw.

Flatulence

Flatulence is the presence of an excessive amount of air or gas in the stomach and intestinal tract, causing distension of the organs and in some cases, mild to moderate pain.

Flavobacterium

Flavobacterium is a genus of aerobic to facultatively anaerobic, nonsporeforming, motile and nonmotile bacteria (family Achromobacteraceae) containing Gram-negative rods; motile cells are peritrichous. These organisms characteristically produce yellow, orange, red, or yellow-brown pigments. They are found in soil and fresh and salt water. Some species are pathogenic.

FLEX IN

Flexible Input

Flexor

A flexor is a type of muscle which works to flex a limb (or bend towards the body); and is the opposite of an extensor, which pulls a limb away from the body.

Flora

Flora are microorganisms that live on or within a body to compete with disease-producing microorganisms and provide a natural immunity against certain infections.

Floral initiation

Floral initiation is the first stage of flower production.

Floret

A floret is a small flower or cluster of flower buds, such as in a head of cauliflower.

Flow cytometer

A flow cytometer is a device used to perform flow cytometry. Flow cytometry is a method of measuring fluorescence from stained cells that are in suspension and flowing one at a time through the point of focus of one or two lasers, which activate the dyes. Flow cytometry is used to measure cell size, number, viability and nucleic acid content with the aid of acridine orange, Kasten's fluorescent Feulgen stain, ethidium bromide, trypan blue and other selective staining agents.

Flow cytometry

Flow cytometry is a method used to count cells (especially blood cells), using a glass chamber of known volume.

FLT

Flight

Fludrocortisone

Fludrocortisone is a synthetic steroid medication used in replacement therapy when a patient's adrenal cortex does not produce normal amounts of hormones.

Fluence

Fluence refers to the ease with which particles flow.

Fluid balance

Fluid balance is the relationship between fluid intake and fluid output. A negative fluid balance indicates that more fluid was put out than taken in during a given time period; a positive fluid balance indicates the opposite.

Fluid loading

Fluid loading is the ingestion of unusually large amounts of fluid, usually with the intention of increasing plasma volume.

Fluid physics

Fluid physics is the science of phenomena observed in fluids, and the behavior of fluids in different conditions. For example, thermic convection influences the behavior of fluids. In microgravity, thermic convection does not exist and other phenomena such as Marangoni convection (which is overlayed by thermic convection on Earth) can be observed and studied.

Fluid shift

Fluid shift refers to the shift of fluids from the lower to the upper body upon exposure to or recovery from microgravity. This phenomenon also occurs to a lesser extent during bed rest or exposure to lower body negative pressure. It may also refer to fluid transfer between intracellular and extracellular compartments.

Fluorescence microscopy

Fluorescence microscopy is the use of a light microscope that uses fluorescent light to analyze specimens.

Fluorescent bone marker

A fluorescent bone marker is a chemical marker that binds to cell constituents. Its presence is noted microscopically by the emitted fluorescence when certain types of light traverse the thin section of tissue.

Fluorometric

A fluorometer is an instrument used to measure the intensity of radiation.

Flux

Flux can be defined as a continuous movement, or the rate of flow of particles or energy. It also refers to a quantity expressing the strength of a force field in a given area.

Frequency Modulation

FMEA

Failure Mode Effects Analysis

FMECA

Failure Mode Effects and Criticality Analysis

FMR

Ferromagnetic Resonance

FMR

Finance Management Report

FMS

Fluid Management System

Functional Objective

FOB

Freight on Board

FOC

Full Operational Capability

FOD

Flight Operations Directorate

Folic acid

Folic acid is a yellow, crystalline, water-soluble vitamin of the B compex group essential for cell growth and reproduction.

Fomite

Fomite is a non-living material, such as bed linen, which may convey pathogenic organisms.

FOR

Final Operations Review

Force

A force is the manifestation of the action of one body upon another. Forces arise from the action of two bodies in contact with one another.

Force transducer

A force transducer is a device that converts force to another form of energy, such as an electical signal.

Forced Expiratory Flow

Forced expiratory flow is measured by a simple pulmonary test; in performing the test the person first takes as deep a breath as possible, then exhales as rapidly and as completely as possible into a machine known as a spirometer, which measures the amount of air inhaled or exhaled.

Forced Expiratory Volume

The forced expiratory volume is the volume of air resulting from the forced expiratory flow test in which a person first inspires maximally to the total lung capacity, then exhales as rapidly and as completely as possible.

Forced Vital Capacity (FVC)

Forced Vital Capacity (FVC) is the volume of air resulting from the forced expiratory flow test in which a person first inspires maximally to the total lung capacity, then exhales as rapidly and as completely as possible.

Forcing function

A forcing function is used to excite a system so that the systems responses can be measured.

Formaldehyde

Formaldehyde is a pungent gas; in liquid form, it is used as an antiseptic, disinfectant and fixative for tissues.

Formalin

Formalin is a 37% aqueous solution of formaldehyde, used as a histologic fixative.

FOS

Flight Operations Support (Personnel)

Fourier analysis

Fourier analysis is a method of converting a function of time or space into a function of frequency; it is used in the reconstruction of images derived from computed tomography and magnetic resonance imaging in radiology and in analysis of any kind of signal for its frequency content.

FOV

Field of View

Fovea

The fovea is the part of the retina in which vision is sharpest. It is a slight depression or pit at the back of the retina near the optic nerve.

FPI

Flight Payloads Integration

FPM

Flight Project Manager

FPM

Fluid Physics Module

FPS

Flight Propulsion System

fps

Feet per Second

FPV

Flow Proportioning Value

Failure Report

Frame

Functional Requirements

Fractionation

Fractionation means to separate components of a mixture.

Frame of reference

A frame of reference is used by the Central Nervous System of humans and most animals to orient the body in different situations. The reference for the vestibular organ is the gravitational force, which pulls everything on Earth downwards (to the center of the Earth) with the force of 1g.

FRB

Failure Review Board

FRD

Failure Requirements Document

FRD

Functional Requirements Document

Freons

Freons are a group of halogenated hydrocarbons, usually based on methane, containing one or more fluorine and/or other halogen atoms. Freons are commonly used as refrigerants and propellants for aerosols.

Frequency

Frequency is the number of times a phenomenon occurs within a specified interval such as the number of repetitions per unit time of a complete waveform.

FRR

Flight Readiness Review

FRVR

Flight Readiness Verification Review

Factor of Safety

Frequency Scatterometer

Flammable Solid

FSCM

Federal Supply Code for Manufacturers

FSE

Flight Support Equipment

FSK

Frequency Shift Keyed

FSN

Federal Stock Number

FSO

Functional Supplemental Objective

FSP

Flight Support Plan

FSS

Fire Suppression System

FSS

Flight Support Structure

FSSR

Functional Subsystem Software Requirements

FST

Flight Support Team

FST

Functional System Test

Foot

FTMS

Fluid Transfer Management System

FTS

Federal Telecommunications System

FTS

Flight Telerobotic Servicer

FUNC

Functional

Functional residual capacity

The functional residual capacity is the amount of air remaining in the lungs at the end of normal expiration (about 2300 ml).

Fungi

Fungi are any of a large group of plants which do not contain chlorophyll, including the yeasts, molds, and mushrooms.

FUO

Follow-up Output

Furunculosis

Furunculosis is a condition marked by the presence of localized pyogenic infection originating in the hair follicle.

FUSE

Far Ultraviolet Spectroscopy Explorer

Fusobacterium

Fusobacterium is a genus of bacteria (family Bacteroidaceae) containing Gram-negative, nonsporeforming, obligately anaerobic rods, which produce butyric acid as a major metabolic product. Fusobacteria may be nonmotile or motile. Motile cells are peritrichous. These organisms are found in the cavities of man and other animals; some species are pathogenic

FVT

Flight Verification Test

Fiscal Week

FWD

Forward

FWHM

Full Width, Half Maximum

FWSS

Flight Waste Stowage System

FWW

Food, Water and Waste Management

Fiscal Year

FY 80

Fiscal Year 1980

Acceleration of Gravity

Grams

Ground-Shield Pin Number

G&A

General and Administrative

G-A

Ground-to-Air

G-jitter

G-jitter is fluctuation in acceleration forces acting on a spacecraft in orbit.

G-suit

A G-suit is a garment worn by space travelers during launch and/or landing. It exerts pressure, usually by means of inflatable air bladders, on the thighs and abdomen to lessen the pooling of blood in the lower part of the body during acceleration.

GaAs

Gallium Arsenide

Gait

Gait is a manner of walking.

Galactic cosmic rays

Galactic cosmic rays are the highest energy charged particle radiation to reach Earth. They originate from sources outside the the solar system and are distributed throughout the Milky Way galaxy. They travel at nearly the speed of light striking Earth from all directions.

Galactic radiation

Galactic radiation is energetic particles from distant stars and galaxies.

Galley

A galley is the kitchen of a ship or aircraft.

Galvanometer

A galvanometer is an instrument used to measure the intensity of an electric current, usually by the deflection of a magnetic needle.

Gamma radiation

Gamma radiation is electromagnetic radiation of shorter wavelength and higher energy than X-rays. Gamma rays have greater penetration than X-rays and are harmful to living tissues. Carefully controlled doses are used in radiotherapy.

Gamma ray

A gamma ray is a photon emitted spontaneously by a radioactive substance.

Gamma-aminobutyric acid (GABA)

Gamma-aminobutyric acid (GABA) is an acid found in the central nervous system -- predominantly in the brain -- where it acts as an inhibitor of nerve impulses.

GAMS

Gas Analysis Measuring System

Ganglia

Ganglia are any structures containing a collection of nerve cell bodies.

Ganglion

A ganglion is any structure containing a collection of nerve cell bodies in the central or peripheral nervous system.

Gargle

Gargle means to rinse the space between the cavity of the mouth and the pharynx by taking fluid in the mouth and forcing the expired breath through it while the head is held far back. Gargle can also mean a medicated fluid used wash the throat.

GAS

Gas Analyzer Spectrometer

GAS

Get Away Special

GAS

Ground Application Software

Gas chromatography

Gas chromatography is the process of separation and analysis of different substances according to their different attraction to a standard absorbent substance.

Gas exchange

Gas exchange is the exchange of carbon dioxide for oxygen.

Gas exchange ratio

The gas exchange ratio (respiratory exchange ratio, R) is the ratio of carbon dioxide output to oxygen intake. The value changes under different metabolic conditions, but the average value is considered to be 0.825.

Gas liquid chromatography (GLC)

Gas liquid chromatography utilizes the same method of separation as gas chromatography, except the stationary phase is liquid rather than solid.

Gastric acid

Gastric acid is the liquid secreted by the gastric glands of the stomach; its main digestive constituents are hydrochloric acid, mucin, renin and pepsinogen. The acid acts to aid in digesting food and killing unwanted bacteria and organisms that have been ingested with food.

Gastric emptying

Gastric emptying is emptying of the stomach into the small intestine for the next step in digestion.

Gastrocnemius

The gastrocnemius is a muscle that forms the greater part of the calf of the leg; it flexes the knee and foot so that the toes point downward.

Gastrocnemius medialis

The gastrocnemius medialis is the section of the gastrocnemius muscle that forms the greater part of the calf of the leg.

Gastrocnemius soleus

The gastrocnemius soleus are the major muscles of the calf.

Gastroenteritis

Gastroenteritis is the inflammation of the mucous membranes that line the stomach and intestine.

Gastrointestinal

Gastrointestinal refers to the stomach and intestines.

Gastrointestinal motility

Gastrointestinal motility is the contraction of the smooth muscle layers of the gastrointestinal tract to move food through the tract during digestion.

Gastrointestinal physiology

Gastrointestional physiology is the study of the function of the stomach and intestines.

Gauer-Henry reflex

The Gauer-Henry reflex can be described as follows: the headward shift of fluids seen in space flight is thought to produce a transient increase in central blood volume; the transient increase is detected by stretch receptors in the heart and interpreted as an increase in total blood volume. A compensatory loss of water and sodium is then thought to be effected by a series of neural, humoral and direct hydraulic mechanisms.

Gavage

Gavage is a type of exposure in which a substance is administered to an animal (or human) through a stomach tube.

Gaze

Gaze is the act of looking steadily at an object.

Gigabyte

Ground Based

GBDS

Ground Based Development System

GBT

Ground Based Test

GCC

Ground Cooling Cart

GCMA

Gas Control Measuring System

GCOS

Ground Computer Operating System

General Dynamics

GDMS

Ground Data Management System

GDP

Generalized Document Processor

GDP Mannose Mannosyl Hydrolase

GDP Mannose Mannosyl Hydrolase is the protein responsible for the incorporation of carbohydrates into bacterial cell walls. Understanding its structure and function will help control entero-pathogenic bacteria which cause food poisoning.

GDS

Ground Data System

GDSD

Ground Data Systems Division

Gel electrophoresis

Gel electrophoresis is the process of separating a mixture of molecules in a gel media by the application of an electric field. In general, molecules with similar electric charges and density will migrate at the same rate together in the gel.

GEMS

The Gas Exchange Measurement System,or GEMS, is a unit consisting of two Gas Analyzer Systems that measures the CO2 and H2O vapor going into and leaving the leaf chamber.

Gene

The gene is the functional unit of heredity which occupies a specific place on a chromosome.

Gene expression

Gene expression refers to the transcription and translation of a specific part of the DNA code with the ultimate outcome being protein synthesis.

Gene regulation

Gene regulation is the control of gene transcription by chemical factors that regulate the RNA polymerase binding to DNA.

Gene transcription

Gene transcription is the process of constructing a messenger RNA molecule using a DNA molecule as a template, with resulting transfer of genetic information to the messenger RNA.

Genera

Genera is a subdivision of a family of animals, plants or microorganisms. A genus (plural) is usually composed of several closely related species, but the genus Homo has only one species, humans (Homo sapiens).

Genetic

Genetic refers to genetics, which is a branch of science concerned with heredity.

Genetic program

The genetic program, also called the genetic code, is the information carried by the genes (DNA and RNA) and determines how an organism develops, including its appearance, function, and instincts.

Genomic

Genomic means relating to the genome, the genetic material of an organism.

GEO

Geosynchronous Earth Orbit

Geomagnetic

Geomagnetic means pertaining to the earth's magnetic field.

Geophysics

Geophysics is the study of Earth physics including the fields of meteorology, hydrology, oceanography, seismology, volcanology, magnetism, radioactivity and geodesy.

GEOSAR

Geosynchronous Earth Orbit Synthetic Aperture Radar

Geosynchronous

Geosynchronous refers to a special type of orbit around the Earth, where an object orbits the Earth in the same direction and at the same speed as the Earth's own rotation. This results in the orbiting object remaining in a fixed position above a geographic point on the surface of the Earth. Telecommunications satellites are often put into geosynchronous orbit so that they may be accessible via radio waves from one area of Earth at all times.

Geotrichum candidum

Geotrichum candidum is a fungus that may cause lesions in the pulmonary and alimentary tracts of humans; however, these lesions may be secondary to an underlying unrelated condition.

German Aerospace Research Establishment (DLR, DFVL

German Aerospace Research Establishment (DFVLR-Deutsche Forschungsanstalt fur Luft- und Raumfahrt) is responsible for basic research in the German space program, as well as management, operations and general support of all German sponsored space activities. DFVLR was renamed DLR in 1989. The agency is headquartered in Cologne, with other centers in Berlin, Göttingen Braunschweig, Stuttgart, Oberpfaffenhofen (Munich).

Germination

Germination is the process of beginning to grow or develop.

GET

Ground Elapsed Time

GFE

Government Furnished Equipment

GFFC

Geophysical Fluid Flow Cell

GFP

Government Furnished Property

GGT

Gamma-glutamyl transferase, gamma-glutamyl transpeptidase

GH2

Gaseous Hydrogen

GHe

Gaseous Helium

GHF

Gradient Heating Facility

Giddy

Giddy means having a reeling, lightheaded sensation; dizzy.

Giemsa chromosome banding (G-banding)

Giemsa chromosome banding (G-banding) is a unique chromosome staining technique used in human cytogenetics to identify individual chromosomes, which produces characteristic bands.

Giemsa staining

Giemsa staining is a unique chromosome staining technique used to identify individual chromosomes, in which characteristic bands are produced. It is also known as G-banding.

Gingival

Gingival means relating to the gums.

Gingival sulcus

Gingival sulcus, also called the gingival crevice, is the space between the surface of the tooth and the free gingiva, or gum.

GIRD

Ground Integration Requirements Document

Girth

Girth is the distance around an object; circumference.

Glia

Glia refers to glial cells or neuroglia, the special connective tissue of the central nervous system.

Glial

Glial refers to glia or neuroglia, the special connective tissue of the central nervous system.

Globus pallidus

The globus pallidus is a structure in the brain involved in the regulation of voluntary movements at a subconscious level.

Glomerular Filtration Rate (GFR)

The glomerular filtration rate (GFR) is the amount of glomerular filtrate (a substance which is the same as plasma except that it has no significant amount of proteins) that is formed each minute in all nephrons of both kidneys. The GFR is normally about 125 ml/minute.

Glovebox

A glovebox is a device used to isolate an area for work with potentially hazardous substances or materials that need to be free from direct contact with the outside environment for any reason. Most gloveboxes used during flight are small, tightly enclosed boxes with a glass panel for viewing and special airtight gloves that a person on the outside can use to manipulate objects inside.

Glucocorticoid

A glucocorticoid is a steroid hormone that predominantly affects the metabolism of carbohydrates and, to a lesser extent, fats and proteins. Glucocorticoids are made in the outside portion (the cortex) of the adrenal gland. Cortisol is the major natural glucocorticoid. The term glucocorticoid also applies to equivalent hormones synthesized in the laboratory.

Glucose

Glucose is a simple sugar found in certain foods, especially fruit, and is a major source of energy occurring in human and animal body fluids. The determination of blood glucose levels is an important diagnostic test in diabetes and other disorders.

Glucose-6-phosphate dehydrogenase

Glucose-6-phosphate dehydrogenase is an enzyme which participates in the formation of glucose from carbon dioxide as part of the process of photosynthesis.

Glutamate

Glutamate is a derivative of glutamic acid, an amino acid occurring in proteins.

Glutaminase

Glutaminase is an enzyme found in the kidney that catalyzes the breakdown of the amino acid glutamine to ammonia and glutamic acid. This breakdown is a stage in the production of urea, a major component of urine.

Glutaraldehyde

Glutaraldehyde is a compound used as a fixative for localization of enzyme activity; tissues fixed in glutaraldehyde may be stored for weeks or months before processing.

Glutathione (GTH)

Glutathione (GTH) is a tri-peptide composed of three amino acids: cysteine, glutamic acid and glycine. Glutathione and the enzymes it forms, such as GTH peroxidase, are essential to all life and are found in tissues of virtually all plants and animals. GTH is present in all human cells, with the highest levels found in the liver, the lenses of the eyes, pancreas, spleen and kidneys.

Glyceraldehyde phosphate dehydrogenase

Glyceraldehyde phosphate dehydrogenase is an enzyme found in cells that participates in the glucose metabolism by removing a hydrogen atom from glyceraldehyde phosphate, a glucose metabolite, and adding a phosphate group to form 1,3 bisphosphoglycerate.

Glycine

Glycine is an amino acid constituent of proteins in the human body.

Glycogen

Glycogen is a large, complex carbohydrate molecule produced from glucose in the liver and muscles when blood sugar levels are high. Glycogen is broken down into lactic acid when it is used as an energy source in the liver or muscles.

Glycolysis

Glycolysis is the process of transforming glucose into lactic acid in the muscles (or other tissues), for energy production when sufficient oxygen is not available in an emergency situation.

Glycolysis rate

Glycolysis rate is the rate of energy-yeilding conversion of D-glucose to lactic acid in various tissues, notably muscle, when sufficient oxygen is not available for respiration. Because molecular oxygen is not consumed in the process, it is frequently referred to as anaerobic glycolysis.

Glycolytic enzymes

Glycolytic enzymes are a part of the glycolytic pathway that act as a catalyst. They work in sequence to convert glucose to pyruvate which produces adenosine triphosphate (ATP), the energy carrier.

Glycosaminoglycan (GAG)

Glycosaminoglycan (GAG) is the polysaccharide unit that makes up proteoglycans, a molecule made of saccharides and proteins. GAGs are extracellular matrix molecules that help give tissues like cartilage their rigid structure.

Glycoside

Glycoside is any of several carbohydrates that yield a sugar and a non-sugar on hydrolysis. The plant digitalis purpurea yields a glycoside used in the treatment of heart disease.

Gram

GML

General Measurement Loop

GMP

Guanosine 5'-monophosphate (guanylic acid)

GMS

General Management System

GMT

Greenwich Mean Time

GN&C

Guidance, Navigation and Control

GN2

Gaseous Nitrogen

GN2 freezer

A GN2 freezer is a small storage canister which uses gaseous nitrogen to keep samples at or below freezing.

GND

Ground

GNP

Gross National Product

GO2

Gaseous Oxygen

GOAL

Ground Operations Aerospace Language

Golgi

The Golgi apparatus is a collection of vesicles and folded membranes in a cell, usually connected to the endoplasmic reticulum. It stores and later transports the proteins manufactured in the endoplasmic reticulum. Golgi cells are types of neurons (nerve cells) within the central nervous system.

GOR

Ground Operations Review

GOS

Ground Operating System

GOWG

Ground Operations Working Group

GPC

General Purpose Computer

GPGU

General Plant (Growth) Unit

GPM

Gallons per Minute

GPO

Government Printing Office

GPPF

Gravitational Plant Physiology Facility

GPS

Global Positioning System

GPTU

General Purpose Transfer Unit

GPWS

General Purpose Work Station

Growth

Grab Air Sampler

The Grab Air Sampler is a device which used to collect air samples. The device is evacuated thus causing air to be quickly sucked into the device once the valve is opened.

Grab Sample Container (GSC)

The Grab Sample Container (GSC) is a device used to collect air samples. The device is evacuated thus causing air to be quickly sucked into the device as the valve is opened.

Gram-negative

Gram-negative denotes a bacteria that stains pink when stained with Gram’s stain. This staining technique is useful in bacterial taxonomy and identification and to indicate fundamental differences in cell wall structure.

Gram-positive

Gram-positive denotes a bacteria that stains purple-black when stained with Gram’s crystal violet stain, usually indicating that the outer structure of the bacterium consists of a cytoplasmic membrane surrounded by a thick, rigid bacterial cell wall comprised of peptidoglycan. This staining technique is useful in bacterial taxonomy and identification, and to indicate fundamental differences in cell wall structure.

Gram’s stain

Gram’s stain is a method to differentially stain bacteria. Bacterial smears are fixed by flaming, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorized and then counterstained with safranin. Microorganisms are classified as either Gram-positive or Gram-negative.

Granulocyte

A granulocyte is a leukocyte, or white blood cell, characterized by the presence of cytoplasmic granules.

Granulocyte Colony Stimulating Factor

Granulocyte Colony Stimulating Factor is an immunoprotein produced by leukocytes during inflammation which functions to increase the proliferation of granulocytes in the bone marrow.

Granulocytosis

Granulocytosis is an increase in the total number of granulocytes, a type of leukocyte, in the blood.

Graviperception

Graviperception is the sense that gives knowledge of body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up." This perception in humans is provided by highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles that give the brain information about body position. Other organisms, like plants, also possess graviperception.

Gravireceptors

Gravireceptors are highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles, that give the brain information about body position, equilibrium, direction of gravitational forces, and the sensation of "up" or "down."

Gravisensitivity

Gravisensitivity is the sense of body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up." This sense in humans is provided by highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles that give the brain information about body position. Other organisms, like plants, also possess gravisensitivity.

Gravitational field

The gravitational field of the Earth is what pulls everything towards the center of our planet. Its force is defined as 1g (one "g" or one gravity). In comparison, the gravitational force present on the moon is 0.6 g’s, this weaker force allowed the astronauts to do their famous moon-jumps.

Gravitational loading

Gravitational loading refers to the application of force to a bone or part of the body. Under normal circumstances on Earth, gravity "loads" the bones and muscles with the force required to support the body.

Gravitoinertial environment

A gravitoinertial environment is an environment in which gravity and inertia exist.

Gravity gradient

A gravity gradient is a change in the gravitational force depending on the relative position to the Earth.

Gravity receptors

Gravity receptors, also known as gravireceptors, are highly specialized receptor organs and nerve endings in the inner ear, joints, tendons and muscles, that give the brain information about body position, equilibrium, direction of gravitational forces, and the sensation of "down" or "up."

GRD

Ground

GRMS

Acceleration Root Mean Square

GRO

Gamma Ray Observatory

Growth Hormone (GH)

Growth Hormone (GH), also called somatotropin, is a protein hormone of the anterior lobe of the pituitary. It is produced by the acidophil cells and it promotes body growth, fat mobilization, and inhibition of glucose utilization. It is diabetogenic when present in excess.

Growth medium

A growth medium contains nutrients and is a substance on or in which microorganisms or cells can be grown.

GSA

General Services Administration

GSE

Ground Support Equipment

GSFC

Goddard Space Flight Center

GSI

Government Source Inspection

GTOD

Greenwich True On Date

Guanylyl cyclase

Guanylyl cyclase is an enzyme that catalyzes the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP), a cyclic nucleotide that participates in intracellular signaling, from the substrate guanosine 5-triphosphate (GTP). There are two major classes of this enzyme, a soluble form and a transmembrane form. The catalytic activity of the soluble form is activated by the free radical nitric oxide (NO) when it complexes with the heme cofactor of the enzyme.

Gut wall

Gut wall refers to the wall of the intestine. It is here that most of the absorption of food from the digestive track into the body takes place.

GVPRD

Ground Verification Plan and Requirements Document

Gyroscope

A gyroscope is a rotating wheel, mounted in a ring or rings, for illustrating the dynamics of rotating bodies, the composition of rotations, etc. It can also be a form of the above apparatus, mounted so delicately as to render visible the rotation of the earth, through the tendency of the rotating wheel to preserve a constant plane of rotation, independently of the earth's motion.

Height

H/L

Hangar L

H/W

Hardware

H/X

Heat Exchanger

Hab

Habitation

Habitability

Habitability describes the capacity of a specific environment to maintain a certain quality of life. This term is often applied to the living resources and conditions of space vehicles.

Hair cell

Hair cells are sensory cells that react to mechanical stimuli and transmit information to the brain; they are the basic sensory unit of the inner ear.

HAL

Houston Aeronautic Language

HAL-S

Houston Aerospace Language Shuttle

HALOE

Halogen Occultation Experiment

Hamstring

A hamstring is any of the tendons at the back of the thigh; they attach the five hamstring muscles to their insertions on the bones of the lower leg.

Hand Grip Dynamometer (HGD)

The Hand Grip Dynamometer (HGD) is a device that measures the performance of the wrist flexor muscles. The subject has to actively push against a plate, thereby bending the wrist. At the same time, sensors inside the HGD measure the force applied.

Haptic

Haptic means referring to the sense of touch.

Haptoglobin

Haptoglobin is a protein present in blood serum that combines with hemoglobin to form a complex that is rapidly removed from the circulation by the liver.

Harvard step test

The Harvard step test is a type of cardiovascular endurance test that measures the ability to exercise continuously for extended periods without tiring. The subject steps up and down on a platform at a rate of 30 steps per minute for 5 minutes or until exhaustion. Exhaustion is the point at which the subject cannot maintain the stepping rate for 15 seconds. The subject immediately sits down on completion of the test, and the heart beats are counted after for 1 to 1.5, 2 to 2.5, and 3 to 3.5 minutes.

Harvest

Harvest means to gather (at maturity).

Harvestmen

Harvestmen are arachnids that resemble spiders but have a small rounded body and very long slender legs; also called “daddy longlegs."

HBC

Hyperbaric Chamber

HBR

High Bit Rate

HCG

Human Chorionic Gonadotropin

HDBK

Handbook

HDFDB

Hardware Development Facility Data Base

HDP1

Hardware Development Plan

HDRR

High Data Rate Recorder

Helium

Head-down tilt

Head down tilt is a laboratory procedure wherein a subject lies flat on his back on a tilted table so that the head is below the feet; it is used to cause a headward fluid shift. Prolonged bed rest with a slight head down tilt (usually with a 5-6 degree tilt from the horizontal) can reproduce some of the effects caused by exposure to microgravity.

Head-down tilt bed rest

Head-down-tilt bed rest is prolonged bed rest with a slight head-down-tilt (usually a 5-6 degree tilt from the horizontal). During head-down-tilt, the subject lies flat on his back on a tilted table so that the head rests below the feet, causing a headward fluid shift similar to the effect caused by exposure to microgravity.

Heart period

The heart period is the duration of one heart beat, also measured as the time between two heart contractions.

Heart rate

Heart rate is the number of heart beats per unit time, usually expressed as beats per minute.

Heat sink

A heat sink is a device which absorbs or removes heat from a thermal system.

Heavy ion

A heavy ion is an ion with mass greater than the normal mass for that element; an ion of a heavy isotope.

Heavy ion radiation

Outside Earth’s atmosphere, radiation from heavy ions, such as iron, exists. This kind of radiation is potentially more harmful than any other kind of radiation.

HED

High-Energy Deposition

HEFLEX

Helianthus Flight Experiment

HeG

Helium Glow

Helper T-cells

Helper T-cells are a type of white blood cell that contribute to (“help” with) the activation of the B-lymphocytes in the immunological process, thus helping to rid the body of foreign antigens.

Hematocrit

Hematocrit is the percentage of the volume of a blood sample occupied by cells, as determined by a centrifuge or device which separates the cells and other particulate elements of the blood from the plasma. The remaining fraction of the blood sample is called plasmocrit (blood plasma volume).

Hematologic

Hematologic means of or relating to hematology.

Hematological

Hematological means of or relating to blood or hematology.

Hematology

Hematology is the study of blood and blood forming tissues.

Hematopoiesis

Hematopoiesis is the formation of blood cells.

Heme

Heme is a subunit of the hemoglobin molecule that consists of an organic part and iron atom. The organic part is made up of four rings. The four rings are linked together to form a tetra structure. The iron atom is in the center of the four rings and binds to oxygen.

Hemin

Hemin is the chloride of heme in which the ferrous form of iron has become ferric (hematin is the hydroxide). Also termed hematin chloride; chlorohemin; ferriheme chloride; ferriprotoporphyrin; ferriporphyrin chloride; Teichman’s crystals; factor X for Haemophilus.

Hemoconcentration

Hemoconcentration is an increase in the proportion of red blood cells relative to the plasma, brought about by a decrease in the volume of plasma. Hemoconcentration may occur in any condition in which there is a severe loss of water from the body.

Hemocytometer

A hemocytometer is an apparatus used to estimate the number of blood cells in a quantitatively measured volume of blood.

Hemodilution

Hemodilution is an increase in plasma volume in relation to red blood cells; reduced concentration of red blood cells in the circulation.

Hemodynamic

Hemodynamic means of or relating to the physical dynamics of blood circulation.

Hemodynamics

Hemodynamics is the study of forces or mechanisms involved in blood circulation.

Hemoglobin

Hemoglobin is an iron-containing respiratory pigment contained within red blood cells; it gives the cells their red color. Hemoglobin, which has the unique property of combining reversibly with oxygen, picks up oxygen in the lungs and transports it to the rest of the body.

Hemoglobin-oxygen affinity

Hemoglobin-oxygen affinity reflects the binding strength or attraction of oxygen to hemoglobin.

Hemolysis

Hemolysis is the destruction of red blood cells with the release of hemoglobin into the surrounding fluid.

Hemolytic

Hemolytic refers to the destruction of red blood cells with the release of hemoglobin into the surrounding fluid.

Henry-Gauer response

The Henry-Gauer response is the inhibition of antidiuretic hormone secretion due to a rise in atrial pressure, which stimulates atrial stretch receptors.

HEPA

High Efficiency Particulate Air

Heparin

Heparin is a natural substance which inhibits blood clotting.

Heparinize

Heparinize means to treat with heparin to prevent clotting, as to heparinize blood.

Hepatic

Hepatic means relating to the liver.

Herpes simplex

Two types of herpes simples viruses exist: type 1 and type 2. Type 1 infections are marked by the eruption of one or more groups of vesicles on the vermilion border of the lips or at the external nares (fever blister or cold sore). Type 2 infections are characterized by such lesions on the genitalia. Both types commonly are recrudescent and reappear during other febrile illnesses or even physiologic states such as menstruation.

Herpesvirus

Herpesvirus is one of a group of DNA containing viruses causing latent infections in man and animals.

Herpetic

Herpetic means pertaining to, or of the nature of, herpes.

Heterotrophic plate count

Heterotrophic late count (HPC), formerly known as the standard plate count, is a procedure for estimating the number of live heterotrophic bacteria and measuring changes during water treatment and distribution in water or in swimming pools. Colonies may arise from pairs, chains, clusters, or single cells, all of which are included in the term "colony-forming units" (CFU).

Hexokinase (HK)

Hexokinase (HK) is an enzyme present in muscle and other tissues. It catalyzes the phosphorylation (adding a phosphor group) of glucose and other hexoses to form a hexose 6-phosphate.

High Frequency

HFSS

High Frequency Sounder System

Mercury

HgCdTe

Mercury Cadmium Tellurium

HGD

HI-REL

High Reliability

High-LET particles

Linear energy transfer (LET) refers to the measurement of the number of ionizations which radiation causes per unit distance as it traverses the living cell or tissue. The concept involves lateral damage along the path, in contrast to path length or penetration capability. Medical X-rays and most natural background radiation are low LET radiation, while alpha particles have high LET.

High-performance liquid chromatography

High-performance liquid chromatography (HPLC) is the separation and detection of nonvolatile chemicals (i.e., chemicals with boiling points greater than 200 to250 degrees Celsius) in a mixture. A sample amount, typically 10 to 20 microliters of liquid, is injected onto the chromatographic column. The column is packed with the stationary phase, a material with very specific properties that permit it to absorb or adsorb specific components of the sample under certain conditions. The mobile phase is constantly flowing through the column. When the sample is injected, it is swept onto the column by the mobile phase. Since all chemicals are different, they will have different affinities (attractions) to both the stationary phase and the mobile phase; this is called partitioning. Some components of the mixture will have a strong attraction to the stationary phase and pass through the column very slowly, while others will have less of an attraction and therefore pass more quickly through the column. Parameters are optimized so that the compounds in the sample elute (exit the column) individually. When the compounds elute, they must be detected (measured). This is done using a detector that is appropriate to the chemicals being measured.

HIRD

Hangar-L Interface Requirements Document

HIRIS

High Resolution Imaging Spectrometer

Histochemical

Histochemical refers to the study of intracellular distribution of chemicals, reaction sites, and enzymes.

Histochemistry

Histochemistry is the study of the identification and distribution of chemical compounds within and between cells, by means of stains, indicators, and light and electron microscopy.

Histogram

A histogram is a form of statistical graph in which values are plotted in the form of rectangles on a chart; also known as a bar chart.

Histological

Histological refers to the science concerned the identification and distribution of chemical compounds within and between cells, by means of stains, indicators, and light and electron microscopy.

Histological examination

A histological examination is a method of studying the structure of tissues by means of special staining techniques combined with light and electron microscopy.

Histone octamer

Histones are the proteins associated with nucleic acids in the nuclei of plant and animal tissues. An octamer is an aggregate of eight particles attached together.

HIU

Hardware Interface Unit

HIV Capsid Protein

HIV Capsid Protein is a protein that makes up the outer shell, surrounding the genetic material, of the AIDS virus. This protein is a target for drugs that can fight the AIDS virus.

HKG

Housekeeping

HMF

Health Maintenance Facility

HMFDB

Health Maintenance Facility Data Base

HMMR

High Resolution Multifrequency Microwave Radiometer

Hoffman reflex (H-reflex)

The Hoffman reflex (H-reflex) is a spinal reflex that can be modulated by a nerve pathway from the otolith receptors.

HOL

High Order Language

Homeostasis

Homeostasis is the physiological process by which the internal systems of the body (e.g. blood pressure, body temperature, acid-base balance) are maintained at equilibrium despite variations in the external conditions.

Homeostatic

Homeostatic means relating to homeostasis, which is the physiological process by which the internal systems of the body (e.g. blood pressure, body temperature, acid-base balance) are maintained at equilibrium despite variations in the external conditions.

Horizontality

Horizontality means situated near the horizon.

Hormonal

Hormonal means of or relating to hormones.

Hormone

A hormone is a substance produced in one part of the body; it passes into the bloodstream and is carried to other distant organs or tissues where it acts to modify their structure or function.

HOSC

Huntsville Operations Support Center

Housing

Housing is the type of cage used to contain animals during space flight.

High Pressure

HPA

High Power Amplifier

HPF

Hazardous Processing Facility

HPI

High Performance Insulation

Headquarters

HQTRS

Headquarters NASA

Heart Rate

High Rate

HR&T

Heat Rejection and Transport

HRDI

High Rate Demultiplexer Interface

HRDM

High Rate Demultiplexer

HRDW

Hardware

HRM

High Rate Multiplexer

HRMIS

High Rate Multiplexer Interface Simulator

HRMS

High Rate Multiplexer Simulator

HRP

Hardware Requirements Plan

HRPT

High Resolution Picture Transmission

hrs

Hours

HRSI

High Temperature Reusable Surface Insulation

HSAC

High Sensitivity Automatic Camera

HSO

Habitation/Station Operations

HST

Hubble Space Telescope

HTGPF

High Temperature General Purpose Furnace

HTM

High Throughout Mission

HTT

High Temperature Thermostat

Human factors

Human factors research is concerned with the interaction of humans with equipment, their environment, and each other to optimize the design of interactive workplaces for peak performance. In space flight, studying human factors has a special importance because of the time-critical interactions required between humans, machines and the environment.

Humerus

The humerus is the bone of the upper arm.

Humidity

Humidityis the amount of water vapor or moisture in the air.

Humoral

Humoral means circulating in the bloodstream.

Humoral immunity

Humoral immunity is the immediate response to an antigen which triggers antibody production. This is opposed to cell-mediated immunity, which involves white blood cells and is a delayed response to an antigen.

HVAC

Heating, Ventilating & Air Conditioning

HVC

High Voltage Converter

Hardware

Heat Exchanger

Hydration

Hydration is the chemical process in which water is taken into the body.

Hydrazine (N2H4)

Hydrazine is a chemical that, when mixed with an oxidizer, can be used as a monopropellant of satellites and the Space Shuttle once in orbit; it also fueled the first Titan rocket. Hydrazine derivatives are used in the manufacture of herbicides and fungicides, plant growth regulators, tranquilizers and tuberculosis drugs, and oxygen scavengers in boilers.

Hydrocarbon

A hydrocarbon is a compound containing only hydrogen and carbon.

Hydrogen

Hydrogen is a colorless, highly flammable gaseous element, the lightest of all gases and the most abundant element in the universe. As a component of water, hydrogen is crucial in the metabolic interaction of acids, bases, and salts within the body and in the fluid balance necessary for the body to survive.

Hydrology

Hydrology refers to the study of the distribution and circulation of water on land, in soil and rock and in the atmosphere.

Hydrostatic

Hydrostatic relates to the pressure of fluids or to their properties.

Hydrostatic gradient

A hydrostatic gradient is a change in the force, or pressure, of a fluid. The hydrostatic gradient in an adult standing upright and absolutely still is +90 mmHg between the veins of the feet and heart. This pressure difference is caused simply because of the weight of the blood in the veins between the heart and the feet.

Hydroxyapatite

Hydroxyapatite is the primary mineral component of bone. It has the chemical formula of 3Ca₃(PO₄)² and in crystal form is a hexagonal needle arranged in rosettes. It melts above 1100 degrees Celcius and cannot be dissolved in water.

Hydroxylysine

Hydroxylysine is one of the alpha amino acids.

Hydroxyproline

Hydroxyproline is a compound similar in structure to the amino acids and is found only in collagen.

Hygiene

Hygiene is the science or principles of health and the prevention of disease.

Hyper- and hypobaric physiology

Hyper- and hypobaric physiology is a discipline concerned with the study of ambient gases. Hyperbaric pertains to the pressure of ambient gases above 1 atmosphere, and hypobaric refers to the pressure of ambient gases below 1 atmosphere.

Hyperaldosteronism

Hyperaldosteronism is a disorder caused by overproduction of the adrenal hormone aldosterone, causing abnormalities in the sodium, water, and potassium levels in the body.

Hyperbolic

Hyperbolic describes a specific correlation/relationship of two variables to each other. When the first variable is zero, the second variable reaches its maximum; inversely, when the second variable is zero, the first variable is at its peak.

Hypercalcemia

Hypercalcemia is the presence of an abnormally high concentration of calcium in the blood.

Hypercalcinuria

Hypercalcinuria is the presence of an abnormally high concentration of calcium in the urine.

Hypercalciuria

Hypercalciuria is the presence of an abnormally high concentration of calcium in the urine.

Hypercalcuria

Hypercalcuria (or hypercalcinuria) is the presence of an abnormally high concentration of calcium in the urine.

Hypercapnic

Hypercapnic refers to the term hypercapnia, which describes an abnormally increased level of arterial carbon dioxide.

Hyperemic

Hyperemic refers to hyperemia, or the presence of an increased amount of blood in a body part or organ.

Hypergravity

Hypergravity means gravity forces higher than the "normal" Earth gravity.

Hyperosmolality

Hyperosmolality is the increased concentration of a solution expressed as osmoles of solute per kilogram of serum water.

Hyperosmotic

Hyperosmotic means having a concentration of osmotically active substances that is greater than the applicable standard.

Hyperoxaluria

Hyperoxaluria is an increased excretion of oxalate in the urine.

Hyperoxia

Hyperoxia is an increased concentration of oxygen in the tissues and organs.

Hyperoxic

Hyperoxic refers to an increased concentration of oxygen in the air or environment.

Hyperreflexia

Hyperreflexia is defined as lowering the response threshold consequent to electrical or mechanical stimuli applied at the muscle or the tendon, respectively. When the response threshold is lowered, the muscle will respond not only faster, but also to lower levels of stimuli.

Hypersecretory Gastric Syndrome

Hypersecretory Gastric Syndrome is the condition of abnormally increased secretion of gastric juices.

Hypertension

Hypertension is abnormally high arterial blood pressure.

Hypertext

Hypertext is text (appearing in electronic media) which is not constrained to be sequential; by using highlighted words and images, the user can access other web pages by clicking on the word or image, thus progressing through the information in a non-sequential manner.

Hypertonic

Hypertonic means having a higher concentration of osmotically active substances than the applicable standard (e.g., blood). A solution hypertonic to animal cells will cause a net flow of water across the cell membrane to the outside.

Hypertrophy

Hypertrophy is an increase in the size of a muscle or organ.

Hyperuricosuria

Hyperuricosuria is the increased excretion of uric acid in the urine.

Hyperventilation

Hyperventilation, or overventilation, is described by abnormally fast or deep respiration in which excessive quantities of air are taken in, causing buzzing in the ears, tingling in the extremities and sometimes fainting.

Hyphomycete

Hyphomycete is a class of fungi that produces asexual spores. They are widely distributed in soil and air.

Hypnotics

Hypnotics are a class of drugs often used as sedatives.

Hypocalcemia

Hypocalcemia is the presence of an abnormally low concentration of calcium in the urine.

Hypocalciuria

Hypocalciuria is the presence of an abnormally low concentration of calcium in the urine.

Hypocitraturia

Hypocitraturia is the decreased excretion of citrate in the urine.

Hypodermic syringe

A hypodermic syringe is a small syringe used with a hollow needle for injection or removal of fluids beneath the skin.

Hypokinesis

Hypokinesis is a condition of abnormally diminished motor activity.

Hyposecretory Gastric Syndrome

Hyposecretory Gastric Syndrome is the condition of diminished secretion of gastric juices.

Hypotension

Hypotension is a condition in which the arterial blood pressure is abnormally low. It occurs after excessive fluid loss or following severe blood loss from any cause.

Hypothalamus

The hypothalamus is the region of the brain which contains several important centers which control body temperature, thirst, hunger, water balance, and sexual function. It is also closely connected with emotional activity and sleep, and functions as a center for the integration of hormonal and autonomic nervous activity through its control of pituitary secretions.

Hypothesis

A hypothesis is an assumption not proved by experiment or observation that is made for the sake of testing its soundness.

Hypoventilation

Hypoventilation is reduced alveolar ventilation relative to metabolic production of carbon dioxide, so that alveolar carbon dioxide pressure increases above normal.

Hypovolemia

Hypovolemia (oligemia) is a decrease in the volume of circulating blood.

Hypoxemia

Hypoxemia is an abnormal deficiency of oxygen in the arterial blood.

Hypoxia

Hypoxia describes a state of below-normal levels of oxygen in the arterial blood or tissue. Six different kinds of hypoxia are defined by the various causes.

Hypoxic

Hypoxic refers to a decreased concentration of oxygen in the air or environment.

Hysteresis

Hysteresis is any situation in which the value of one variable depends upon whether the other has been increasing or decreasing.

Hertz

HZE particles

HZE, or high mass energy, particles are highly charged and energetic components of cosmic rays. These particles can deposit energy in tissue, possibly killing a cell if the particle passes to close to the cell’s nucleus.

Inspection

I-S

Interconnect Station

I/F

Interface

I/O

Input/Output

Integration Area

IACO

Integration, Assembly and Checkout

IAW

In Accordance With

IBCS

Inflight Blood Collection System

IBM

International Business Machines

Intercom

ICA

Intercom A

ICB

Intercom B

ICD

Interface Control Document

ICD

Interface Control Drawing

ICR

Interface Change Control Requirement

ICRP

International Commission for Radiation Protection

ICRS

Intercom Master Station

ICRS

Intercom Remote Station

ICS

Interpretive Computer Simulator

Identification

IDAPS

Image Data Processing System

IDE

Initial Design Evaluation

Idiopathic

Idiopathic denotes a disease of unknown cause.

IDL

Indentured Drawing List

IDS

Item Description Sheet

IECMU

Induced Environment Contamination Monitor Unit

IEEE

Institute of Electrical and Electronic Engineering

IERD

Integrated Experiment Requirements Document

Intermediate Frequency

IGES

Initial Graphic Exchange Specification

IGS

Investigator Ground Studies

IH/SR

Integrated Hardware/Software Review

IHF

Isothermal Heating Facility

IIA

Instrument Interface Agreement

Iliocostalis

The iliocostalis is the lateral division of the erector spinae, having three subdivisions: musculus iliocostalis lumborum, m. i. thoracis and m. i. cervicus.

ILS

Integrated Logistics System

ILSSE

Integrated Life Sciences Shuttle Experiments

IMBLMS

Integrated Medical and Behavioral Laboratory Measurement System

IMBP

Institute of Medico-Biological Problems

IMC

Image Motion Compensation

Immune cell

Immune cells attack unrecognized or foreign substances in the body in order to destroy harmful invaders and prevent infection and disease. See also B-cell or T-cell.

Immune system

The immune system provides the body with a defense against infection, afforded by the presence of circulating antibodies and white blood cells. Antibodies are manufactured specifically to deal with the antigens associated with different diseases as they are encountered, while white blood cells attack and destroy foreign particles in the blood and tissues, including antigen-antibody complexes.

Immunity

Immunity refers to the quality of being insusceptible to or unaffected by a particular disease or condition. Active immunity refers to a form of long-term, acquired immunity that protects the body against a new infection as a result of antibodies after an initial infection or artificially after immunization. Passive immunity refers to a form of immunity resulting from antibodies that are transmitted naturally through the placenta to a fetus or through the colostrum to an infant or artificially by injection of antiserum for treatment or prophylaxis. Passive immunity is not permanent and does not last as long as active immunity.

Immuno-hematology

Immuno-hematology is the study of antigen-antibody reactions and their effects on blood.

Immunocompetence

Immunocompetence pertains to the ability to produce a normal immune response.

Immunofluorescent antibody technique

The immunofluorescent antibody technique uses fluorescein-labeled antibodies to identify bacterial, viral or other antigenic material specific for the labeled antibody. Fluorescence microscopy is used to determine the specific binding of antibody through the production of a characteristic visible light that occurs upon application of ultraviolet rays to the preparation.

Immunoglobulin

An immunoglobulin is one of a class of structurally related proteins consisting of two pairs of polypeptide chains, one pair of light (L) low molecular weight chains and one pair of heavy (H) chains, all four linked together by disulfide bonds. On the basis of the structural and antigenic properties of the H chains, Ig’s are classified (in order of relative amounts present in normal human serum) as IgG, IgA, IgM, IgD and IgE. Antibodies are Ig’s, and all Ig’s probably function as antibodies.

Immunoglobulin A (IgA)

Immunoglobulin A (IgA) comprises about 10-15% of the body's total immunoglobulins. It is the major class of antibodies in external secretions, such as saliva, tears, breast milk, bronchial mucous and intestinal mucous. IgAs are secreted on the body’s surfaces as the first defense against bacterial and viral antigens thus preventing entry into the body. IgAs may be an important and effective antibody in areas other than mucosal tissues, such as the central nervous system.

Immunoglobulin D (IgD)

Immunoglobulin D is a blood protein characterized by it's unique heavy chain, the Delta class. IgD functions as an antibody and is found in the cell membrane of B lymphocytes.

Immunoglobulin E (IgE)

Immunoglobulin E is a blood protein characterized by it's unique heavy chain, the Epsilon class. IgE functions as a antibody and is found on the surface of basophils and mast cells. It is associated with allergic reactions.

Immunoglobulin G (IgG)

Immunoglobulin G (IgG), the most common type of antibody, comprises about 80% of the body's total immunoglobulins. It is the principal antibody in the serum and is produced in large quantities during secondary immune responses which, with IgM, activate the complement system. IgGs act on pathogens by agglutinating them, by opsonising them, by activating complement-mediated reactions against cellular pathogens and by neutralizing toxins.

Immunoglobulin M (IgM)

Immunoglobulin M (IgM) comprises 5-10% of the body's total immunoglobulins. It is the first antibody to appear in the serum after injection of an antigen and is produced during primary immune responses. It is capable of capturing and binding antigens to form large insoluble complexes which are readily cleared from the blood. IgM levels may be elevated in patients with delayed patterns of food allergy and manifest a protective defense response.

Immunohematologic

Immunohematologic refers to a branch of immunology that deals with the immunologic properties of blood.

Immunohistochemical

Interpersonal means being, relating to, or involving relations between persons.

Immunohistochemical

Immunohistochemical is the staining of tissues using monoclonal antibodies.

Immunological

Immunological relates to immunology, the study of the immune system. The immune system provides the body with a defense against infection via circulating antibodies and white blood cells. Antibodies are manufactured specifically to immediately deal with the antigens associated with different diseases as they are encountered, while white blood cells attack and destroy foreign particles in the blood and tissues.

Immunology

Immunology is the study of the immune system.

Immunophenotyping

Immunophenotyping is the recording of observable immunological characteristics of an individual, which result from interaction between the genes of that individual and the environment.

Immunoreactive

Immunoreactive is used to describe a situation where an antigen and antibody are reactive in vitro (occurring outside the body, traditionally in a test tube).

Immunoreactive growth hormone (IRGH)

Immunoreactive growth hormone (IRGH) is an interactive form of the growth hormone that also triggers immunoreactions (between antigen and antibody).

Impaction

Impaction means the effect of one thing on another.

Impactor

An impactor is a device that collects samples of particles suspended in air by directing a stream of the particle-containing air against a surface or into a liquid.

Impedance

Impedance is a measure of the total opposition to current flow in an alternating-current circuit.

Impinger

Impinger means to bear upon or put upon; a device that acts upon another (i.e. flames impinge on wood to make it burn).

Implantation

Implantation (nidation) is the attachment of the early embryo to the lining of the womb, usually six to eight days after ovulation. The site of implantation determines the position of the placenta.

Inch

Incompatibility Notice

In vitro

In vitro is a Latin term describing biological phenomena that are made to occur outside the living body (traditionally in a test tube).

In vivo

In vivo is a Latin term describing biological phenomena that occur,or are observed occurring, within the bodies of living organisms.

In-situ

In-situ is the Latin term for "in the original place".

Inclination

Inclination is the degree of deviation from a horizontal or vertical line. The inclination of the Space Shuttle as it orbits the Earth is tracked during missions, since its inclination determines the stability of the spacecraft . At some inclinations, the Shuttle is more stable than others, which means it requires less fuel to keep it in orbit and provides a better environment for some gravity-sensitive experiments.

INCO

Instrument and Communications

Incubate

To incubate is to artificially warm (and hatch eggs) by maintaining conditions similar to body heat.

Incubation period

An incubation period is the time between exposure to a pathogenic organism and the onset of the symptoms of a disease.

Incubator

An incubator is a device that maintains controlled environmental conditions, including proper oxygenation, humidity and temperature. Some incubators are specifically designed to cultivate cell and bacterial cultures, while others are designed to hatch eggs or protect infants (usually premature).

Inertia

Inertia is the tendency of a body to resist acceleration, or to resist motion, action or change.

Inertial Measurement Unit (IMU)

The Inertial Measurement Unit (IMU) is a Shuttle orbiter navigation system which provides attitude and velocity data to the Guidance, Navigation, and Control (GNC) system.

Inertial property of mass

The inertial property of mass states that matter will remain at rest or in uniform motion in the same straight line unless acted upon by an external force.

Infiltrates

Infiltrates are substances that seep through a filter.

Influent

Influent refers to something which flows in or into.

Influenza

Influenza is an acute infectious respiratory disease, in which the inhaled virus attacks the respiratory epithelial cells of susceptible persons and produces an inflammation of the mucous membrane.

Influenza virus

Influenza virus is of the genus Orthomyxoviridae, which comprises the influenza viruses types A and B. Each type of virus has a stable nucleoprotein group antigen common to all strains of the type, but distinct from that of the other type; each also has a mosaic of surface antigens (hemagglutinin and neuraminidase) which characterize the strains. Strain notations indicate (1) type, (2) geographic origin, (3) year of isolation and (4) in the case of type A strains, the characterizing subtypes of hemagglutinin and neuraminidase antigens (e.g., A/HongKong/1/68 (H3N2)).

Infrared

Infrared is the part of the invisible spectrum that is contiguous to the red end of the visible spectrum.

Infrared anatomical photography

Infrared anatomical photography is a type of photography that uses heat sensitive film to see the regions of the body that give off heat.

INGRES

INGRES is a relational database management system for the VAX (Variable Access Exchange)

Inguinal

Inguinal is relating to the groin.

Innate

Innate means possessed as an essential characteristic; inherent.

Inner Ear

The inner ear (or labyrinth) is a convoluted system of cavities and ducts comprising the organs of hearing and balance.

Inoculate

Inoculate is to introduce a substance (inoculum) into the body to produce or to increase immunity to the disease or condition associated with the substance.

INOP

Inoperative

Inorganic

Inorganic means of or originating from non-carbon based compounds.

Inotropic

Inotropic means influencing the contractility of muscle tissue.

INS

Integrated Nitrogen System

Insomnia

Insomnia is a prolonged inability to obtain adequate sleep; abnormal wakefulness. Insomnia is actually a symptom that may be caused by many conditions, including stress, depression, pain, or similar problems.

INST

Install

Instl

Installation

Instr

Instrument

INSTR. WD

Instruction Word

Insulin

Insulin is a hormone secreted by the pancreas that promotes glucose utilization, protein synthesis, and the formation and storage of lipids. The chemical structure of insulin is completely known and insulin obtained from various animals is used in the treatment of diabetes.

Insulin like growth factor (IGF1)

Insulin like growth factor (IGF1), also known as somatomedin, is a peptide synthesized in the liver (and probably in the kidney) that is capable of stimulating certain anabolic processes in bone and cartilage, such as the synthesis of DNA and RNA protein and the sulfation of mucopolysaccharides. Its secretion and/or biological activity is known to be dependent on growth hormone (also called somatotropin).

INTEG

Integration

Integrated Metabolic Session

To minimize the amounts of blood, urine, and saliva taken from crew members, investigators share samples (e.g. one sample is drawn, processed and distributed to multiple investigators, who then perform their own unique analysis) in Integrated Metabolic Sessions.

Integumentary

Integumentary relates to the rind, capsule or covering of any body part.

Interaural axis

The interaural axis is the imaginary line that runs between and connects the auricles (outer ears).

Intercostal

Intercostal means between the ribs.

Intercrew

Intercrew means between two or more crewmembers.

Interdisciplinary physiology

The field of interdisciplinary physiology focuses on understanding how the changes in one system of the body affects another system. In space, many processes change as a result of the nearly complete loss of gravity's downward pull. For example, microgravity causes a headward shift in fluid which changes the normal state of physiology and affects several systems of the body.

Interferometer

An interferometer is a device that is used to study a sample of protein solution by passing a laser light through the sample.

Interferon Gamma

Interferon is a substance that is produced by cells infected with a virus and has the ability to inhibit viral growth. Gamma interferon is one of the three distinct types: alpha, beta and gamma.

Interindividual

Interindividual means between two or more individuals; e.g., interindividual differences.

Interleukin

Interleukin is a family of proteins that controls aspects of the production of blood cells and platelets (hemopoiesis) and the immune response. Eight interleukins are currently characterized; interleukin 2, for instance, stimulates T-lymphocytes and is being investigated for the treatment of cancer.

International Microgravity Laboratory (IML)

The International Microgravity Laboratory (IML) missions were a series of Spacelab missions that emphasized international cooperation between the European Space Agency (ESA), The Japanese Space Agency (NASDA), the Canadian Space Agency (CSA) and NASA. These missions were dedicated to the study of both life and microgravity sciences; the life sciences experiments focused on space biology (plant, cell, and molecular and developmental biology).

International partners

International partners, space agencies and scientists from foreign countries, cooperate with the United States space agency (NASA) and U.S. scientists to conduct experiments in space. For example, the International Microgravity Laboratory-1 (IML-1) was a cooperative effort between NASA and the European Space Agency, while the Spacelab-Mir missions are a cooperative effort between the U.S. and Russia.

Interpersonal

Interpersonal means being, relating to, or involving relations between persons.

Interpersonal

Immunohistochemical is the staining of tissues using monoclonal antibodies.

Interpupillary

Interpupillary means between the pupils.

Interstitial

Interstitial means relating to spaces or interstices (small area, space or hole in the substance of an organ or tissue) in any structure.

Interval exercise

Interval exercise is exercise in which periods of high intensity alternate with periods of low intensity.

Intervertebral

Intervertebral refers to the flexible plate of fibrocartilage that connects any two adjacent vertebrae in the backbone or spine.

Intervertebral disc

An intervertebral disc is the flexible plate of fibrocartilage that connects any two adjacent vertebrae in the backbone or spine.

Intervertebral disc space

The intervertebral disc space is the space between any two vertebrae of the backbone or spine containing the intervertebral disc, a flexible plate of fibrocartilage. During exposure to microgravity this space expands, causing a height change of up to 2 inches in the astronauts while in space.

Intestinal transit time

Intestinal transit time is the time required for a particle of food to move through the small intestine, that is, from the stomach to the cecum.

Intra-acinar

Intra-acinar means inside the acinus of the lungs. The term acinus refers to that part of the airway that contains the respiratory bronchiole and all of its branches.

Intra-carotid

Intra-carotid means inside the carotid artery.

Intracellular fluid

Intracellular fluid is the fluid located within cells.

Intracellular fluid volume (ICFV)

Intracellular fluid volume (ICFV) is the fluid volume located within cells.

Intraindividual

Intraindividual means between measurements from the same individual; e.g., intraindividual differences.

Intraocular

Intraocular denotes a location inside the eyeball.

Intraocular pressure

Intraocular pressure is the pressure within the eyeball.

Intraocular tension

Intraocular tension, also called intraocular pressure, is the pressure of the fluids of the eye.

Intraoral

Intraoral means within the mouth.

Intraperitoneal

Intraperitoneal refers to location within the serous membrane of the abdominal cavity called the peritoneum.

Intrapleural

Intrapleural refers to a location within the pleura, either the covering of the lungs (visceral pleura) or of the inner surface of the chest wall (parietal pleura).

Intravascular

Intravascular refers to any location within the system of blood vessels.

Intravenous

Intravenous means into or within a vein. An intravenous injection is made into a vein.

Intravenous (IV) pump

An IV pump is a mechanical pump utilized to inject or pump fluid or solution into a vein of the human body.

Intrinsic lower back muscles

Intrinsic refers to those muscles whose origin and insertion are both in the same limb or segment of a limb. Intrinsic lower back muscles have both their origin and insertion in the lower back.

Inutest

Inutest is a substance similar to the polysaccharide inulin. It is used to test the plasma clearance, or the ability of the kidneys to clean plasma of various substances. Glomerular filtrate and plasma are very similar, except that plasma contains all the proteins which are retained in the body and not cleared in the filtrate. Glomerular filtrate and plasma contain the same concentration of inulin, therefore all glomerular filtrate is cleared of inulin. So inulin is a good measure of glomerular filtration rate and plasma clearance.

INV

Inverter

Invertebrate

An invertebrate is any animal that does not have a backbone.

IOBPS

Input-Output Box and Peripheral Simulator

IOC

Initial Operational Capability

IOC

Integrated Operations Configuration

Iodine

Iodine is an element required in small amounts for healthy growth and development. An adult body contains about 30 mg of iodine, mostly concentrated in the thyroid gland where it is needed to synthesize thyroid hormones.

Iodine 131

Iodine 131 is a radioactive tracer that binds to blood albumin. It is used to measure total circulating blood volume.

Iodine-125 (I-125)

Iodine-125 (I-125) is a radioactive isotope of iodine. It is used as an active tracer that binds to serum plasma. By measuring the amount of radioactivity emitted by I-125, plasma volume can be measured. I-125 can also be used as a tracer in thyroid studies, as therapy in hyperthyroidism and thyroid cancer, and as a label in immunoassay.

Ion

An ion is an atom or group of atoms that has acquired an electric charge through the gain or loss of an electron or electrons.

Ion-selective electrode potentiometry

Ion-selective electrode potentiometry is the measurement of electrolyte concentration (activity, to be more precise) in a solution by using an electrode with a glass membrane that is permeable to only certain ions. These ions enter the immersed electrode until their concentration inside it is the same as that in the solution outside. A reference electrode is also immersed in the solution. The electrical potential difference across the ion-selective electrode membrane is measured with a sensitive voltage meter.

Ionization

Ionization is the process of disassociating atoms or molecules into ions. An ion is an atom, group of atoms, or molecule that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.

Ionize

To ionize means to separate into ions; that is, to dissociate atoms or molecules into electrically charged atoms or radicals.

Ionized calcium

Ionized calcium is the ionic (i.e., charged) form of calcium that plays a role in muscle contractions and in regulating levels of parathyroid hormone (PTH).

Ionizing radiation

Ionizing radiation, such as that found in cosmic rays, causes atoms in the material through which it passes to lose electrons. The electrons are pulled away from the atoms by the strong attractive force between the positively charged proton (or heavy ion) and the orbital electron. Ionizing radiation can kill cells, damage their genetic material, and, in some instances, induce cancer.

IOP

Input-Output Processors

IOU

Input-Output Unit

Internet Protocols

IP & CL

Instrumentation Program and Component List

IPA

Integrated Payload Analysis

IPGOR

Integrated Payload Ground Operations Review

IPL

Integrated Payload

IPMS

Implantation Medical Telemetry System

IPOTP

Integrated Payload Operations Training Plan

IPRD

Integrated Payload Requirements Document

IPRR

Integrated Payload Requirements Review

IPS

Instrument Pointing System

Infrared

IRA

Investigation Resource Agreement

IRB

Investigation Resource Baseline

IRD

Interface Requirements Document

IRDP

Integration Readiness Data Package

IRI

Interagency Research Internet

Iridium (Ir)

Iridium is a member of the platnium group metals, also called the "noble metals," because they are among the scarcest of the metallic elements and are totally impervious to oxidation or corrosion. Iridium is a yellowish mineral with the highest corrosion resistance of any metal known. It's chemical symbol is Ir.

IRIG

Inter Range Instrumentation Group

IRN

Interface Revision Notice

Iron (Fe)

Iron is an essential element found in hemoglobin and myoglobin molecules. It is needed for hemoglobin production.

Iron economy

Iron economy refers to the measurement of red blood cell production and destruction by the process of using a radioactive isotope of iron as a type of tag. The radioactive iron is injected in harmless levels into the blood where it tags or marks the red blood cells. Afterwards, newly produced cells will be free of the isotope and destroyed, tagged cells can be counted. The balance between supply and destruction of red blood cells is termed iron economy.

Iron kinetics

Iron kinetics is the study of the rate of change of iron in the body.

IRR

Interface Requirements Review

Irritant

An irritant is something which causes inflammation, soreness, roughness, or irritability of a body part.

Interconnecting Station

ISAMS

Improved Stratospheric and Mesospheric Sounder

ISDN

Integrated Services Digital Network

ISE

Impact Statement for Experiment

ISO

International Standards Organization

Isoagglutinin

Isoagglutinin is an isoantibody that causes cells to adhere or to form clumps.

Isocapnia

Isocapnia is a state in which carbon dioxide pressure in the arteries remains constant.

Isoenzyme

An isoenzyme (or isozyme) is one of a group of enzymes that are very similar in catalytic properties, but may be differentiated by variations in physical properties, such as isoelectric point or electrophoretic mobility.

Isokinetic

Isokinetic body movements occur at the same speed regardless of the force applied.

Isokinetic dynamometer

An isokinetic dynamometer is a device that measures the strength of different muscle groups.

ISOL

Isolation

Isolation is the state of being free from external influence.

Isometric

Isometric describes the contraction of muscles when the fibers increase in tension, but do not shorten in length. Isometric exercises can be induced in muscles that are used when a limb is made to pull or push against something that does not move.

Isoproterenol

Isoproterenol is a chemical used as a drug which acts to stimulate the heart and open the air passages in asthma and other bronchial conditions.

Isotachophoresis

Isotachophoresis means "equal speed." The method consists of placing a mixture of charged particles (sample) of the same sign (co-ions) in a column or on some solid support medium containing two additional electrolytes. One electrolyte has co-ions more mobile than the sample co-ions, while the other electrolyte has co-ions less mobile than the sample co-ions. Upon application of a constant direct current, the sample co-ions initially move at different velocities until a steady state is reached. The sample ions will separate into contiguous zones with sharp interfaces in order of their mobilities. The boundaries are highly self-recuperative and will reform if stirred or disrupted by other factors, including convection.

Isothermal

Isothermal means with or at equal temperatures, or at a constant temperature.

Isotonic

Isotonic means balanced: under constant or uniform tension, or having the same concentration of osmotically active substances. An isotonic exercise is one in which a muscle contracts with a constant force, such as occurs when lifting a weight. A solution is isotonic if cells can be bathed in it without a net flow of water through the cell membrane, and two or more solutions are isotonic if they have the same concentration of osmotically active substances (salts, sugars, proteins, etc.).

Isotope

An isotope is one of two or more atoms of the same chemical element that have the same number of protons in their nucleus but different numbers of neutrons. Most elements in nature consist of a mixture of isotopes. Example: hydrogen is known to have three isotopes - hydrogen (1 proton, no neutrons), deuterium (1 proton, 1 neutron), and tritium (1 proton, 2 neutrons).

Isotopic

Isotopic refers to an isotope, the term used to describe that an element has two or more chemical properties, with the same number of protons, but different numbers of neutrons in their nucleus.

Isotypes

Isotypes refer to the classes of immunoglobulins IgG, IgA,IgM, IgD, and IgE which have similar structures but differ in molecular weight and concentration in the blood.

Isovelocity

Isovelocity is an equal or constant rate of movement, such as distance/time or work/time.

IST

Instrumentation Support Team

ISTP

International Solar Terrestrial Physics

Information Transmittal (Ames Research Center)

ITE

Intersite Transportation Equipment

ITIP

International Technical and Integration Panel

ITT

Invitation to Tender

Interface Unit

IUS

Inertial Upper Stage

IV&V

Independent Verification and Validation

IVA

Intravehicular Activity

IWFS

Integrated Waste Fluid System

IWG

Investigator Working Group

IWS

Integrated Water System

Journal Bearing

JEM

Japanese Experiment Module

JESNet

JSC Research Engineering Directorate Network

Jellyfish

JIS

Joint Integrated Simulations

Job Order

Joystick

Joystick is a term used for the handhold tool used in many computer-based video games. The joystick is designed after the steering stick of military airplanes, allowing movement in all four directions as well as rotational movement. In addition, buttons with certain functions can be located at several positions on the joystick.

JPL

Jet Propulsion Laboratory

JPOC

Johnson Space Center Payload Operations Center

JSC

Lyndon B. Johnson Space Center

JSLWG

Joint Spacelab Working Group

Junctional rhythm

Junctional rhythm is an impulse that travels anterogradely and retrogradely at the same time. Depending upon the rate of conduction in each direction, the P wave may be inscribed shortly in front of the ventricular complex, may follow the QRS, or it may be lost within it.

JURG

Joint User Requirements Group

Kilo, 1000. When Denoting Data Rates

Kilo, 210 = 1024 10. When denoting computer memory size

One Thousand (SK or KBITS)

K-Sounds

K-sounds, or Korotkoff Sounds, are heard during the measurement of systolic and diastolic blood pressures when the cuff pressure is at a certain level. The cause of the K-sounds is still debated, but they are believed to be caused by blood jetting through the partly blocked or closed artery when the cuff is inflated. They resemble tapping noises and, when heard, indicate the systolic pressure by the manometer connected to the cuff.

Karyotype

Karyotype is the chromosome characteristics of an individual or of a cell line, usually presented as a systematic array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere.

Keyboard

KBAUD

Code Elements per Second in 1,000's

KBITS

Kilobits

kbps

Kilobits per Second

Kbps/KB

Kilobits (1000s of bits) per second

KC-135

The KC-135 is a former military aircraft (a cargo version of the Boeing 707) purchased by NASA to simulate microgravity by performing parabolic flight maneuvers.

kcal

Kilocalorie

Kerley B Lines

Kerley B Lines (in radiology) are lines resembling interstitial infiltrate that appear on chest X-ray images and are associated with certain disease conditions; fine horizontal lines a few centimeters above the costophrenic angle in the chest X-ray.

Ketosteroid

A ketosteroid is a steroid-like chemical measured in the urine, which gives an indication of androgen production in the body. The major ketosteroids are androsterone, etiocholanolone and estrone.

Kilogram

Kg/hr

Kilograms per Hour

KHz

Kilohertz (Kilocycles per Second)

Konigsberg Instruments Inc. (BTS Vendor)

Kidney

The kidney is the main organ of excretion and osmoregulation in vertebrates, through which nitrogenous waste material (principally urine), water, and ions, etc. are eliminated from the body. In humans there is a pair of kidneys situated in the abdomen, below the diaphragm, on the back.

Kidney stone

A kidney stone is a hard pebble-like mass commonly composed of calcium oxalate that forms within the kidney. Some kidney stones cause pain and must be removed from the body using surgery or ultrasound techniques.

Killifish

Fundulus heteroclitus, or the killifish, is a small shallow-water minnow common along the Atlantic coast. The egg of the killifish is tough and transparent which allows easy laboratory manipulation and observation of embryo development without undue stress on the developing embryo. Killifish embryos were first flown on the Apollo Soyuz mission to study the development of the vestibular system.

Kilocalorie

A kilocalorie is the quantity of energy required to raise the temperature of one kg of water 1 degree celcius. It is 1000 times the value of a calorie.

Kilopascal (kPa)

Kilopascal (kPa) is a thousand pascals; the pascal is the international unit for pressure.

Kinematics

Kinematics is the study of motion and the forces required to produce it. This includes the different forces at work during the movement of a single part of the body, and more complex movements such as running and climbing.

Kinescope

Kinescope is a cathode-ray tube in a television receiver that translates the received signal into a picture on a luminescent screen.

Kinetic energy

Kinetic energy is energy associated with motion.

Kinetics

Kinetics is the study of acceleration, motion or rate of change.

Kjeldahl method

The Kjeldahl method is a way to chemically determine, in an organic sample, the total concentration of nitrogen that is present as ammonia or bound in organic compounds.

Klb

Kilopounds

Klebsiella pneumonia

Klebsiella pneumonia is a bacterial species found in soil and water, on grain, and in the intestinal tract of humans and other animals; it also occurs in association with several pathologic conditions, urinary tract infections, sputum, feces, and metritis in mares. Capsular types 1, 2, and 3 of this organism may be causative agents in pneumonia.

Kilometer

KMI

Kennedy Space Center Management Instruction

Knizocyte

A knizocyte is a red blood cell that has a pinched-triconcavity appearance.

Knurled

Knurled means having small ridges on the edge or surface.

Korotkoff Sounds (K-sounds)

Korotkoff Sounds or, K-sounds, occur during the measurement of systolic and diastolic blood pressures when the cuff pressure is at a certain level. The cause of the K-sounds is still debated, but they are believed to be caused by blood jetting through the partly blocked or closed artery when the cuff is inflated. They resemble tapping noises and, when heard, indicate the systolic pressure by the manometer connected to the cuff.

Kringle

Kringle is a triple-looped, disulfide-linked protein domains, found in some serine proteases and other plasma proteins, including plasminogen (5 copies), tissue plasminogen activator (2 copies), thrombin (2 copies), hepatocyte growth factor (4 copies), apolipoprotein A (38 copies).

KSC

John F. Kennedy Space Center

KUSP

Ku-Band Signal Processor

KVA

Kilo-Volt Amps

Kilowatt

kWh

Kilowatt Hours

Left Side

Length

L (IV-1)

STS Integration Level at KSC

L&L

Launch and Landing

L&L

Line-To-Line

L&PSD1

Lunar and Planetary Sciences Division

L-17.5

17.5 hours prior to launch (launch minus 17.5 hours)

Level Absolute

Lab

Laboratory

Labeled

The term "labeled" means to mark substances in a way that they can easily be identified. In life sciences, substances in the body are labeled using stable isotopes or harmless radioactive components so that they can be traced, analyzed or measured.

Labeled water (H218O)

Labeled water (H218O) is a naturally occurring form of water which contains the rare 18O isotope of oxygen (the common isotope of oxygen is 16O).

Lability

Lability means instability, or easily altered or modified, e.g. chemical instability.

Labyrinth

The labyrinth is the system of cavities and tubes that comprises the inner ear of vertebrates. It is a system of membranous structures housed within a bony cavity. The labyrinth is the portion of the inner ear that is responsible for sensing balance. Inflammation of the labyrinth (labyrinthitis) can be accompanied by vertigo and deafness.

Labyrinthine

Labyrinthine means relating to the labyrinth.

Lactic (or Lactate) Dehydrogenase (LDH)

Lactic (or Lactate) Dehydrogenase (LDH) is an enzyme found in many body tissues especially heart, liver, kidney, skeletal muscle, brain blood cells, and lungs and is involved in basic cellular metabolism. Measurement of LDH isoenzymes is helpful in differentiating the source (location) of tissue damage. LDH exists in 5 forms, called isoenzymes, which differ slightly in structure. LDH-1 is in highest concentrations in heart muscle and red blood cells. LDH-2 is highest in white blood cells. LDH-3 is highest in the lung. LDH-4 is highest in the kidney, placenta, and pancreas. LDH-5 is highest in the liver and skeletal muscle. All of these isoenzymes can be measured in the blood.

Lactulose

Lactulose is a nonabsorbable synthetic sugar used as a cathartic (laxative) in chronic constipation or in the treatment of hepatic coma. It is also used in studies of gastrointestinal transit time because it is not digested until it reaches the large intestine.

Laminar flow

Laminar flow is a nonturbulent flow in parallel layers that have different velocities.

LAMR

Large Aperture Microwave Radiometer

LAN

Local Area Network

Landing

Landing refers to the day and time when the spacecraft returns back to Earth. It is sometimes abbreviated as R+0 to indicate zero days after landing day.

LANDSAT

Land Satellite

LaRC

Langley Research Center

Large intestine

The large intestine consists of the cecum, vermiform appendix, colon, and rectum. Its primary role is the excretion of non-absorbed material passed from the small intestine, and water absorption.

LARS

Laboratory for Applications of Remote Sensing, Purdue University

Larvae

Larvae refers to the juvenile stage of most invertebrates, amphibians, and fish, which all hatch from eggs. It is unlike the adult in form and is usually incapable of sexual reproduction. It develops into the adult by undergoing metamorphosis. Examples are the tadpoles of frogs or caterpillars of butterflies.

Larynx

Larynx is the upper part of the respiratory tract between the pharynx and the trachea, having cartilaginous walls and containing the vocal cords.

LASA

Laser Atmospheric Sounder and Altimeter

Laser

A laser is a device that concentrates high energies into a narrow beam of non-spreading, monochromatic light.

Latency

Latency refers to the period between nerve stimulation and response.

Latent infection

A latent infection is an infection by a virus in which the virus lays dormant in the host cell.

Lateralis

The term lateralis indicates that a structure is located away from the mid-line of the body.

Latitude effect

Latitude effect is a variation of a quantity with latitude, especially an increase in cosmic-ray intensity with increasing magnetic latitude.

Pound

LBE

Code for Ames Research Center Life Sciences Flight Experiments Project

lbm

Pounds Mass

LBR

Low Bit Rate

LCC

Launch Control Center

LDAR

Laser Radar

LDEF

Long Duration Exposure Facility

LDL

Low Density Lipoproteins

LDR

Large Deployable Reflector

Lean body mass

Lean body mass is the weight of the body minus the fat content, or, in other words, the body mass without the fat.

LEB

Lower Electronics Box

Lectin

A lectin is a plant (usually seed) or animal protein that affects agglutination, precipitation, or other phenomena resembling the action of specific antibody, but that is not an antibody in that it was not evoked by an antigenic stimulus.

Left ventricular end-diastolic volume index (EDVI)

Left ventricular end-diastolic volume index (EDVI) is the volume measured in the left ventricle at the end of diastole (period of the heart's relaxation), with body size taken into account.

Left ventricular end-systolic volume index (ESVI)

Left ventricular end-systolic volume index (ESVI) is the volume measured in the left ventricle at the end of systole (period of the heart's contraction), with body size taken into account.

Left ventricular stroke volume

Left ventricular stroke volume, also called stroke volume, is the volume of blood (normally about 70 milliliters) ejected into the aorta during the contraction of the heart's ventricles.

Leg volume

Leg volume refers to the actual volume of the leg, a measurement taken to indicate changes in muscle size, either associated with changes in muscle size, or in the amount of fluid located in the tissues of the leg. Often taken during space flight or bed rest studies that are investigating changes in fluid volume or muscle size.

Lentil

A lentil is the round, flattened, edible seed of a pea-like Old World plant also called a lentil. It is a member of the leguminosae group - plants with the ability to use nitrogen in the air for nutrition.

LEO

Low Earth Orbit

Leptocyte

A leptocyte is a red blood cell characterized as being thin and flat in appearance.

Leq

Level Equivalent

LeRC

Lewis Research Center

Lesion

A lesion is a scar, or tissue that is damaged.

LET

Light Energy Transfer

Leukemia

Leukemia is any group of malignant diseases in which the bone marrow and other blood forming organs produce increased numbers of leukocytes (white blood cells).

Leukocyte

A leukocyte is a white blood cell, specifically a colorless cell with a nucleus, found in blood and lymph. Leukocytes are capable of amoeboid movement. They can produce antibodies and move through the walls of vessels to migrate to sites of injury, where they isolate and destroy dead tissue, foreign protein and bacteria.

Leukocytosis

Leukocytosis is an abnormal increase in the number of circulating white blood cells, which usually accompanies bacterial, but not viral, infections. Types of leukocytosis are basophilia, eosinophilia, and neutrophilia.

Leukopenia

Leukopenia is a reduction in the number of white blood cells (leukocytes) in the blood.

Leukotriene

One of a group of hormones that cause the symptoms of hayfever and asthma. Derived from arachidonic acid, the leukotrienes act by mediating immediate hypersensitivity.

Lexan

Lexan is a trademark name for polycarbonate, which is any of a family of thermoplastics characterized by high-impact strength, flexibility, and light weight; it is used as a shatter-resistant substitute for glass.

Load Factor

LFMR

Low Frequency Microwave Radiometer

Left Hand

LH2

Liquid Hydrogen

LHCP

Left Hand Circularly Polarized

Libration

Libration is an oscillation in the apparent aspect of a secondary body (such as a planet or satellite) as seen from the primary object around which it revolves.

Libration clouds

Libration clouds are small celestial particles trapped in regions of the Earth-Moon system where gravitational and centrifugal forces acting on them cancel each other.

LIF

Life Sciences

Life support systems

Life support systems are the hardware and resources that provide the necessities vital for life, namely, oxygen, water and food for space travelers. Temperature regulation, carbon dioxide removal and waste management systems are considered subsystems of life support systems.

Ligament

Ligaments are resilient but flexible tissues which hold two or more bones together at a movable joint. Ligaments restrain the movement of bones at a joint and are therefore important in preventing dislocation. They consist primarily of collagen.

Light Emitting Diode (LED)

A Light Emitting Diode (LED) is a very small light often used in electronic instrumentation.

Light flash phenomenon

Light flash phenomenon is a visual phenomenon or event that is experienced when a person is exposed to cosmic ionic particles, similar to, but brighter than, a shooting star in the night sky. Although the exact cause of this phenomenon is unknown, it is believed that visual flashes result from direct ionizing energy loss as the particle traverses the cells of the eye.

Light microscopy

Light microscopy is the inspection of a substance or object with the use of a light microscope. A light microscope uses visible light to help provide an enlarged image of an object or substance that is very small or not visible to the naked eye.

Light scatter

Light scatter is the deflection of a light beam by obstacles, such as dust particles, in a medium such as air.

Light unit

The light unit of the Svet greenhouse is inserted into the top of the growth chamber and can be set at three different positions, at distances of 20, 30 and 40 centimeters from the root module surface, to allow for maximum illumination during plant growth. It contains six units that each contain fluorescent bulbs.

Lignin

Lignin is a substance related to cellulose that provides rigidity and together with cellulose forms the woody cell walls of plants and the cementing material between them.

Linear acceleration

Linear acceleration is the rate of change of velocity in a linear direction (along a straight line) with respect to time.

LiOH

Lithium Hydroxide

Lipase

Lipase is an enzyme, secreted by the pancreas and the glands of the small intestine, that breaks down fats into glycerol and fatty acids during digestion.

Lipid

A lipid is one of a group of naturally occurring compounds, also known as fats, that are soluble in organic solvents such as chloroform or alcohol, but insoluble in water. Lipids are important dietary constituents, not only because of their high energy value, but also because certain vitamins and essential fatty acids are associated with them.

Liquid scintillation counter

Scintillation counting is a technique for measuring the quantity of a radioactive isotope present in a sample. In biology, liquid scintillation counting is mainly used for isotopes such as carbon 14, sulfur 35 and phosphorous 32 and particularly for the low energy emission of hydrogen 3. Gamma emissions are often measured by counting the scintillations that they cause in a crystal. Autoradiographic images can be enhanced by using a screen of scintillant behind the film.

Liquid-liquid diffusion crystallization

Liquid-liquid diffusion crystallization is a technique used for growing protein crystals. It consists of a protein solution and precipitating solution separated by an liquid interface. Diffusion across the interface saturates the protein solution causing the proteins to crystallize.

Lithium chloride (LiCl2)

Lithium chloride is a substance used as an inert tracer in the determination of fluid volume by the lithium dilution technique.

Liver

The liver is the largest gland of the body, weighing between 1200-1600 grams, and is situated in the top right portion of the abdominal cavity. The liver is divided by fissures into four lobes. The liver plays an essential role in many metabolic processes by regulating the composition and concentration of nutrients and toxic materials in the blood. Its functions include synthesizing bile and blood coagulating factors, acting as the site of metabolism of carbohydrates, proteins and fats, regulating the amount of blood sugar, converting excess glucose to glycogen, removing excess amino acids, storing and metabolizing fats, and detoxifying poisonous substances, worn out red blood cells and other unwanted material.

LIVIR

Level IV Integration Requirements

LIVR

Level IV Readiness

LL-TV

Low Light Level Television

LLPRD

Launch and Landing Program Requirements Document

Long Module

LMMI

Large Mass Measurement Instrument

LMSC

Lockheed Missiles & Space Company

LN2

Liquid Nitrogen

LNH

Launch

LNK

Link

Load

A load is the overall force to which a structure is subjected in supporting a weight or mass or in resisting externally applied forces.

The term loading refers to gravitational loading, or the application of force to a bone or part of the body. Under normal circumstances on Earth, gravity "loads" the bones and muscles with the force required to support the body.

Local

Local means having reference or confined to a limited area, not general or systemic.

Locomotion

Locomotion is the act of moving, or the ability to move, from place to place.

Locomotor

Locomotor refers to locomotion, the ability of an organism to move in a particular direction in its environment. In animals, the force required to initiate locomotion is generated by voluntary muscle contractions.

Locus ceruleus

The locus ceruleus is a small pigmented region in the floor of the fourth ventricle of the brain; the region is made up of about 20,000 melanin-pigmented neuronal cell bodies whose norepinephrine-containing axons have a remarkably wide distribution in the cerebellum as well as in the hypothalamus and cerebral cortex of the brain.

LOE

Level of Effort

Log

A log is a detailed record of a voyage, flight, or experiment. It may be specific to food, exercise, medications, etc.

Lomotil

Lomotil is the trademark for an antidiarrheal fixed-combination drug containing an antiperistaltic and an anticholinergic.

Longissimus

The longissimus is the intermediate division of the erector spinae muscle having three subdivisions: musculus longissmus capitus (keeps the head erect), m. l. cervicus (extends cervical vertebrae) and m. l. thoracis (extends the vertebral column).

Lordosis

Lordosis is the normal curvature of the lumbar and cervical spine, seen as an anterior concavity if the person is observed from the side.

LOS

Loss of Signal (Telemetry)

LOS

Loss of Sight

Lower Body Negative Pressure (LBNP)

Lower body negative pressure (LBNP) is applied by placing the lower body (legs and hips) in a sealed chamber. Suction applied to the chamber causes body fluid to move from the chest and upper body to the lower body. This shift of fluid is very similar to the shift of fluid that occurs when people stand upright.

LOX

Liquid Oxygen

Line Printer

LPF

Large Primate Facility

LPS

Launch Processing System

LQP

Letter Quality Printer

LRSI

Low Temperature Reusable Surface Insulation

LRU

Line Replaceable Unit

LRV

Launch Readiness Verification

Life Sciences

LS-1

Life Sciences 1 (Mission)

LSA

Large Space Antenna

LSB

Least Significant Bit

LSDA

Life Sciences Data Archive

LSDF

Life Sciences Data Facility

LSE

Life Sciences Experiments

LSFEP

Life Sciences Flight Experiments Program

LSFP

Life Sciences Flight Projects

LSGSSS

Life Science Guide to the Space Shuttle and Spacelab

LSI

Launch Site Integration

LSI

Large Scale Integrated

LSIS

Life Sciences Information System

LSL

Life Sciences Laboratory

LSLE

Life Sciences Laboratory Equipment

LSPD

Life Science Project Division

LSPDPM

Life Science Payload Development Program Management Plan

LSPE

Launch Site Payloads Engineer

LSPIWG

Life Science Payload Inter-Center Working Group

LSPO

Life Sciences Projects Office

LSPS

Life Support and Protective Systems

LSRF

Life Sciences Research Facility

LSSC

Life Sciences Steering Committee

LSSF

Life Sciences Support Facility

LSSM

Launch Site Support Manager

LSSP

Launch Site Support Plan

LSSSPO

Life Sciences Space Station Projects Office

LSST

Launch Site Support Team

Lumbar

Lumbar means relating to the loins, or the part of the back and sides between the ribs and the pelvis.

Lumbar 3

The lumbar 3 is the third vertebrae (counted from the head) of the lumbar spine.

Lumbar spine

The lumbar spine, or lumbar vertebrae, are the five bones of the backbone that are situated between the thoracic vertebrae and the sacrum in the lower part of the back. They are the largest of the unfused vertebrae and have stout processes for attachment of the strong muscles of the lower back.

Lumbar vertebrae

The lumbar vertebrae are the five bones of the backbone that are situated between the thoracic vertebrae and the sacrum in the lower part of the back. They are the largest of the unfused vertebrae and have stout processes for attachment of the strong muscles of the lower back.

Lumbosacral

Lumbosacral refers to the group of motor neurons which connect the lower spinal cord to muscles of the lower back, gluteal region, and various other parts of the body.

Luminous

Luminous means emitting light.

Lung water

Lung water is the fluid in the pulmonary extravascular space. Excessive water accumulates in the lung during disease or when edemas are present. The lung water causes impaired perfusion and breathing, depriving the body of oxygen.

Local Vertical

LVL

Level

LVLH

Local Vertical Local Horizontal

Lymph nodes

Lymph nodes are one of a number of small swellings found at intervals along the lymphatic system. Groups of nodes are found in many parts of the body; for example, in the groin and armpit and behind the ear. They are composed of lymphoid tissue and act as filters for the lymph, preventing foreign particles from entering the bloodstream; they also produce lymphocytes.

Lymphocyte

A lymphocyte is a type of white blood cell present in blood, lymph nodes, spleen, thymus gland, gut wall and bone marrow. Important to the immune system, they produce circulating antibodies and T-lymphocytes, which are primarily responsible for cell-mediated immunity and can differentiate into helper, killer or suppressor cells.

Lymphocyte proliferation

Lymphocyte proliferation means that after lymphocytes encounter an antigen or foreign protein, they begin a process by which they rapidly reproduce themselves, so that there are many lymphocytes available which can recognize and fight the invading antigens.

Lymphokine

A lymphokine is a soluble substance released by sensitized lymphocytes on contact with specific antigen, which help effect cellular immunity by stimulating activity of monocytes and macrophages. These include chemotactic, mitogenic, migration-inhibitory, transfer factors, lymphotoxin and immune (antigen) interferon.

Lymphoma

A lymphoma is any malignant tumor of the lymph nodes, including Hodgkin's disease.

Lymphopenia

Lymphopenia is a decrease in the number of lymphocytes (a variety of white blood cells) in the circulating blood, which may occur in a wide variety of diseases.

Lyophilyzed

Lyophilized or lyophilization is the process of freeze-drying, which is the removal of liquid from heat-sensitive materials. The material is frozen, placed under a high vacuum, and maintained at a low temperature. The pressure generated by the vacuum causes the ice to turn from a solid to a gaseous form without passing through a liquid state.

Lysis

Lysis is a rupture of cell membranes and loss of cytoplasm.

Lysozyme

Lysozyme is an enzyme that hydrolyzes the 1,4-beta links between N-acetylmuramic acid and N-acetylglucosamine, and thus destructive to cell walls of certain bacteria. It is present in tears and other body fluids, in egg whites and in some plant tissues.

Meter, Milli

Million

Mega = 106 when denoting data rates

M&P

Materials and Processes

M-S

Mission Station

m/s2

Meters per Second Squared

Mega 2 = 1,048,576 When Denoting Computer Memory Size

Meters Squared

Mission Management

Cubic Meters

Macromolecular

Macromolecular describes a molecule of colloidal size such as proteins, nucleic acids, and polysaccharides.

Macromolecule

A macromolecule is a polymer, especially one composed of more than 100 repeated monomers (which are single chemical units). A biological macromolecule is one which is involved in the processes of life and living organisms, such as proteins (haemoglobuliu) and deoxyribonucleic acid or DNA.

Macrophage

A macrophage is a large scavenger cell present in connective tissue and many major organs and tissues including the bone marrow, spleen, lymph nodes, liver and the central nervous system. Macrophages ingest bacteria and cell debris and are responsible for the breakdown of worn-out red blood cells.

Macula

The macula is a small anatomical area in the inner ear and the eye; it contains an increased number of nerve cells. In the inner ear, it is the patch of sensory hair that provides information about the position of the body in relation to gravity, also known as the otolith organ of the ear. In the eye, the macula is a shallow depression in the retina of the eye, opposite the lens. It contains a large concentration of cones and is specialized for the perception of color and sharp intense images.

Magnesium (Mg)

Magnesium is a silvery metallic element essential to life. It is necessary for the proper functioning of muscle and nervous tissue and is involved in the transmission of nerve impulses.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) is a noninvasive, nondestructive method of creating three-dimensional, internal images of the soft tissues of the body, including the brain, spinal cord and muscle by applying a magnetic field to the body in a constant radio frequency field. MRI is an application of nuclear magnetic resonance, and depends on measurement of the magnetic moment of hydrogen atoms in the body to determine structure.

Magnitude

Magnitude is a property that can be quantitatively described, such as the volume of a sphere or the length of a vector.

Malaise

Malaise is an indefinite feeling of weakness or lack of health which is often indicative of or accompanying the onset of an illness.

Mammalian

Mammalian means referring to mammals, a class of vertebrates containing some 4250 species. Mammals are warm-blooded animals, typically having sweat glands whose secretion cools the skin and an insulating body covering of hair. All mammals have mammary glands, which secrete milk to nourish the young.

Mandible

The mandible is the lower jawbone of vertebrates; either of the two parts of a bird's beak; and a pair of horny mouth parts in insects, crustaceans, centipedes, and millipede, assisting in biting and crushing the food.

Manometer

A manometer is an instrument used to measure the pressure of any fluid or the difference in pressure between two fluids, whether gas or liquid.

Marangoni convection

Marangoni convection is the primary surface tension-driven force in a float zone. Thermal gradients along the free surface of the float zone drive the convection.

MAS

Macro Assembler

Mass

Mass is the characteristic of a body that is considered a measure of the amount of material it contains and causes it to have weight in a gravitational field. The mass of a body always has the same value; weight changes with change in the acceleration of gravity.

Mass spectrometer

A mass spectrometer is an instrument used for measuring the intensity and wavelengths of visible or invisible electromagnetic radiation.

Mass spectrometry

Mass spectrometry is a procedure used to identify chemicals by ionizing them and sorting the ions by mass and electrical charge.

Mastoid process

The mastoid process is the nipple-like projection of the petrous part of the temporal bone.

MAWP

Maximum Allowable Working Pressure

max

Maximum

Maxilla

For vertebrates, the maxilla is the upper jaw, which bears the upper teeth (except the incisors). For insects, crustaceans, centipedes, and millipedes, it is a mouth part assisting in feeding.

Maxillary sinusitis

Maxillary sinusitis is an inflammation of the one or more paranasal sinuses. It may be a complication of an upper respiratory infection, dental infection, allergy, a change in atmosphere, or a structural defect of the nose.

Maximal aerobic work capacity

Maximal aerobic work capacity (also called maximal exercise capacity) is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.

Maximal exercise capacity

Maximal exercise capacity (also called maximal aerobic work capacity) is the maximum ability of the body to take up and use oxygen to do work. This is often reported as the maximum number of liters of oxygen that the body can use in a minute.

Maximal Expiratory Flow Volume (MEFV)

The Maximal Expiratory Flow Volume (MEFV) occurs when a person expires with great force, and the expiratory air flow reaches a maximum flow beyond which the flow cannot be increased even with greatly increased additional force.

Maximal heart rate

Maximal heart rate is two-hundred twenty (220) minus the subject's age in years.

Maximal oxygen consumption (max VO₂)

Maximal oxygen consumption is the point at which the oxygen consumption plateaus and shows no further increase (or increases only slightly) with an additional workload. Also called maximal oxygen uptake, maximal aerobic power, or max VO_2.

Maximum voluntary contraction (MVC)

A maximum voluntary contraction (MVC) is the largest force that can be voluntarily exerted by a muscle.

Megabyte

MBD

Company, Graphics System Vendor

MBE

Molecular Beam Epitaxial

MBIS

Mobile Biological Isolation Station

MBITS

Megabits

mbps

Megabits per Second

Mbyps

Megabytes per Second

MCC

Mission Control Center

MCDS

Multifunction CRT Display System

MCS

Material Control System

MCS

Material Control Station

Man Day

Mission Day

MDAC

McDonnell Douglas Astronautics Company

MDE

Mission Dependent Equipment