F
1-10 A B C D E F G H I J K L M N O P Q R S T U V W XYZFAS
- FAS is a molecule found on cell surfaces. Immunologist have designated it CD95. When engaged by it's ligand, it induces cellular apoptosis (See apoptosis).
-
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 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. These fibers use no oxygen for energy, thus are called anaerobic.
-
Fatigability is a measure of the rate at which fatigue is induced.
-
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.
-
A fatigue test is a test which determines how much work/activity can be accomplished by different muscles before their efficiency is reduced.
-
The femur, also called the thigh bone, is the long bone between the hip and the knee.
-
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 is iron with a valence of three.
-
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 is iron with a valence of two.
-
Fibrinogen is a substance present in blood plasma that causes blood coagulation.
-
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 means regarded or employed as a standard of reference
-
Filamentous means composed of filaments or threadlike structures. 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.
-
A finger cot is a latex sheath for the finger.
-
Finger pulse volume is a physiological parameter which is a measure of variations in the size of the finger resulting from changes in the amount of blood present.
-
Firing frequency is the rate (or frequency) of the excitation of nerve or muscle fibers (called firing).
-
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.
-
The term "fixed" refers to a chemical treatment of tissue or cells that results in preservation.
-
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.
-
Flash frozen means the process of freezing multiple solutions with liquid nitrogen to prevent diffusion between them until they are allowed to thaw.
-
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.
-
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 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 is the first stage of flower production.
-
Flow cytometry is an analytic tool that allows for the quantitation of different kinds of molecules expressed on cells in suspension. This technique primarily uses fluorescent properties of probes such as antibodies to detect molecule expression, however, analyses based on cell size and granularity are also possible.
-
Fluence refers to the ease with which particles flow.
-
Fluid balance is the relationship between fluid intake and fluid output. A negative fluid balance means that more fluid was put out than taken in during a given time period; a positive fluid balance is the opposite.
-
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 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 is the use of a light microscope that uses fluorescent light to analyze specimens.
-
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.
-
A fluorometer is an instrument used to measure the intensity of radiation.
-
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.
-
Fomite is a non-living material, such as bed linen, which may convey pathogenic organisms.
-
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.
-
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.
-
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) 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.
-
Formaldehyde is a pungent gas; in liquid form, it is used as an antiseptic, disinfectant and fixative for tissues.
-
Formalin is a 37% aqueous solution of formaldehyde, used as a histologic fixative.
-
Fractionation means to separate components of a mixture.
-
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.
-
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.
-
The functional residual capacity is the amount of air remaining in the lungs at the end of normal expiration (about 2300 ml).
-
Fungi are any of a large group of plants which do not contain chlorophyll, including the yeasts, molds, and mushrooms.
-
Furunculosis is a condition marked by the presence of localized pyogenic infection originating in the hair follicle.
-
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.