| absolute refractory period | The period following excitation when no response is possible regardless of the intensity of the stimulus. (05 Mar 2000) |
|---|---|
| absolute risk | <statistics> The excess risk due to exposure to a specific hazard (disease, injury, etc.) (15 Jan 1998) |
| absolute scale | An obsolete term for Kelvin scale. (05 Mar 2000) |
| absolute scotoma | A scotoma in which there is no perception of light. (05 Mar 2000) |
| absolute system of units | A system based on absolute units accepted as being fundamental (length, mass, time) and from which other units (force, energy or work, power) are derived; such system's in common use are the foot-pound-second, centimeter-gram-second, and meter-kilogram-second system's. (05 Mar 2000) |
| absolute temperature | Temperature reckoned in Kelvins from absolute zero. (05 Mar 2000) |
| absolute terminal innervation ratio | The number of motor endplates divided by the number of terminal axons related to them. (05 Mar 2000) |
| absolute unit | A unit whose value is constant regardless of place or time and not derived from dependent on gravitation. (05 Mar 2000) |
| absolute viscosity | Force per unit area applied tangentially to a fluid, causing unit rate of displacement of parallel planes separated by a unit distance; units in CGS system: poise. (05 Mar 2000) |
| absolute zero | <chemistry, physics> This is the lowest possible temperature (0 Kelvin, -273.15 degrees Celsius, -459.67 degrees Fahrenheit). at this temperature, all molecular motion stops. (15 Jan 1998) |
| atmosphere absolute | <physics> A unit of absolute pressure (also known as barometric pressure) expressed in atm. (05 Mar 2000) |
| CD4 count, absolute | The number of helper T-lymphocytes in a cubic millimeter of blood. With HIV, the absolute CD4 count declines as the infection progresses. The absolute CD4 count is frequently used to monitor the extent of immune suppression in persons with HIV. Also called a T4 count. (12 Dec 1998) |
| achromatic threshold | Threshold of visual sensation, the minimal light intensity evoking a visual sensation. Synonym: achromatic threshold, minimum light threshold. (05 Mar 2000) |
| anaerobic threshold | The oxygen consumption level above which aerobic energy production is supplemented by anaerobic mechanisms during exercise, resulting in a sustained increase in lactate concentration and metabolic acidosis. The anaerobic threshold is affected by factors that modify oxygen delivery to the tissues; it is low in patients with heart disease. Methods of measurement include direct measure of lactate concentration, direct measurement of bicarbonate concentration, and gas exchange measurements. (12 Dec 1998) |
| auditory threshold | The audibility limit of discriminating sound intensity and pitch. (12 Dec 1998) |