| MEC | median effective concentration; middle ear canal; middle ear cell; minimum effective concentration |
|---|---|
| MEP | maximum expiratory pressure; mean effective pressure; mepiridine; mitochondrial encephalopathy; moto... |
| MAP | malignant atrophic papulosis; mandibular angle plane; maturation-activated protein; maximal aerobic ... |
| PP | diphosphate group; emphysema [pink puffers]; near point of accommodation [Lat. punctum proximum]; pa... |
| EEP | end-expiratory pressure; equivalent effective photon |
| effective collision radius | <radiobiology> Effective size of a particle equal to the square root of (cross-section/pi). Determines the effective range of interaction of the particle. (09 Oct 1997) |
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| effective conjugate | The internal conjugate measured from the nearest lumbar vertebra to the symphysis, in spondylolisthesis. Synonym: false conjugate. (05 Mar 2000) |
| effective dose | The dose that produces the desired effect; when followed by a subscript (generally "ED50"), it denotes the dose having such an effect on a certain percentage (e.g., 50%) of the test animals; ED50 is the median effective dose, in radiation protection, the sum of the equivalent doses in all tissues and organs of the body weighted for tissue effects of radiation. The unit of effective dose is the sievert (Sv), epilation dose, the minimum amount of radiation sufficient to produce hair loss, usually in 10 to 14 days. (05 Mar 2000) |
| effective half-life | <radiobiology> Time required for a radioactive substance contained in a biological system (such as a person or an animal) to reduce its radioactivity by half, as a combination result of radioactive decay and biological elimination from the system. (09 Oct 1997) |
| effective refractory period | The period during which impulses may appear but are too weak to be conducted; the longest interval between adequate stimuli, falling just short of the time necessary to allow a propagated response to be evoked in a tissue by the second stimulus; it differs from the functional refractory period in that it is a measure of stimulus interval rather than response interval of time. (05 Mar 2000) |
| effective renal blood flow | The amount of blood flowing to the parts of the kidney that are involved with production of constituents of urine. (05 Mar 2000) |
| effective renal plasma flow | <physiology> The amount of plasma flowing to the parts of the kidney that have a function in the production of constituents of urine; the clearance of substances such as iodopyracet and p-aminohippuric acid, assuming that the extraction ratio in the peritubular capillaries is 100%. It is the amount of plasma perfusing the kidney tubules per unit time, generally measured by p-aminohippurate clearance. It should be differentiated from renal plasma flow which is approximately 10% greater than the effective renal plasma flow. (07 Mar 2000) |
| effective temperature | A comfort index or scale which takes into account the temperature of air, its moisture content, and movement. (05 Mar 2000) |
| effective temperature index | A composite index of environmental comfort which is compared after exposure to different combinations of air temperature, humidity, and movement. (05 Mar 2000) |
| abdominal pressure | Pressure surrounding the bladder; estimated from rectal, gastric, or intraperitoneal pressure. (05 Mar 2000) |
| absolute pressure | Pressure measured with respect to zero pressure. Compare: gauge pressure. (05 Mar 2000) |
| acoustic pressure | In ultrasound, the instantaneous value of the total pressure minus the ambient pressure; unit is pascal (Pa). (05 Mar 2000) |
| air pressure | The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment. (12 Dec 1998) |
| atmospheric pressure | The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned. (12 Dec 1998) |
| back pressure | Pressure exerted upstream in the circulation as a result of obstruction to forward flow, as when congestion in the pulmonary circulation results from stenosis of the mitral valve or failure of the left ventricle. (05 Mar 2000) |