| extraction | The process or act of pulling or drawing out. Origin: L. Trahere = to draw (18 Nov 1997) |
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| extraction and processing industry | The industry concerned with the removal of raw materials from the earth's crust and with their conversion into refined products. (12 Dec 1998) |
| extraction coefficient | The percentage of a substance removed from the blood or plasma in a single passage through a tissue; e.g., the extraction coefficient for p-aminohippuric acid (PAH) in the kidney is the difference between arterial and renal venous plasma PAH concentrations, divided by the arterial plasma PAH concentration. (05 Mar 2000) |
| extraction, obstetrical | Extraction of the foetus by means of obstetrical instruments. (12 Dec 1998) |
| extraction ratio | The fraction of a substance removed from the blood flowing through the kidney; it is calculated from the formula (A -V)/A, where A and V, respectively, are the concentrations of the substance in arterial and renal venous plasma. (05 Mar 2000) |
| sperm | A reproductive cell produced by the male of an animal species which, when united with an egg (of the same species), results in conception and the development of an embryo. (09 Oct 1997) |
| sperm agglutination | Agglutination of spermatozoa. (05 Mar 2000) Previous: Spens, Thomas, spent, speract, sperling, sperm, spermaceti, spermacytic seminomaNext: sperm agglutination, spermalist, spermaphore, spermary, sperm-astersperm agglutination Agglutination of spermatozoa by antibodies or autoantibodies. (12 Dec 1998) |
| sperm-aster | Cytocentrum with astral rays in the cytoplasm of an inseminated ovum; it is brought in by the penetrating spermatozoon and evolves into the mitotic spindle of the first cleavage division. Origin: sperm + G. Aster, a star (aster) (05 Mar 2000) |
| sperm bank | A facility where sperm are kept frozen in liquid nitrogen for later use in artificial insemination. (09 Oct 1997) |
| sperm banking | <procedure> The freezing of sperm for future use. This procedure can allow men to father children after loss of fertility, as in the case following chemotherapy for cancer. (12 May 1997) |
| sperm banks | Centres for acquiring and storing semen. (12 Dec 1998) |
| sperm capacitation | The process by which a spermatozoon becomes capable of fertilizing an ovum after it reaches the ampullary portion of the uterine tube. (12 Dec 1998) |
| sperm cell | Mature sperm cell (male gamete). (18 Nov 1997) |
| sperm count | The number of sperm in the ejaculate (when given as the number of sperm per millileter it is more accurately known as the sperm concentration or sperm density). (09 Oct 1997) |
| sperm crystal | A crystal of spermin phosphate found in the semen; possibly identical to Bottcher's crystal's. (05 Mar 2000) |