| polar presentation | The presentation of either pole of the foetal oval; may be either a cephalic or breech presentation, or a longitudinal lie. (05 Mar 2000) |
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| polar ring | A thickened, electron-dense ring at the anterior end of certain stages of the Apicomplexa; part of the apical complex characteristic of these sporozoans. (05 Mar 2000) |
| polar solvents | Solvent's that exhibit polar forces on solutes, due to high dipole moment, wide separation of charges, or tight association; e.g., water, alcohols, acids. (05 Mar 2000) |
| polar star | One of the figures forming the diaster. Synonym: polar star. (05 Mar 2000) |
| polar zone | The region in the vicinity of an electrode applied to the body. See: electrotonus. (05 Mar 2000) |
| electro-polar | <physics> Possessing electrical polarity; positively electrified at one end, or on one surface, and negatively at the other; said of a conductor. Source: Websters Dictionary (01 Mar 1998) |
| zinco-polar | <physics> Electrically polarized like the surface of the zinc presented to the acid in a battery, which has zincous affinity. Source: Websters Dictionary (01 Mar 1998) |
| law of polar excitation | A given segment of a nerve is irritated by the development of catelectrotonus and the disappearance of anelectrotonus, but the reverse does not hold; i.e., excitation occurs at the cathode when the circuit is closed and at the anode when it is opened. Synonym: Pfluger's law. (05 Mar 2000) |
| achlorhydric anaemia | A form of chronic hypochromic microcytic anaemia associated with achlorhydria or achylia gastrica; observed most frequently in women in the third to fifth decades. Synonym: Faber's anaemia, Faber's syndrome. (05 Mar 2000) |
| achrestic anaemia | A form of chronic progressive macrocytic anaemia that can be fatal in which the changes in bone marrow and circulating blood closely resemble those of pernicious anaemia, but in which there is only transient or no response to therapy with vitamin B12; glossitis, gastrointestinal disturbances, central nervous system disease, and pyrexia are not observed, and there is only little bleeding or haemolysis. Origin: G. A-priv. + chresis, a using (05 Mar 2000) |
| acquired haemolytic anaemia | Nonhereditary acute or chronic anaemia associated with or caused by extracorpuscular factors, e.g., certain infectious agents, chemicals (including autoantibodies or therapeutic agents), burns, toxic materials from higher plant and animal forms (including snake venoms). (05 Mar 2000) |
| addisonian anaemia | <haematology> A form of anaemia (low red blood cell counts) that results when the bone marrow fails to produce adequate numbers of red blood cells due to a deficiency in vitamin B12. Intrinsic factor, necessary for normal B12 absorption, may be the underlying cause for B12 deficiency if is not produced in the gastric glands (in the stomach). Origin: Gr. Haima = blood (27 Sep 1997) |
| Addison's anaemia | <haematology> A form of anaemia (low red blood cell counts) that results when the bone marrow fails to produce adequate numbers of red blood cells due to a deficiency in vitamin B12. Intrinsic factor, necessary for normal B12 absorption, may be the underlying cause for B12 deficiency if is not produced in the gastric glands (in the stomach). Origin: Gr. Haima = blood (27 Sep 1997) |
| anaemia | <haematology> Too few red blood cells in the bloodstream, resulting in insufficient oxygen to tissues and organs. Origin: Gr. Haima = blood (16 Dec 1997) |
| anaemia, aplastic | A form of anaemia in which the bone marrow fails to produce adequate numbers of peripheral blood elements. (12 Dec 1998) |