| incomplete foot presentation | See: breech presentation. (05 Mar 2000) |
|---|---|
| transverse presentation | An abnormal presentation, neither head nor breech, in which the foetus lies transversely in the uterus across the axis of the parturient canal. (05 Mar 2000) |
| labour presentation | The part of the foetal body that is in advance in the birth canal. (12 Dec 1998) |
| footling presentation | <obstetrics> There are single-footling or double-footling presentations depending upon whether the presenting part of the baby at delivery is just one foot or both feet. (12 Dec 1998) |
| full breech presentation | The thighs may be flexed on the abdomen and the legs upon the thighs, in footling presentation foot presentation the feet may be the lowest part; in incomplete foot presentation, incomplete knee presentation, one leg may retain the position which is typical of one of the above-mentioned presentations, while the other foot or knee may present. Synonym: pelvic presentation. (05 Mar 2000) |
| polar | Describes a feature or phenomenon occuring at the end (pole) of an object (such as a planet) or organism (such as an amoeba). <chemistry> Describes a molecular that has a permanent electric dipole. See: polar group. Compare: nonpolar, nonpolar groups. (12 Mar 1998) |
| polar amino acid | An alpha-amino acid in which the functional group attached to the alpha-carbon (i.e., R in RCH(NH2)COOH) has hydrophilic properties; e.g., serine, cysteine, homocysteine. (05 Mar 2000) |
| polar anaemia | A form of anaemia sometimes observed in natives of temperate climates when they migrate to the Arctic or Antarctic regions. (05 Mar 2000) |
| polar body | <cell biology> In animals each meiotic division of the oocyte leads to the formation of one large cell (the egg) and a small polar body as the other cell. Polar body formation is a consequence of the very eccentric position of the nucleus and the spindle. (18 Nov 1997) |
| polar cataract | A capsular cataract limited to an area of the anterior or posterior pole of the lens. (05 Mar 2000) |
| polar cell | <cell biology> In animals each meiotic division of the oocyte leads to the formation of one large cell (the egg) and a small polar body as the other cell. Polar body formation is a consequence of the very eccentric position of the nucleus and the spindle. (18 Nov 1997) |
| polar compound | A compound in which the electric charge is not symmetrically distributed, so that there is a separation of charge or partial charge and formation of definite positive and negative poles; e.g., H2O. See also inorganic compound. (05 Mar 2000) |
| polar fibres | Those fibres of the mitotic spindle extending from the two poles of the spindle toward the equator. Compare: astral fibres, kinetochore fibres. (05 Mar 2000) |
| polar flagellation | <cell biology> Condition of having flagella attached at one end or both ends of the cell. (09 Oct 1997) |
| polar globule | <cell biology> In animals each meiotic division of the oocyte leads to the formation of one large cell (the egg) and a small polar body as the other cell. Polar body formation is a consequence of the very eccentric position of the nucleus and the spindle. (18 Nov 1997) |