| 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) |
| acidophil granule | A granule that stains with an acid dye such as eosin. Synonym: oxyphil granule. (05 Mar 2000) |
| acrosomal granule | The single glycoprotein rich granule within an acrosomal vesicle, which results from the coalescence of proacrosomal granule's. (05 Mar 2000) |
| alpha granule | A granule of an alpha cell that was named as the first of several kinds or because it was acidophilic. (05 Mar 2000) |
| Altmann's granule | A granule that has an affinity for fuchsin. Synonym: Altmann's granule. (05 Mar 2000) |
| amphophil granule | A granule that stains with both acid and basic dyes. (05 Mar 2000) |
| atrial granule serine proteinase | <enzyme> Converts pro-atrial natriuretic factor to anf by cleaving the arg98-ser99 bond; n-terminal 26-residue amino acid sequence given in first source Registry number: EC 3.4.21.- (26 Jun 1999) |
| azurophil granule | <cell biology> Primary lysosomal granules found in neutrophil granulocytes, contain a wide range of hydrolytic enzymes. Sometimes referred to as primary granules to distinguish them from the specific or secondary granules. (02 Jan 1998) |