| polar plates | Condensed platelike bodies at the ends of the spindle during mitosis of certain types of cells. (05 Mar 2000) |
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| 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) |
| 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) |
| alveolobuccal sulcus | The upper and lower half of the buccal vestibule on each side. Synonym: alveolobuccal sulcus, gingivobuccal groove, gingivobuccal sulcus. (05 Mar 2000) |
| alveololabial sulcus | The upper and lower half of the labial vestibule, in the embryo, the groove formed by the deepening of the labial sulcus; its inner wall becomes incorporated with the alveolar process of the mandible or the maxilla, and its outer wall with the lips and cheeks. Synonym: alveololabial sulcus, gingivolabial groove, gingivolabial sulcus. (05 Mar 2000) |
| alveololingual sulcus | That part of the oral cavity proper, on each side of the frenulum linguae, between the tongue and the mandibular alveolar process or ridge, in the embryo, the groove on each side between the lingual primordium and the alveolar elevations of the mandible. Synonym: alveololingual sulcus, gingivolingual groove, gingivolingual sulcus. (05 Mar 2000) |
| ampullary sulcus | The groove on the external surface of the ampulla of each saemicircular duct where the nerve enters the crista ampullaris. Synonym: sulcus ampullaris. (05 Mar 2000) |
| anterior intermediate sulcus | A furrow occasionally seen in the adult between the anterior median fissure and the anterior lateral sulcus of the spinal cord but usually present only in the foetus. It indicates the lateral border of the anterior corticospinal fasciculus. Synonym: anterior intermediate groove, sulcus intermedius anterior. (05 Mar 2000) |
| anterior parolfactory sulcus | A fissure marking the anterior border of the parolfactory area. Synonym: sulcus parolfactorius anterior. (05 Mar 2000) |