| vegetal pole | Of vertebrate eggs. The surface of the egg opposite to the animal pole. Usually the cytoplasm in this region is incorporated into future endoderm cells. (18 Nov 1997) |
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| vegetative pole | The part of a telolecithal egg where the bulk of the yolk is situated. (05 Mar 2000) |
| germinal pole | <cell biology> In most animal oocytes the nucleus is not centrally placed and its position can be used to define two poles. That nearest to the nucleus is the animal pole and the other is the vegetal pole, with the animal vegetal axis between the poles passing through the nucleus. During meiosis of the oocyte the polar bodies are expelled at animal pole. In many eggs there is also a graded distribution of substances along this axis, with pigment granules often concentrated in the animal half and yolk, where present, largely in the vegetal half. (12 Nov 1997) |
| medial pole of ovary | The rounded medial end of the ovary, usually directed toward the uterus. Synonym: extremitas uterina ovarii, medial pole of ovary. (05 Mar 2000) |
| cephalic pole | The head end of the foetus. (05 Mar 2000) |
| pole | 1. A long, slender piece of wood; a tall, slender piece of timber; the stem of a small tree whose branches have been removed; as, specifically: A carriage pole, a wooden bar extending from the front axle of a carriage between the wheel horses, by which the carriage is guided and held back. A flag pole, a pole on which a flag is supported. A Maypole. See Maypole. A barber's pole, a pole painted in stripes, used as a sign by barbers and hairdressers. A pole on which climbing beans, hops, or other vines, are trained. 2. A measuring stick; also, a measure of length equal to 5 yards, or a square measure equal to 30 square yards; a rod; a perch. <botany> Pole bean, a horizontal timber resting on the tiebeams of a roof and receiving the ends of the rafters. It differs from the plate in not resting on the wall. Origin: As. Pal, L. Palus, akin to pangere to make fast. Cf. Pale a stake, Pact. 1. Either extremity of an axis of a sphere; especially, one of the extremities of the earth's axis; as, the north pole. 2. <geometry> A point upon the surface of a sphere equally distant from every part of the circumference of a great circle; or the point in which a diameter of the sphere perpendicular to the plane of such circle meets the surface. Such a point is called the pole of that circle; as, the pole of the horizon; the pole of the ecliptic; the pole of a given meridian. 3. <physics> One of the opposite or contrasted parts or directions in which a polar force is manifested; a point of maximum intensity of a force which has two such points, or which has polarity; as, the poles of a magnet; the north pole of a needle. 4. The firmament; the sky. "Shoots against the dusky pole." (Milton) 5. <geometry> See Polarity, and Polar, Magnetic pole. See Magnetic. <geography> Poles of the earth, or Terrestrial poles, the two opposite points on the earth's surface through which its axis passes. Poles of the heavens, or Celestial poles, the two opposite points in the celestial sphere which coincide with the earth's axis produced, and about which the heavens appear to revolve. Origin: L. Polus, Gr. A pivot or hinge on which anything turns, an axis, a pole; akin to to move: cf. F. Pole. Source: Websters Dictionary (01 Mar 1998) |
| pole cell | <cell biology> A cell at or near the animal or vegetal pole of an embryo. (18 Nov 1997) |
| pole fibre | <cell biology> Microtubules inserted into the pole regions of the mitotic spindle (each pole is the product of the division of the centrioles and constitutes a microtubule organising centre. (18 Nov 1997) |
| pole ligation | A ligation at the root of an organ to shut off or diminish blood supply. (05 Mar 2000) |
| posterior pole of eyeball | The centre of the posterior curvature of the eye. Synonym: polus posterior bulbi oculi. (05 Mar 2000) |
| posterior pole of lens | The central point on the posterior surface of the lens. Synonym: polus posterior lentis. (05 Mar 2000) |
| superior pole | For a structure having a vertically oriented long axis, the point at the upper end of the axis, furthest from the soles of the feet; the highest point of a structure's surface. See: superior pole of kidney, superior pole of testis. Synonym: extremitas superior, superior extremity. (05 Mar 2000) |
| superior pole of kidney | The superior end of the kidney. Synonym: extremitas superior renis. (05 Mar 2000) |
| superior pole of testis | The superior end of the testis. Synonym: extremitas superior testis. (05 Mar 2000) |
| inferior pole | For a structure having a vertically-oriented long axis, the point at the lower end of the axis, nearest the soles of the feet; the lowest point of a structure's surface. See: inferior pole of kidney, inferior pole of testis. Synonym: extremitas inferior, inferior extremity. (05 Mar 2000) |