| ependymal zone | An inner epithelial layer of cells bordering the lumen of the embryonic neural tube and brain, formed during the latter's stratification, and persisting in modified form throughout life. Synonym: ependymal zone, ventricular layer. (05 Mar 2000) |
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| epileptogenic zone | A cortical region which on stimulation reproduces the patient's spontaneous seizure or aura. (05 Mar 2000) |
| trigger zone | Dolorogenic zone (= producing or causing pain). (18 Nov 1997) |
| equivalence zone | In a precipitin reaction, the zone in which neither antibody nor antigen is in excess. See: precipitation. Synonym: equivalence point. (05 Mar 2000) |
| erogenous zone | An erotogenic zone, areas of the body, such as genitals and nipples, which elicit sexual arousal when stimulated. (05 Mar 2000) |
| trophotropic zone of Hess | An area in the hypothalamus concerned with rewarding bodily sensations. (05 Mar 2000) |
| trummerfeld scurvy zone | <radiology> Lucent band in metaphysis beneath white line of Frankel, seen in scurvy (12 Dec 1998) |
| zone | 1. A girdle; a cincture. "An embroidered zone surrounds her waist." (Dryden) "Loose were her tresses seen, her zone unbound." (Collins) 2. <geography> One of the five great divisions of the earth, with respect to latitude and temperature. The zones are five: the torrid zone, extending from tropic to tropic 46 deg 56 min, or 23 deg 28 min on each side of the equator; two temperate or variable zones, situated between the tropics and the polar circles; and two frigid zones, situated between the polar circles and the poles. "Commerce . . . Defies every wind, outrides every tempest, and invades." (Bancroft) 3. <mathematics> The portion of the surface of a sphere included between two parallel planes; the portion of a surface of revolution included between two planes perpendicular to the axis. 4. A band or stripe extending around a body. A band or area of growth encircling anything; as, a zone of evergreens on a mountain; the zone of animal or vegetable life in the ocean around an island or a continent; the Alpine zone, that part of mountains which is above the limit of tree growth. 5. <chemistry> A series of planes having mutually parallel intersections. 6. Circuit; circumference. Abyssal zone. To girdle; to encircle. <physics> A straight line passing through the center of a crystal, to which all the planes of a given zone are parallel. Origin: F. Zone, L. Zona, Gr.; akin to to gird, Lith. Jsta to gird, Zend yah. Source: Websters Dictionary (01 Mar 1998) |
| zone 1, 2, 3, 4 of West | In pulmonary physiology, defines the levels in a vertical lung according to the relationships of alveolar gas pressure, capillary blood pressure, and pulmonary venous pressure. (05 Mar 2000) |
| zone centrifugation | <technique> High-speed centrifugation inwhich molecules float at a point wheretheir density equals that in a gradient of cesium chloride or sucrose. (12 Jan 1998) |
| zone electrophoresis | <chemistry, procedure> A type of electrophoresis used by physical chemists. In it, the components of a mixture are separated into distinct zones by moving the solution through a porous medium such as filter paper. (06 May 1997) |
| zone of inhibition | <microbiology> The area of no bacterial browth around an antimicrobial agent in the disk-diffusion test. (09 Oct 1997) |
| zone of optimal proportion | <chemistry> A zone in a solution of mixed antigen in which the two biomolecules are totally combined. (11 May 1997) |
| foetal zone | An extensive area of the adrenal gland present in primates during foetal life and for a short period after birth; located between the definitive cortex and the medulla, it contains large steroid-secreting cells arranged in a reticular pattern; involution of this zone in humans is largely completed by three months after birth. Synonym: androgenic zone, foetal reticularis, foetal zone, provisional cortex. (05 Mar 2000) |
| language zone | A large area of the cerebral cortex on the left side (in right-handed persons) considered by some to embrace all the centres of memories and associations connected with language. (05 Mar 2000) |