transitional zone

zone (zōn) an encircling region or area; by extension, any area with specific characteristics or boundary.zo´nal

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ciliary zone  the outer of the two regions into which the anterior surface of the iris is divided by the collarette.

comfort zone  an environmental temperature between 13° and 21°C (55°–70°F) with a humidity of 30 to 55 per cent.

epileptogenic zone  see under focus.

erogenous zone , erotogenic zone an area of the body whose stimulation produces erotic excitation.

inner zone of renal medulla  the part of the medulla farthest in from the cortex, containing ascending and descending limbs of the thin tubule as well as the inner part of the medullary collecting duct.

Lissauer's marginal zone  a bridge of white substance between the apex of the posterior horn and the periphery of the spinal cord.

outer zone of renal medulla  the part of the medulla nearest to the cortex; containing the medullary part of the distal straight tubule as well as the outer part of the medullary collecting duct.

zone of partial preservation  in spinal cord injury, a region where there may be only partial damage to nerves, including one to three spinal segments below the level of the injury.

pellucid zone  zona pellucida.

pupillary zone  the inner of the two regions into which the anterior surface of the iris is divided by the collarette.

transitional zone  any anatomical region that marks the point at which the constituents of a structure change from one type to another.

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transitional zone

n.

1. The region of the lens of the eye where cells from the anterior epithelial capsule become transformed into the fibers that compose the lens substance.

2. The portion of a scleral contact lens that joins the corneal and scleral sections.

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transitional zone

Etymology: L, transire, to go through; Gk, zone, belt

a part of the crystalline lens of the eye where epithelial-capsule cells change into lens fibers.

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zone [zōn]

an encircling region or area; by extension, any area with specific characteristics or boundary.

ciliary zone the outer of the two regions into which the anterior surface of the iris is divided by the collarette.

comfort zone an environmental temperature between 13 and 21°C (55 and 70°F) with a humidity of 30 to 55 per cent.

epileptogenic zone an area, stimulation of which may provoke an epileptic seizure.

erogenous zone (erotogenic zone) in psychoanalytic theory, an area of the body through which the libido expresses itself and which is therefore susceptible to erotic excitation upon stimulation; the primary sites are the oral, anal, and genital regions, but the other body orifices, breasts, and skin are also included.

zone of partial preservation in spinal cord injury, an area of only partial damage that may include up to three consecutive spinal segments caudal to the level of the injury.

pupillary zone the inner of the two regions into which the anterior surface of the iris is divided by the collarette.

transition zone (transitional zone) any anatomical region that marks the point at which the constituents of a structure change from one type to another; for example, the circle in the equator of the ocular lens in which epithelial fibers are developed into lens fibers, or the zone (anocutaneous line) that marks the junction of stratified squamous epithelium with columnar epithelium.

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zone

an encircling region or area; by extension, any area with specific characteristics or boundary. See also zona.

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autonomous innervation zone

areas of innervation supplied by a single nerve, as for example the patch of skin on the medial side of the horse fore pastern which is supplied solely by the median nerve; used to assess the integrity of individual nerves.

ciliary zone

the outer of the two regions into which the anterior surface of the iris is divided by the angular line.

comfort zone

an environmental temperature between 55° and 70° F (13° and 21° C) with a humidity of 30 to 55%.

epileptogenic zone

an area, stimulation of which may provoke an epileptic seizure.

zone of inhibition

the area without bacterial growth surrounding an antimicrobial-impregnated disk in an antimicrobial sensitivity test.

provisional calcification zone

in developing bone longitudinal tubes of mineralized matrix which surround hypertrophic chondrocytes.

transitional zone

the circle in the equator of the lens of the eye in which epithelial fibers are developed into lens fibers.