(zōn )

[L. zona, fr. Gr. zōnē, a girdle]

ABBR: z

1. An area or belt.
2. A lobe of an organ or a gland .

anal transition z.

ABBR: ATZ

border z.The partially damaged portion of an organ that is found between tissue that is severely injured by an infarct and nearby tissue but is still well supplied with blood, oxygen, and nutrients.

care z.During a public health care emergency, the areas where specialized protections are kept to prevent the spread of disease or contamination. The zones are designated hot, warm, cold and vary in their requirements for personal protective equipment, isolation procedures, air and /or water filtration, waste disposal, communications, and control of entry and exit by health care personnel.

A hot zone is where the hazardous materials are located; this area cannot be entered without protective equipment, special permission, and specialized training.

A warm zone is an area between the hot zone and the cold zone, where decontamination occurs. Only specialized personnel who are appropriately dressed are permitted in this location.

A cold zone is an unexposed area, safe from any potential contamination, where the command post is located and where rescue personnel wait for assignments.

cell-free z.In dentistry, an zone below the odontoblastic layer of the dental pulp that has relatively few cells. SYN: zone of Weil.

cell-rich z.The zone of increased cell frequency between the cell-free zone and the central pulp of the tooth.

chemoreceptor trigger z.

ABBR: CTZ

coagulation z.In a burn wound, the central zone of necrotic tissue.

ciliary z.The peripheral annular zone of the anterior surface of the iris of the eye. The ciliary zone is separated from the inner, more narrow annulus, the pupillary zone, of the iris by a wavy boundary, the collarette. These regions are used in automated iris recognition technology.

cold z.

SEE: care zone.

comfort z.The range of temperature, humidity, and , when applicable, solar radiation and wind in which an individual doing work at a specified rate and in a certain specified garment is comfortable.

epileptogenic z.Any zone of the brain that after stimulation produces an epileptic seizure.

erogenous z.A zone of the body that may produce erotic sensations when stimulated. These areas include, but are not limited to, the breasts, lips, genital and anal regions, buttocks, and sometimes the special senses that cause sexual excitation, such as the sense of smell or taste.

H z.H band .

hot z.

SEE: care zone.

z. of hyperemia In a burn wound, a zone with increased blood circulation.

hypnogenic z.Any zone of the body that, when pressed on, induces hypnosis. SYN: hypnogenic spot.

Looser z.s

SEE: Looser zones.

lung z.A hypothetical zone of the lung defined by the relationship between the degree of alveolar ventilation and pulmonary blood flow (perfusion). Three lung zones have been identified: I) ventilation exceeds perfusion; II) ventilation and perfusion are equal; and III) perfusion exceeds ventilation. Zone I is found in the upper lung field, where gravity impedes perfusion, and zone III in the inferior portion of the lung, where gravity assists perfusion.

z. of partial preservation In a complete spinal cord injury, a zone of partial sparing of motor and /or sensory function above the level of the lowest sacral segment (S5) and below the level of injury.

pellucid z.Zona pellucida.

peripheral z.

ABBR: PZ

peripheral z. of the prostate Peripheral zone.

pupillary z.The innermost of two annular zones visible on the anterior surface of the iris.

SEE: ciliary zone.

root z.Fasciculus cuneatus.

z. of stasis In a burn wound, the zone of skin beneath the coagulated surface in which blood flow is diminished and tissue fluid collects. This zone may become necrotic if it becomes infected or fails to receive adequate blood flow.

transition z.1A zone of tissue that includes two or more cell types linking two distinct regions of an organ.2Squamocolumnar junction.

transition z. of the prostate

Variant: transitional zone of the prostate