- - altitude c. a decompression c. for simulating a high altitude environment, particularly its low barometric pressure. SYN: high altitude c..- anechoic c. a room designed to absorb all sound so as to eliminate all echoes; used for research on hearing and sensory deprivation.- anterior c. of eyeball [TA] the space between the cornea anteriorly and the iris/pupil posteriorly, filled with a watery fluid (aqueous humor) and communicating through the pupil with the posterior c.. SYN: camera anterior bulbi [TA], camera (1) [TA], camera oculi anterior, camera oculi major.- aqueous chambers the combined anterior and posterior chambers of the eye containing the aqueous humor. See anterior c. of eyeball, posterior c. of eyeball. SEE ALSO: anterior segment.- counting c. a device for counting microscopic objects suspended in fluid, as cells and platelets in dilute whole blood or bacteria in broth culture. It consists of a microscope slide containing a shallow cavity of uniform depth whose floor is ruled with a grid and which, when closed with a cover glass, holds a precise volume of fluid. A calculation based on the number of objects counted within the grid lines, the dilution of the fluid, and the volume of the counting c. yields an estimate of the concentration of objects in the fluid before dilution. SEE ALSO: hemocytometer.- chambers of eyeball [TA] the cavities within the eyeball : anterior and posterior chambers, filled with aqueous, and the postremal (vitreous) c., occupied by the vitreous. SEE ALSO: anterior c. of eyeball, posterior c. of eyeball, postremal c. of eyeball. SYN: camerae bulbi [TA].- high altitude c. SYN: altitude c..- hyperbaric c. a c. providing pressures greater than atmospheric, commonly used to treat decompression sickness and to provide hyperbaric oxygenation.- ionization c. a c. for detecting ionization of the enclosed gas; used for determining intensity of ionizing radiation. SEE ALSO: Geiger-Müller counter.- posterior c. of eyeball the ringlike space, filled with aqueous humor, between the iris/pupil anteriorly and the lens and ciliary body posteriorly. SYN: camera posterior bulbi [TA], camera oculi minor, camera oculi posterior.- postremal c. of eyeball [TA] the large space between the lens and the retina; it is filled with the vitreous body. SYN: camera postrema [TA], camera vitrea bulbi, camera vitrea, vitreous c., posterior segment of eyeball, vitreous camera, vitreous c. of eye.- relief c. a recess in the impression surface of a denture to reduce or eliminate pressure from that specific area of the mouth.- Sandison-Clark c. a c. that can be fitted over a hole punched in a rabbit's ear, so that tissue will grow to fill the defect between two transparent plates; if the distance between the plates is small, the living tissue can be studied microscopically.- sinuatrial c. the common c. formed by the single embryonic atrium and the right and left horns of the sinus venosus.- Zappert counting c. a special, standardized glass slide used for counting cells (especially erythrocytes and leukocytes) and other particulate material in a measured volume of fluid; the central portion is precisely ground in such a manner that the uniformly flat surface is exactly 0.1 mm lower than that of two parallel ridges on which a special, uniformly flat coverslip may be placed; accurately etched lines on the flat central portion form the boundaries of groups of squares of known areas, thereby providing the basis for determining the volume of fluid in which the cells are counted. Glass slides of this type are frequently known as hemocytometers.
* * *cham·ber 'chām-bər n an enclosed space within the body of an animal see ANTERIOR CHAMBER, POSTERIOR CHAMBER
* * *cham·ber (chāmґbər) [L. camera; Gr. kamara] an enclosed space or antrum.
Medical dictionary. 2011.