1. A figure having a circular base with sides inclined so as to meet at a point above. 2. The photosensitive, outward-directed, conical process of a c. cell essential for sharp vision and color vision; c.'s are the only photoreceptor in the fovea centralis and become interspersed with increasing numbers of rods toward the periphery of the retina.cone cell of retina; 3. Metallic cylinder or c. used to confine a beam of x-rays.conus (1); [G. konos, cone]
antipodal c. the set of astral rays of a dividing cell extending from the centriole in a direction opposite to the equatorial plate.
arterial c. conus arteriosusinfundibulum (4);
c. down to narrow a beam of x-rays to a region of interest using a collimator or c. (3); colloq., to delimit one's attention or activities.
elastic c. conus elasticus (1)
gutta-percha c. a c.-shaped, semirigid root canal filling material composed of gutta-percha and zinc oxide.
Haller's c.'s lobules of epididymis, under lobule
implantation c. axon hillock
keratosic c.'s obsolete term for horny pointed or rounded elevations on the hands and feet, occasionally observed in cases of gonorrheal rheumatism.
c. of light pyramid of light
medullary c. the tapering lower extremity of the spinal cord.conus medullaris [NA];
nerve growth c. a highly motile structure at the leading edge of an elongating axon.
ocular c. the c. of light in the interior of the eyeball with the base formed by the rays entering through the pupil and the apex focused on the retina.
Politzer's luminous c. pyramid of light
pulmonary c. conus arteriosus
retinal c.'s See cone (2).
silver c. pure silver c. with standard conical shape, used with cement to obturate dental root canals.
theca interna c. the conical thickening of thecal cells of an ovarian follicle with its apex pointed toward the surface.
twin c. two retinal c.'s fused together.
vascular c.'s lobules of epididymis, under lobule
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