rod (rod)
Rod
rod 
rod [rod]
rod,
rod
1. a straight, slim mass of substance.
2. retinal rod
Corti's rods pillar cells.
enamel rods the approximately parallel rods or prisms forming the enamel of the teeth.
olfactory rod the slender apical portion of an olfactory bipolar neuron, a modified dendrite extending to the surface of the epithelium.
retinal rod a specialized cylindrical segment of the visual cells containing rhodopsin; the rods serve night vision and detection of motion, and together with the retinal cones form the light-sensitive elements of the retina.
rod (r d)n. 1. A straight slender cylindrical formation. 2. A rod cell. 3. An elongated bacterium; a bacillus. |
Rod
Photoreceptor that is highly sensitive to low levels of light and transmits images in shades of gray.
Mentioned in: Color Blindness
rod
Etymology: AS, rodd
1 a straight cylindric structure.
2 one of the tiny cylindric elements arranged perpendicular to the surface of the retina. Rods contain the chemical rhodopsin, which adapts the eye to detect low-intensity light and gives the rods a purple color. Each rod is 40 to 60 μm in length and about 2 μm thick and consists of a slender reactive outer segment and an inner granular segment. When bright light strikes a rod, rhodopsin rapidly breaks down; it reforms gradually in low-intensity light. Compare cone. See also iodopsin, Jacob x membrane, rhodopsin.
)
Rod
rod [rod]
1. a straight, slim mass of substance.
2. one of two types of visual cells, cylindrical segments that contain rhodopsin; together with the cones they form the light-sensitive elements of the retina. See also eye and vision. Called also retinal rod.
Corti's r's pillar cells.
Harrington rod a rigid contoured metal rod used in Harrington instrumentation.
olfactory rod the slender apical portion of an olfactory bipolar neuron, a modified dendrite extending to the surface of the epithelium.
retinal rod rod (def. 2).
rod,
n a straight, slim, cylindric form of material, usually metal.
rod, analyzing,
n the vertical part of a dental cast surveyor that is brought into contact with the surface contour of a tooth as a tangent related to a curve. It is used to determine the relative parallelism of one surface of a cast to other surfaces of the same cast. It is also used to estimate the cervical convergence of an infrabulge area of a tooth as it slopes from the contacting point of the surveying rod toward the cervical line, permitting evaluation of the retentiveness of the surface.
rod, condyle,
n the adjustable pointers of a face-bow, which are placed over the condyles or at points on the face to mark the opening axis of the mandible.
rod, enamel,
n a calcified column or prism, with an average diameter of 4 microns; extends in a wavy pattern through the entire thickness of the enamel and is generally perpendicular to the surface of the tooth.
rod
a straight, slim mass of substance; specifically, one of the retinal rods; are highly specialized cylindrical segments of the neuroepithelial visual cells containing rhodopsin and modified to receive, transduce and transmit visual stimuli; together with the retinal cones, they form the light-sensitive elements of the retina. See also cone (1).
rod-cone dysplasia
an inherited defect in dogs, particularly Irish setters, Elkhounds and Miniature poodles, causing a progressive retinal atrophy with impairment of night vision, then day vision starting at an early age. There are differences in the ultrastructural and biochemical features in each breed, but generally rods are more severely affected than cones. See also progressive retinal atrophy.
olfactory rod
the slender apical portion of an olfactory bipolar neuron, a modified dendrite extending to the surface of the epithelium.
rod
Orthopedics A metal fixation device used to stabilize fractures. See Harrington rod.
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