rod

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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

(rod),
1. A slender cylindric structure or device.
2. The photosensitive, outward-directed process of a rhodopsin-containing rod cell in the external granular layer of the retina; many millions of such rods, together with the cones, form the photoreceptive layer of rods and cones. Synonym(s): rod cell of retina
[A.S. rōd]

rod

(rod)
1. a straight, slim mass of substance.

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

(rŏd)
n.
1. Anatomy Any of various rod-shaped cells in the retina that respond to dim light. Also called rod cell.
2. Microbiology An elongated bacterium; a bacillus.

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.
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Rod

rod

Orthopedics A metal fixation device used to stabilize fractures. See Harrington rod.

rod

(rod)
1. A straight, slender, cylindric structure or device. For surgical rods, see nail;pin
2. The photosensitive, outward-directed process of a rhodopsin-containing rod cell in the external granular layer of the retina; many millions of such rods, together with the cones, form the photoreceptive layer of rods and cones.
Synonym(s): rod cell.
[A.S. rōd]

rod

or

rod cell

a rod-shaped, light-sensitive cell lying in the more peripheral parts of the RETINA in the vertebrate eye. Rods are particularly associated with vision under conditions of low illumination and they occur in large numbers in nocturnal animals. They are not capable of colour discrimination and their visual acuity is poor (compare CONE CELL). RHODOPSIN (visual purple) is found in rods. There are some 240 million rods in the retinas of a primate.see RETINAL CONVERGENCE.

Rod

Photoreceptor that is highly sensitive to low levels of light and transmits images in shades of gray.
Mentioned in: Color Blindness

rod

(rod)
1. A straight, slender, cylindric structure or device.
2. The photosensitive, outward-directed process of a rhodopsin-containing rod cell in the external granular layer of the retina.
[A.S. rōd]

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.
References in periodicals archive ?
Church warden Michael Crick, a civil engineer, said: "For the sake of just a few pounds-worth of copper, the church now has to employ a specialist contractor costing perhaps pounds 2,000 to reinstall a lightning conductor.
Stone Technical Services is working with a range of ecclesiastical organisations as they tackle the increasing problem of the theft of lead, copper and stainless steel roof coverings, roof-flashings, copper lightning conductors and lead rainwater pipes.
It was all a sober warning that sense and sensibility were required when fitting one's lightning conductor.
The thieves removed the section of the lightning conductor cable from the grounding position to just over three metres up the church wall.
But his dad Robert told the inquest in Newry, Co Down: "A lightning conductor could save someone inside the hut.
But there was some good news for the parishioners, left reeling this year when thieves trying to rip the lightning conductor from the spire ended up bringing it crashing down through the roof.
Of Francis and John's remaining siblings, Edward was a distinguished chemist, scholar, philosopher and inventor of the lightning conductor.
Parents Michael, 34, a lightning conductor fitter, and Kirsty, 33, who works in a tanning salon, are distraught.
Sub Head: Building Portion Including Internal Water Supply, Sanitary Installations, Drainage, Internal Electrical Installations, Lightning Conductor, Main Panel And Fire Extinguishers And Miscellaneous
Stone, which also has offices in London and Middlesex, is one of only a handful of companies approved to work on St Paul's Cathedral as an officially-appointed contractor responsible for all structural and high level maintenance repairs and lightning conductor installation.
The money will go towards the cost of repairs at the church, which suffered severe damage in July when thieves after metal tried to rip the lightning conductor from the spire, sending it crashing through the roof.
The firm believes its lightning conductor installation will only increase as climate change becomes a growing concern to the business community.