Rod
A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides side vision and the ability to see objects in dim light (night vision). By contrast, the cones are the retinal photoreceptors that provide sharp central vision and color vision.
* * *
1. A slender cylindric structure or device. 2. The photosensitive, outward-directed process of a rhodopsin-containing r. 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. SYN: r. cell of retina. [A.S. r.]
- analyzing r. a device used with a surveyor to determine the relative positions of parallel surfaces and undercuts when designing removable partial dentures.
- Auer rods SYN: Auer bodies, under body.
- basal r. SYN: costa (2).
- Corti rods SYN: pillar cells, under cell.
- enamel rods SYN: prismata adamantina, under prisma.
- germinal r. SYN: sporozoite.
- Maddox r. a glass r., or a series of parallel glass rods, that converts the image of a light source into a streak of light perpendicular to the axis of the r.. The position of this streak in relation to the image of the light source seen by the fellow eye indicates the presence and amount of heterophoria.
- surgical r. a cylindric implant, usually composed of metal, used to align and internally fix fractures of long bones. SEE ALSO: nail, pin.
* * *
record of decision

* * *

rod 'räd n
1) a straight slender pole or bar
2) any of the long rod-shaped photosensitive receptors in the retina responsive to faint light compare CONE (2a)
3) a bacterium shaped like a rod

* * *

n.
one of the two types of light-sensitive cells in the retina of the eye (compare cone). The human eye contains about 125 million rods, which are necessary for seeing in dim light. They contain a pigment, rhodopsin (or visual purple), which is broken down (bleached) in the light and regenerated in the dark. Breakdown of visual purple gives rise to nerve impulses; when all the pigment is bleached (i.e. in bright light) the rods no longer function. See also dark adaptation, light adaptation.

* * *

(rod) 1. a straight, slim mass of substance. 2. retinal r.

Medical dictionary. 2011.

Synonyms:

Look at other dictionaries:

  • Rod — may mean: *Rod (geometry), a straight and slender stick; a wand; a cylinder; hence, any slender bar *Rod cell, a cell found in the retina that is sensitive to light/dark (black/white) *Rod (length), an Imperial unit of length, also known as the… …   Wikipedia

  • rod — rȏd m <G rȍda, N mn ròdovi> DEFINICIJA 1. a. ono što je rođeno; porod, potomstvo, vrsta b. obitelj, obiteljska loza, soj c. rodbina, srodnici (ob. krvni, po ocu i majci) d. svojta [biti rod] 2. urod, plod, plodovi (voća, krumpira) 3. a.… …   Hrvatski jezični portal

  • Rod — bezeichnet: eine Längeneinheit, siehe Rute (Einheit) ein altdeutsches Wort (auch Rodt) für die Stelle einer Rodung zum Zwecke der Felderweiterung oder Siedlung einen Hot Rod, ein speziell getunter Oldtimer die Ausführung aus massivem Metall… …   Deutsch Wikipedia

  • Rod — /rod/, n. a male given name, form of Roderick or Rodney. * * * (as used in expressions) Carew Rod eccentric and rod mechanism hot rod * * * ▪ measurement       old English measure of distance equal to 16.5 feet (5.029 metres), with variations… …   Universalium

  • rod — ROD, roade, s.n. 1. Nume generic dat produselor vegetale obţinute de la plantele cultivate, în special fructelor; fruct. ♢ loc. adj. Cu rod = roditor, fructifer. ♢ Compuse: rodul pământului = plantă erbacee veninoasă, cu frunze mari, late şi… …   Dicționar Român

  • rod — [rɔd US ra:d] n [: Old English; Origin: rodd] 1.) a long thin pole or bar steel/iron/wooden etc rod ▪ The walls are reinforced with steel rods. ▪ a measuring rod ↑basket, ↑net, ↑reel, ↑rod 2.) …   Dictionary of contemporary English

  • Rod — Saltar a navegación, búsqueda El término Rod puede tener diferentes significados: Unidad de medida anglosajona (Unidad longitud Rod) Rod (criptozoología y ufología), supuestos fenómenos o criaturas pseudocríptidas. Siglas de una serie de novelas… …   Wikipedia Español

  • rod — ► NOUN 1) a thin straight bar, especially of wood or metal. 2) a fishing rod. 3) a slender straight stick or shoot growing on or cut from a tree or bush. 4) (the rod) the use of a stick for caning or flogging. 5) Anatomy one of two types of light …   English terms dictionary

  • rod — [räd] n. [ME rodde < OE rodd, akin to ON rudda, club, prob. < IE base * rēt , *rōt , bar, beam > L retae, trees on a river bank] 1. a straight, slender shoot or stem cut from, or still part of, a bush or tree 2. Bible an offshoot or… …   English World dictionary

  • Rod — Rod, n. [The same word as rood. See {Rood}.] 1. A straight and slender stick; a wand; hence, any slender bar, as of wood or metal (applied to various purposes). Specifically: (a) An instrument of punishment or correction; figuratively,… …   The Collaborative International Dictionary of English

  • rôd — m 〈G rȍda, N mn ròdovi〉 1. {{001f}}a. {{001f}}ono što je rođeno; porod, potomstvo, vrsta b. {{001f}}obitelj, obiteljska loza, soj c. {{001f}}rodbina, srodnici (ob. krvni, po ocu i majci) d. {{001f}}svojta [biti ∼] 2. {{001f}}urod, plod, plodovi… …   Veliki rječnik hrvatskoga jezika

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”