venous (redirected from scleral venous plexus)

venous /ve·nous/ (ve´nus) pertaining to the veins.

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ve·nous (vns)

adj.

Of, relating to, or contained in the veins.

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venous.

See vein.

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vein [vān]

a vessel through which blood passes from various organs or parts back to the heart, in the systemic circulation carrying blood that has given up most of its oxygen. Veins, like arteries, have three coats: an inner coat (tunica intima), middle coat (tunica media), and outer coat (tunica externa); however, in veins these are less thick and collapse when the vessel is cut. Many veins, especially superficial ones, have valves formed of reduplication of their lining membrane. See Appendix 2-6 and see also Plates.

afferent v's veins that carry blood to an organ.

allantoic v's paired vessels that accompany the allantois, growing out from the primitive hindgut and entering the body stalk of the early embryo.

cardinal v's embryonic vessels that include the pre- and postcardinal veins and the ducts of Cuvier (common cardinal veins).

emissary vein one passing through a foramen of the skull and draining blood from a cerebral sinus into a vessel outside the skull. See anatomic Table of Veins in the Appendices.

postcardinal v's paired vessels in the early embryo that return blood from regions caudal to the heart.

precardinal v's paired venous trunks in the embryo cranial to the heart.

pulp v's vessels draining the venous sinuses of the spleen.

subcardinal v's paired vessels in the embryo, replacing the postcardinal veins and persisting to some degree as definitive vessels.

sublobular v's tributaries of the hepatic veins that receive the central veins of hepatic lobules.

supracardinal v's paired vessels in the embryo developing later than the subcardinal veins and persisting chiefly as the lower segment of the inferior vena cava.

thebesian v's smallest cardiac veins; see anatomic Table of Veins in the Appendices.

trabecular v's vessels coursing in splenic trabeculae, formed by tributary pulp veins.

varicose v's see varicose veins.

vitelline v's veins that return the blood from the yolk sac to the primitive heart of the early embryo.

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venous

pertaining to the veins.

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venous dilatation

persistent dilatation of the vein but without necessarily any weakening of the wall or varicosity.

hepatic portal venous system

includes the veins from the alimentary tract, the portal vein, the sinusoids in the liver, the hepatic veins and then the entry into the caudal vena cava.

venous infarct

see venous infarct.

obstructed venous drainage

may be generalized or local; manifested by dilation, local edema.

orbital venous plexus

a plexus for venous drainage from the ophthalmic veins at the apex of the orbit; drains into the cavernous venous sinus within the cranium.

venous return

the flow of blood into the heart from the peripheral vessels.

venous return curves

relate venous return to atrial pressure; the inverse of the Starling relationship; an increase in atrial pressure decreases the venous return.

scleral venous plexus

a ring of small vessels around the corneal limbus which forms a link in the chain of vessels which drain the aqueous humor. Called also canal of Schlemm.

venous sinuses

see venous sinus.

venous system

the bodily system of veins commencing with the venae cavae, thence through the large veins and their tributaries, and immediately subsequent to the capillaries, the venules.

venous thrombosis

the presence of a thrombus in a vein. Originates in phlebitis in most cases. It is a major problem in horses because of the high incidence of jugular phlebitis and periphlebitis as a result of injection of irritating materials. See also caudal vena caval thrombosis.

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Patient discussion about venous.

Q. I drink liquor a lot maybe 4x a week and I love drinking but after a couple days my veins star to hurt...Y? It runs in the familly alcohol and bud but I wish I could go a whole year withought poppin bottles.. what will be perscibed to a alki?

A. your veins start to hurt cause you drink to much so try cutting off a little bit and see how it turns out

Q. Are long flights dangerous? I'm flying next week to my vacation, and the flight is going to be rather long (almost 16 hours non-stop). Several years ago, my 75 years-old aunt had blood clot in her lung after a flight of similar length. I also heard that during flight the blood in the legs clots and that it can cause after that problems with the lungs and breathing. Does this mean it's dangerous for me to fly? Should I change my ticket to shorter connection flights?

A. Long flights, especially when seating in crowded cabins without moving the legs for long periods can cause the blood in you legs to clot and after that to move to your lungs and damage them. You may try to move your legs during the flights (like getting up and walking a little etc.) This video has some suggestions:
http://youtube.com/watch?v=_mte4WsVZUk