chorionic villus

villus /vil·lus/ (vil´us) pl. vil´li   [L.] a small vascular process or protrusion, especially from the free surface of a membrane.

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arachnoid villi 

1. microscopic projections of the arachnoid into some of the venous sinuses.

2. arachnoidal granulations.

chorionic villus  one of the threadlike projections growing in tufts on the external surface of the chorion.

intestinal villi  multitudinous threadlike projections covering the surface of the mucous membrane lining the small intestine, serving as the sites of absorption of fluids and nutrients.

Intestinal villus.

synovial villi  slender projections of the synovial membrane from its free inner surface into the joint cavity.

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chorionic villus

n.

Any of the various fingerlike projections of the chorion of the embryo that contain fetal blood vessels and grow into the intervillous lacuna of the placenta.

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chorionic villus

Etymology: Gk, chorion + L, villus, shaggy hair

any of the tiny vascular fibrils on the surface of the chorion that infiltrate the maternal blood sinuses of the endometrium and help form the placenta.

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villus

pl. villi [L.] a small process or protrusion, as from the free surface of a membrane.

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arachnoid villus

microscopic projections of the arachnoid into some of the venous sinuses. Called also arachnoid granulations.

chorionic villus

threadlike projections originally occurring uniformly over the external surface of the chorion.

intestinal villus

multitudinous threadlike projections covering the surface of the mucous membrane lining the small intestine, serving as the sites of absorption of fluids and nutrients.

Organization of an intestinal villus. By permission from Guyton R, Hall JE, Textbook of Medical Physiology, Saunders, 2000

synovial villus

slender projections from the surface of the synovial membrane into the cavity of a joint; called also haversian glands.