Definitions for villusˈvɪl əs; ˈvɪl aɪ
This page provides all possible meanings and translations of the word villus
Random House Webster's College Dictionary
vil•lusˈvɪl əs; ˈvɪl aɪ(n.)(pl.)vil•li
any of the fingerlike projections on the surface of certain membranes, esp. on the mucous membrane of the small intestine, functioning to increase the area for the absorption, secretion, or exchange of materials.
any of the long, soft, straight hairs covering the fruit, flowers, and other parts of certain plants.
Origin of villus:
1695–1705; < L: shaggy hair, thick nap
a minute hairlike projection on mucous membrane
a small projection from a mucous membrane, particularly those found in the intestines
one of the minute papillary processes on certain vascular membranes; a villosity; as, villi cover the lining of the small intestines of many animals and serve to increase the absorbing surface
fine hairs on plants, resembling the pile of velvet
Intestinal villi are small, finger-like projections that protrude from the epithelial lining of the intestinal wall. Each villus is approximately 0.5-1.6 in length and has many microvilli, each of which are much smaller than a single villus. The intestinal villi should not be confused with the larger folds of mucous membrane in the bowel known as the plicae circulares. A villus is much smaller than a single fold of plicae circulares. Villi increase the internal surface area of the intestinal walls. Increased surface area allows for increased intestinal wall area that is available for absorption. Increased absorptive area is useful because digested nutrients pass into the semipermeable villi through diffusion, which is effective only at short distances. In other words, increased surface area decreases the average distance travelled by nutrient molecules, so effectiveness of diffusion increases. The villi are connected to the blood vessels so the circulating blood then carries these nutrients away.
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