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A hair that burrows into the skin.
See also: pilus
pl. pili [L.]
1. a hair.
2. fine, filamentous appendage found on the surface of many gram-negative bacteria, shorter, thinner and straighter than flagella. There are two kinds of pili: (a) a larger form that is hollow and found on male bacterial cells only; it is used in bacterial cell conjugation, and (b) a smaller form which is of major significance in adherence of bacterial cells to epithelial surfaces such as the intestinal mucosa or mammary gland epithelium. Antipilus antibody can provide protection against disease. Called also fimbria.
pl. pili cuniculati; burrowing hair.
pl. pili incarnati; ingrown hair.
tactile hairs about the lips, nostrils and eyes.
pl. pili torti; twisted hair; see also pili torti.