arrector pili(redirected from Arrectores pilorum)
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arrector pili(ă-rek′tŏr pī′lī″, pil′ē) (ar″ek′tōr′ēz pī″lōr′ŭm, pil-ōr′) plural.arrectores pilorum [L. arrector, raiser + pilus]
One of the involuntary muscle fibers arising in the skin and extending down to connect with the hair follicles on the side toward which the hair slopes. After certain stimuli, including cold or fright, the muscle fibers contract, straighten the follicles, and raise the hairs, resulting in piloerection.