Noun
arrector (plural arrectores)
Synonym of erector
In humans, the skin hairs lie flat in hot conditions, as the arrector pili muscles relax, preventing heat from being trapped by a layer of still air between the hairs, and increasing heat loss by convection. Source: Internet
Fingers do not contain muscles (other than arrector pili ). Source: Internet
The skin along the middle of the dorsal side is folded in, and covered with convert white hair erected by arrector pili muscles (located between hair follicles ). Source: Internet
When the body is too cold, the arrector pili muscles found attached to hair follicles stand up, causing the hair in these follicles to do the same. Source: Internet
The opposite actions occur when the body is too warm; the arrector muscles make the hair lie flat on the skin which allows heat to leave. Source: Internet