Arrector pili is a small, involuntary muscle composed of smooth muscle cell. It attaches to the hair bulb of the hair follicle and act to pull the hair up during cold or emotional distress, forming the “goose bump” on skin surface.


Arrector pili is a small, involuntary muscle composed of smooth muscle cell. It attaches to the hair bulb of the hair follicle and act to pull the hair up during cold or emotional distress, forming the “goose bump” on skin surface.