ANATOMY

Detailed explanation-1: -The arrector pili muscle (APM) consists of a small band of smooth muscle that connects the hair follicle to the connective tissue of the basement membrane. The APM mediates thermoregulation by contracting to increase air-trapping, but was thought to be vestigial in humans.

Detailed explanation-2: -Hair Erector Muscle (Arrector Pili Muscle) The arrector pili muscle is a tiny muscle connected to each hair follicle and the skin. When it contracts it causes the hair to stand erect, and a “goosebump” forms on the skin.

Detailed explanation-3: -Arrector pili muscles are enwrapped by sympathetic pilomotor nerves, which release the neurotransmitter norepinephrine (NE) to trigger muscle contraction and cause hairs to become erect in response to cold.

Detailed explanation-4: -Goosebumps. Have you ever wondered why the hair on your neck or arms stands up when you’re scared or cold? It’s because of smooth muscles in your skin called “arrector pili.” These smooth muscles pull your hair follicles to stand up when you feel afraid or cold.

Detailed explanation-5: -Goosebumps occur when tiny muscles in our skin’s hair follicles, called arrector pili muscles, pull hair upright.