What is the function of the arrector pili muscle?

What is the function of the arrector pili muscle?

• A. To regulate hair color.
• B. To produce sebum.
• C. To anchor hair to follicle.
• D. To cause hair to stand up (goosebumps) in response to cold or fear. Involuntary movement.

Answer: (D)

Arrector pili are tiny smooth muscles attached to each hair follicle. They contract when the body is exposed to cold or experiences fear, under the control of the sympathetic nervous system. This voluntary-involuntary movement pulls the hair upright, producing goosebumps. It’s an automatic response, not related to hair color, sebum production, or the way hair is anchored in the follicle.

Arrector pili are tiny smooth muscles attached to each hair follicle. They contract when the body is exposed to cold or experiences fear, under the control of the sympathetic nervous system. This voluntary-involuntary movement pulls the hair upright, producing goosebumps. It’s an automatic response, not related to hair color, sebum production, or the way hair is anchored in the follicle.