Redseal Hairstyling License Practice Test

What is the function of the arrector pili muscle?

1. To control hair color

2. To support hair growth

3. To elevate hair and create goosebumps

4. To nourish the hair follicles

The correct answer is: To elevate hair and create goosebumps

The function of the arrector pili muscle is to elevate hair and create goosebumps. This small, smooth muscle is attached to the base of hair follicles and contracts in response to cold temperatures or emotional stimuli such as fear. When the muscle contracts, the hair shaft is pulled upright, which can cause the skin to form small bumps—commonly known as goosebumps. This physiological response serves evolutionary purposes, including making an animal appear larger to predators or enhancing insulation by trapping air and creating a layer of warmth. In humans, although we may not have a significant fur covering, the mechanism still works and is often noticeable when we experience certain stimuli. Other options, while related to hair and its characteristics, do not accurately describe the specific role of the arrector pili muscle. The muscle does not involve itself in determining hair color, providing nourishment, or directly supporting growth; those functions are managed by different biological mechanisms such as melanocytes for color and the overall health of the hair follicle for growth.