What is an arrector pili muscle attached to?

The arrector pili muscle is a small, smooth muscle attached to the hair follicle. When this muscle contracts, it causes the hair to stand upright, a phenomenon commonly known as “goosebumps.” This reaction can be triggered by various stimuli, such as cold temperatures or emotional responses like fear or excitement. The contraction of the arrector pili muscles plays a role in thermoregulation by creating an insulating layer of air over the skin when the hair stands on end. Structurally, the arrector pili muscle is unique in that it originates at the base of the hair follicle and extends to the dermis, showcasing its specific connection to the hair structure rather than to glands or the skin surface directly.