piloerection

**piloerection**

Piloerection, commonly known as “goosebumps,” refers to the involuntary erection of hair follicles caused by tiny muscles called arrector pili. This physiological response is usually triggered by cold temperatures, emotional reactions such as fear or excitement, or certain medical conditions. In humans, piloerection is a vestigial reflex inherited from our animal ancestors, where it helped to trap heat or make the animal appear larger to predators. This tag covers content related to the biology, causes, and significance of piloerection in humans and other animals.