Cutis anserina, commonly referred to as goosebumps, is a temporary condition where the skin becomes rougher due to the contraction of small muscles, often triggered by cold, fear, or excitement. This process is initiated by a stimulus such as cold or fear, which activates a nerve from the autonomic nervous system. The nerve signals cause the arrectores pilorum muscles, responsible for raising the hair, to contract. As a result, the hair follicles are elevated above the skin surface, creating the small bumps we recognize as goosebumps.This phenomenon is also known as "goose flesh" or "goose pimples." In medical terminology, it is referred to as "cutis anserina," which again links back to the goose, with "cutis" meaning skin and "anser" meaning goose, translating to goose skin.Some biologists suggest that goosebumps evolved as part of the fight-or-flight response, which also includes increased heart rate and enhanced blood flow to the muscles for extra oxygen. In animals with fur, a similar reaction called bristling may have served to make them appear larger and more intimidating, as well as to keep them warmer by trapping air between the fur, thereby retaining body heat.
