Goose bumps are created when tiny muscles at the base of each hair, known as arrector pili muscles, contract and pull the hair erect. The reflex is started by the sympathetic nervous system, which is responsible for many fight-or-flight responses.As you may have noticed,
goosebumps tend to form when you're cold. They also form when you experience a strong emotional feeling, such as extreme fear, sadness, joy, and sexual arousal.
Goosebumps may also occur during times of physical exertion, even for small activities, like when you're having a bowel movement.
