Goosebumps are a normal physiological function of the human body.
The epidermis is one of the important ways for the human body to dissipate heat. Heat dissipation controlled by pores is one of the ways of epidermal heat dissipation. When there is excess heat in the human body, the pores open and the heat is dissipated. When a person feels cold, it means that there is not enough heat in the body, or the heat dissipates too quickly, so the pores close to preserve body heat. The goosebumps we see are bulges caused by contraction of the arrector pili muscles.
This is because in addition to protecting our internal organs and excreting sweat, human skin can also regulate and maintain body temperature. When the skin is stimulated by cold, the sensory cells under the skin will immediately notify the brain, making the person feel cold. At the same time, the arrector pili muscles under the hairs will contract, making the hairs stand up. At this time, the surface of the skin becomes very tight, forming a protective wall to prevent the loss of body heat. When the arrector pili muscle contracts, it pulls the hair root, causing the hair to stand upright. When you want to straighten the hairs, you will pull up a piece of skin, forming small bumps that look like chicken skin with the hair removed, so they are called goosebumps. Goosebumps are a manifestation of the skin's self-defense function. It reminds people to "keep warm and be careful of getting cold." At this time, you should take measures to keep warm immediately to avoid catching a cold.