What Are the Functions of the Nerve Endings in the Skin?

Perceiving the World

• The principal function of the nerve endings in the skin is to communicate information about the outside world to the brain. Different types of nerve endings perceive different things like heat, cold, pain, pressure and contact. This information allows the brain to understand the environment and base decisions upon its qualities.

Hot and Cold

• As well as informing the conscious part of the brain about what is going on in the environment, the nerve endings also trigger many automatic responses. The body's reactions to hot and cold are key examples of this. If the nerves in the skin inform the brain that the body is too hot, then other nerves in the skin trigger sweat glands to produce sweat to carry away the heat as it evaporates. Conversely, nerves reacting to low temperatures will cause the constriction of blood vessels near the skin. This keeps the blood away from the surface and so retains the body's heat.

Pain Reaction

• Not all signals from the skin are sent to the brain for processing before they precipitate an action. Extreme, sudden sensations of pain in the skin will trigger the muscles to immediately withdraw the painful part of the body from the pain source. This is know as a reflex and is triggered by a reflex arc. This is when a signal from a nerve in the skin causes a reaction in the spinal cord before the signal even reaches the brain. This reaction causes an impulse to be fired along a nerve to the appropriate muscle group, causing a fast movement of the afflicted part of the body.

Blushing

• Another reason that nerve cells allow or constrict the flow of blood to the surface of the skin is to allow blushing. Blushing occurs in response to emotional states such as shame or embarrassment. These emotions trigger nerve endings in the skin to open the blood vessels and cause reddening of the skin. The exact function of blushing is widely debated, though one argument is that, as blushing is involuntary, it indicates genuine remorse in the person who has committed a wrong deed. This encourages others to forgive the wrongdoer.