The peripheral nervous system consists of all the nervous tissue outside of the central nervous system. Peripheral nerves innervate the muscles and organs. Part of the peripheral nervous system called the autonomic nervous system is responsible for controlling body processes like breathing, digestion, sweating, and shivering. The autonomic nervous system has two parts: the sympathetic and the parasympathetic nervous systems. The sympathetic nervous system prepares the body for sudden stress, as when you see something catch fire or witness violence. As something frightening happens, the sympathetic nervous system makes the heart beat faster which sends blood more quickly to body parts that might need it. The sympathetic nervous system also causes adrenal glands located at the top of the kidneys to release adrenaline. Adrenaline is a hormone that gives extra power to the body for quick action otherwise known as the body’s “fight or flight” response. The parasympathetic nervous system is opposite in function: It prepares the body for rest and also helps the digestive tract move along so our bodies can efficiently take in nutrients from the food we eat.