Your spinal cord is a soft, rope or cable -like structure that is made up of millions and millions of nerves. It starts at the base of your brain to the lower part of your back. Its purpose is to carry information between the brain and, by way of the peripheral nerves, to other parts of the body, such as the arms, legs, and all of the organs in the body. Some of the nerves in the spinal cord send messages telling a particular body part to move in a certain way. Other nerve fibers send messages about heat, cold, or pain. Some nerves tell your bladder or bowel to “hold on a little longer,” or “it’s OK to go now.” Still others control your body’s involuntary (autonomic) activities, such as your blood pressure, body temperature, and sweating. In addition, information from various parts of your body travels back to the brain by way of the spinal cord.