you the spinal cord is a very important part of our central nervous system the overall system that controls and coordinates the activities of our bodies our brain is surrounded by the skull while our spinal cord is surrounded by rings of bone called vertebrae and both are covered by a protective membrane together the vertebrae in membrane make up our spinal column or our backbones the backbone which protects our spinal cord starts at the base of our skull and ends just above our hips the spinal cord is about 18 inches long and extends from the base of the brain down the middle of the back to just below the last rib in the waist area the main job of the spinal cord is to be the communication system between the brain and the body by carrying messages that allow us to move and feel sensation our spinal nerve cells called neurons carry the messages to and from the spinal cord these messages leave the spinal cord through openings in the vertebrae spinal nerve roots branch off the spinal cord in pairs one going to each side of the body each nerve has a specific job for movement and feeling they tell the muscles in your arms and fingers legs toes chest and other parts of your body when and how to move when a spinal cord injury occurs sensation and movement may be interrupted resulting in a temporary or permanent loss of function and paralysis in general the higher on the spinal cord the injury occurs the greater loss of function the person may experience the vertebrae are grouped into sections according to their location for example the seven vertebrae in the neck called the cervical vertebrae the vertebrae are numbered top to bottom from the head to the tailbone the top vertebra is called c1 the next is c2 c3 and so on cervical spinal cord injuries usually cause loss of function in the arms and legs resulting in tetraplegia which is also called quadriplegia the next 12 vertebrae are called the thoracic vertebrae the first t1 is where the top rivet a ch's injuries in the thoracic region usually affect the trunk and legs and result in paraplegia the lumbar vertebrae are the five vertebrae in the lower back between the thoracic vertebrae where the ribs attach and the pelvis or hip bone the sacral vertebrae run from the pelvis to the end of the spinal column injuries to the five lumbar vertebrae l1 through l5 and similarly to the five sacral vertebrae s1 through s4 generally result in some loss of functioning in the hips and legs whether the cause of a spinal injury or illness is traumatic or non-traumatic the damage affects the nerve fibers passing through the injured area that can damage or weaken part or all of the corresponding muscles and nerves below the injury site doctors have already or will assign your loved one a level of injury that corresponds to the damage below the injury in Chapter five we'll explain more about these injury levels and how they can impact you or your loved one right now we'll move on to chapter three to inform you about some things that may occur soon after the immediate spinal cord injury or illness