What is the Function of the Spinal Cord? from Schmeg.com

   

The spinal cord is the made up of over one million neurons and acts as the information superhighway for the body, carrying electrical signals from all parts of the body to the brain and back again. In an adult human the spinal cord is approximately 44cm long. It is normally protected by the vertebrae - a series of ring like bones. Due to the nature of these bones they can be crushed, severely damaging the delicate cord beneath.

All the messages needed to control movement in the body travel down the spinal cord from the brain to the muscles. Everything that is sensed - pressure, temperature, pain - is relayed to the appropriate area of the brain to be dealt with in the correct manner. A special fatty coating called myelin surrounds many of the neurons in the spinal cord, drastically speeding up the relay of signals. In a healthy person a nerve impulse travels at approximately 200 meters per second.

Damaged neurons are unable to relay the electrical impulses needed to carry the important messages around the body. The messages from the brain to initiate movement can no longer get to the parts of the body affected by injury, and paralysis occurs. The sensory messages from those areas are unable to reach the brain and so the injured person will loose all sensations below the level of injury.

It is not just the feeling and movement that is affected by spinal cord injury though, there are many other effects associated including loss of bladder and bowel control, loss of sexual function and the inability to control body temperature. The affect on the control of blood pressure in the body is so severe that in many cases it can lead to the death of the sufferer. Even the emotions we feel are affected by damage to the spinal cord.

The degree of paralysis depends on the level of the injury. The higher up the spine the injury occurs the greater the impact it has. People who have suffered damage to the neck or shoulder region of the spinal cord will not only lose feeling and movement in both arms and legs, but may be unable to breathe without a ventilator, as the messages are unable to reach the diaphragm. This is known as tetraplegia or quadriplegia. Lower level injuries, known as paraplegia, result in the loss of control and feeling in the legs. The spinal cord does not need to be severed for paralysis to occur, in fact in the majority of cases the spinal cord remains intact but damaged.

Unlike other areas of the body, the neurons in the spinal cord are incapable of regeneration, meaning that damage to the spinal cord is permanent.

See also: Back Pain and Rib Cage Pain