THE SPINAL CORD.

       The spinal cord consist of thousand of neurons clustered to form a cylindrical nervous tissue. It runs down the length of the neural canal formed by the stacking of the vertebrae, and hence occupies a dorsal position in the animals body.

     The spinal cord is enveloped within three membranes:

• The Meninges; which support and protects it. 
• The Spinal Canal; a narrow canal which runs down the centre of the cord. 
• The cerebrospinal fluid.

      A transverse section of the spinal cord shows a greyish central region, the grery matter, surrounded by a lighter region, the white matter.

     The grey matter is composed of practically all the cell body of the neurones in the spinal cord. Since the cell body are dense and granular, they give this region it's typically greyish appearance.
    The white matter consists of the nerve fibres of these cell bodies. Some of these fibres run along the spinal cord to the brain, connecting both. Others form the spinal nerves.
                         Functions of the spinal cord. 
The functions of the spinal cord includes;
• Co-ordinating simple reflex actions like the knee jerk and automatic reflexes such as               sweating.
• Acting as a pathway between the spinal nerves and the brain.