Relate the structure of the spinal cord to its function. Include all levels of the cord.
The spinal nerve cord is a long, tubular bundle of nervous tissue and other cells extending from the brain. It is located in the vertebral canal of the backbone. Its function is the transmission of nerve impulses between the brain and the other nerves in the body--peripheral nerves. It is also in control of many reflex actions. It is a pathway for motor information from brain to motor nerves, it allows the transmission of sensory information from the various receptors towards the brain and is a center for conducting reflexes. Three layers of tissue called meninges protect the spinal cord and surround the canal. The dura mater on the outside forms a protective layer. Between this and the surrounding vertebrae, is the epidural space, filled with adipose tissue and blood vessels. The arachnoid mater is the center layer and the subarachnoid space below is where we find the cerebrospinal fluid. The innermost layer is the pia mater and it serves a protective function. Connective tissue in the dura mater stabilize the cord. The outside part of the cord in cross section is made of white matter with sensory and motor neurons. Inside of this is the gray, butterfly shaped central region consisting of nerve bodies. This surrounds the central canal and contains cerebrospinal fluid.