What is spinal cord and their function?

 

THE SPINAL CORD

The spinal cord is a thin, long, circular bundle of nervous tissue that support cells that spread from the medulla oblongata in the brain to the lumbar region of the vertebral column. The spinal cord is the part of central nervous system (CNS).

 Function of spinal cord

The spinal cord have two important functions in an animal. It is connect the brain with other of the body, and it have the function of spinal reflex actions. A reflex is a predictable, involuntary involve to a stimulus. Thus, both voluntary and involuntary limb movements, in addition to certain organ functions, depend on this  connection of brain with body.
The spinal cord is the part of the central nervous system that start near the brain or go into the tail. A neural canal is present that contains cerebrospinal fluid.

The gray matter contain cell bodies and dendrites, and is concerned mainly with reflex connections at various levels of the spinal cord. Extending from the spinal cord are the ventral and dorsal roots of the spinal nerves. These roots contain the main motor and sensory fibers respectively, that contribute to the major spinal nerves.

The white matter of the spinal cord consit of the whitish myelin that covers the axons.
Three layers of protective membranes called meninges surround the spinal cord. They are continuous with similar layers and cover the brain. The outer layer, the dura mater, is a tough, fibrous membrane. The middle layer, the arachnoid, is delicate that connects to the innermost layer, the pia mater. 

 The pia mater consist of small blood vessels that nourish the spinal cord.