The spinal cord is a part of the brain that sends information to the rest of the body. Also known as the spinal column, the spinal cord contains a large about of nerve cells and fibers. It is so fragile that there are three protective layers over the spinal cord. These protective layers are called meninges and include the lura mater, the arachnoid and the pia mater. The lura mater is found on the outside and is a tough protective layer. The pia mater is found on the inside and is the tissue that carries blood to the spinal cord. In between the lura mater and the pia mater is the arachnoid, this layer is compared to a spider web because it is so delicate. The pia mater is also known as the subarachnoid space around the spinal cord. This area contains cerebrospinal fluid. Doctors use the cerebrospinal fluid from the subarachnoid space for spinal taps to diagnose disorders of the brain. Inside the spinal cord, there is both white matter and grey matter. The grey matter holds the cell bodies of motor nerves and sensory fibers. The white matter holds nerve fibers going to and from the brain. The two columns in the spinal cord, posterior and lateral, are also important. The posterior column holds ascending nerve fibers the carry sensory impulses to the brain and both columns carry motor impulses from the brain to the spinal cord.

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