Spinal Cord

The medulla spinalis extends from the membrane bone of the skull until it terminates near the second vertebra . The spinal cord is protected by three layers of meninges: the dura mater, the arachnoid mater, and the pia mater. The central nervous system (CNS) is made up of the brain and spinal cord. The area between the arachnoid space and therefore the meninx contains cerebral cerebrospinal fluid (CSF). The medulla spinalis is split into 31 segments that send nerve rootlets out into the body through intervertebral foramen. Each segment of the medulla spinalis is related to a pair of ganglia called dorsal root ganglia, which are situated just outside of the medulla spinalis and contain cell bodies of sensory neurons. These neurons travel into the medulla spinalis via the dorsal roots.