What is the Central Nervous System (CNS)?

The Central Nervous System is composed of the brain and spinal cord. The brain has 12 Cranial Nerves. The spinal cord, which originates immediately below the brain stem, extends all the way down to the first lumbar vertebra (L1). Beyond L1 the spinal cord is known as the Cauda Equina. The spinal cord provides a means of dual communication between touch, taste, feel, sight, call-to-action and any other message that needs to be sent to the brain, which in turn will relay the action message to the peripheral nerves. A continuous 2-way traffic flow.

BRAIN12 Cranial Nerves
Motor:5 nerves
Sensory:3 Nerves
Motor/Sensory:4 Nerves


SPINAL CORD31 Pairs – Spinal Nerves
Cervical:8 pair
Thoracic:12 pair
Lumbar5 pair
Sacral5 pair
Coccyx1 pair

Just below the last Thoracic (T12) and first Lumbar (L1) vertebra the spinal cord ends. From this point the spinal nerves, resembling a horse`s tail, become known as the Cauda Equina extending down to the coccyx. These nerves are protected by being suspended in spinal fluid.