Lesson: Chapter 6 — Human body processes

6.5. Co-ordination and the nervous system 3 of 5

The central nervous system

The nervous system has two parts: the central nervous system (brain and spinal cord) and the peripheral nervous system (the nerves).

Part	Made up of
Central nervous system	The brain and the spinal cord
Peripheral nervous system	12 pairs of cranial nerves from the brain, and 31 pairs of spinal nerves from the spinal cord

How the brain and spinal cord are protected

Bone

The skull encloses the brain and the backbone the spinal cord.

Meninges

Three membranes wrap the brain and spinal cord.

Cerebrospinal fluid

Fills the spaces between the meninges and inside the brain.

What the cerebrospinal fluid does

• Cushions the brain against knocks.
• Brings food and oxygen to the nerve cells.
• Carries their waste away.