Central Nervous System

The body’s processing core — the brain and the spinal cord. Abbreviated CNS.

Parts

• Brain — the control center: the cerebrum (thought, sensation, voluntary movement), the cerebellum (coordination and balance), and the brainstem (vital automatic functions).
• Spinal cord — the main communication cable between brain and body; it also runs some reflexes on its own.

Protection

Encased in bone (skull and vertebrae), wrapped in membranes (the meninges), and cushioned by cerebrospinal fluid.

What it does

Receives and integrates information, makes decisions, stores memory, and issues commands.

Key idea

The CNS is where information is actually processed; the rest of the nervous system mostly carries signals to and from it.