Nervous System
The brain, spinal cord and nerve network that command every voluntary and involuntary action.
The nervous system is the body's command-and-control network — the brain and spinal cord form the central hub, while a web of peripheral nerves relays sensation and motor commands throughout the body. It governs everything from conscious thought to the millisecond reflexes that keep you upright, and it is unusually responsive to sleep, stress and exercise.
Key organs & structures
How it connects
The hypothalamus links the nervous and hormonal systems directly.
Every voluntary muscle contraction begins as a nerve signal.
Chronic stress measurably slows digestion via the gut-brain axis.
Deep-dive guides in the nervous system
Conditions involving this system
Symptoms involving this system
Did you know?
- • Signals in some nerve fibres travel at speeds exceeding 100 metres per second.
- • The brain generates enough electrical activity to be measured from outside the skull, which is the basis of EEG.