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The nervous system – WJECThe human nervous system

Our nervous system allows us to detect and react to changes in the environment. Sense organs, like the eyes, detect changes and our central nervous system co-ordinates a response.

Part of Biology (Single Science)Variation, homeostasis and micro-organisms

The human nervous system

The human nervous system consists of:

  • the central nervous system (CNS) – the brain and spinal cord
  • the peripheral nervous system – nerve cells that carry information to or from the CNS
Diagram of the human central nervous system with the brain and spinal cord labelled

Information is brought to the central nervous system and taken away by nerves which are bundles of neurones. Neurones are long cells which carry electrical signals along their length. Where two neurones meet there is a tiny gap called a . The signal passes chemically across the synapse to the next neurone where the electrical impulse continues.

This diagram summarises how information flows from receptors to in the nervous system.

Diagram summarising how information flows from receptors to effectors in the nervous system.