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Science

The nervous system

Central nervous system

An animal's response to a stimulus is coordinated by its central nervous system (CNS). The CNS consists of the brain and the spinal cord. It gathers information about, and responds to, changes in the environment.

Receptors detect a stimulus and send impulses along sensory neuronssensory: Sensory neurones carry messages from sense organs into the CNS to the CNS. The CNS coordinates the information and sends impulses along motor neurons to the effectors, which bring about a response. The sequence is as follows:

  1. Stimulus
  2. Receptor
  3. Sensory neuron
  4. Central nervous system
  5. Motor neuron
  6. Effector
  7. Response

The peripheral nervous system

The peripheral nervous system (PNS) consists of motor and sensory neurons that carry impulses from the receptors to the CNS, as well as impulses from the CNS to the effectors.

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