The nervous system coordinates the actions of complex organisms via the transmission of electrochemical signals:
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These signals are transmitted by a specialised network of cells called neurons.
The nervous system can be divided into two main parts:
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CNS (Central nervous system): Made up of the brain and spinal cord.
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PNS (Peripheral nervous system): Made of peripheral nerves which link the CNS to the body’s receptors and effectors.
Main Components of the Human Nervous System
CNS versus PNS:
The central nervous system integrates information received from peripheral nerves and coordinates bodily responses:
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The majority of this activity occurs in the brain, but certain responses can be mediated by the spinal cord (reflex actions).
The peripheral nervous system sends information to the CNS via sensory neurons and activates effectors via motor neurons:
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The peripheral nerves for a particular region of the body feed into the spinal cord at a particular site (anatomical dermatome).