The Central Nervous System (CNS)

The CNS is made up of the brain and spinal cord only.

Receptors in a sense organ will detect a stimulus, they then sense electrical impulses along sensory neurones to the CNS.

The CNS will then send a message to and effector, it does this by sending an electrical signal along a motor neurone, the effector will then act accordingly.

The role of the CNS is to coordinate the response, to have a coordinated response, there will always need to be a stimulus, receptor and effector.

By using high speed electrical impulses the nervous system can have very rapid responses.

As quickly as the brain can be at deciding how to respond to stimuli, it at times is too slow, this is where the body will use and automatic reaction called a reflex.

	Created by lingox over 10 years ago

IGCSE Biology Paper 1B Note on The nervous system and stimuli, created by lingox on 07/05/2014.