Biology 2-nervous system

Biology 2-nervous system

1. The nervous system is made up of two parts-the central nervous system and the peripheral nervous system

   • The brain and the spinal cord form the CNS which interprets and coordinates the information
   • The PNS has nerves and receptors
     • Receptors are cells or modified nerve endings which can respond to a stimulus
   • The receptors detect stimuli and send electrical impulses to the CNS

2. There are 5 sense organs-the eyes, skin, ears, nose and tongue

   • The ear detects sounds and converts them to electrical signals
   • Light enters the eye through a pupil
   • The nose and tongue both have sensory cells to detect dissolved substances

3. The nervous system contains many nerve cells called neurones

4. Reflex actions is a rapid automatic response which protect the body e.g. makes you take your hand away from a hot object

5. Synapses are junctions in-between neurones. The synapses pass information between neurones.

6. Dendrites are at the ends of the nerve cell bodies and they interconnect with neurones to pass the nerve impulses from one neurone to another