The nervous system Flashcards
What is a stimulus?
A change in the environment which you may need to react to
What are the 5 sense organs?
1) eyes 2) ears3) nose 4) tongue
5) skin
What are receptors?
Groups of cells which are sensitive to a stimulus. They change stimulus energy into electrical impulses
What can a stimulus be?
1) light
2) sound
3) touch
4) pressure
5) pain
6) chemical
7) a change in position or temperature
What is the CNS and what does it involve?
The central nervous system. It only involves the brain ad spinal cord
What are neurones and what do they do?
They are nerve cells that transmit information as electrical impulses to and from the CNS
What are effectors?
Muscle or glands
What do sensory neurones do?
Carry signals as electrical impulses from the receptors in the sense organ to the CNS
What do relay neurones do?
Nerve cells that carry signals from sensory neurones to motor neurones
What are motor neurones?
The nerve cells that carry signals from the CNS to the effector
What to effectors do?
Muscles contract and gland secretes hormones
What do synapses do?
Connect neurones
What are reflexes and what do they do?
They are automatic responses that prevent injury
Where the reflex arc go?
Through the CNS
