NERVOUS SYSTEM

Question 1

what are reflexes?

Answer 1

the fast automatic responses that respond to the stimuli without a person consciously doing it

Question 2

what are some examples of reflexes avoiding injury?

Answer 2

• if you touch something hot, your body will automatically pull your hand away from it
• if a bright light is shined in your eye, your pupil will automatically shrink allowing less light in
• if you get a shock, your body automatically releases hormones called adrenaline

Question 3

what are effectors?

Answer 3

these are muscles or glands that react to nervous impulses

Question 4

what is a synapse?

Answer 4

synapses are the connection between two neurons

Question 5

what are receptors?

Answer 5

cells that detect stimuli

such as taste receptors in the tongue

sound receptors in your ear

Question 6

describe the reflex arc

5 marks

Answer 6

when a stimuli is detected, impulses are sent along the sensory neurone to the relay neurone

when impulses reach a synapse between the sensory and relay neurone, they trigger chemicals to be released causing impulses to be sent along the relay neurone

when the impulses reach a synapse between the relay and motor neurone, the same thing happens.

finally the impulses travel along the motor neurone to the effector