Synapses and Reflexes

Question 1

What is a reflex?

Answer 1

-they are rapid, automatic responses to certain stimuli that don’t involve a conscious part of the brain
-e.g. if someone shines a bright light in your eyes the pupil will automatically get smaller so less light gets into it to reduce the chances of it getting damages

Question 2

what is a reflex arc?

Answer 2

the passage of information in a reflex (from receptor to effector)

Question 3

How does a reflex arc work?

Answer 3

1)the neurones in a reflex arc go through the spinal cod or through an unconscious part of the brain
2) when a stimulus is detected by receptors (e.g. a bee stings), impulses are sent along a sensory neurone to a relay neurone in the CNS
3)when the impulses reach a synapse between the sensory neurone and the relay neurone they trigger chemicals to be releases which cause impulses to be sent along the relay neurone
4)when the impulses reach a synapse between the rely neurone and motor neurone the same happens- chemicals are releases and cause impulses to be sent along the motor neurone
5)the impulses then travel along the motor neurone t the effector (which is usually a muscle)
6)the muscle then contracts and moves your hand away from the bee for example
*as reflexes happen without having to think about the response they happen faster than normal responses

Question 4

What is a synapse and what is its role?

Answer 4

-the connection between 2 neurones is called a synapse
-the nerve signal is transferred by chemicals which diffuse across the gap
-these chemicals then set of a new electrical signal in the next neurone

Question 5

What is a pneumonic to help remember the order of a reflex arc?

Answer 5

Some (stimuli)
Randy(receptors)
Sluts (sensory neurone)
Ride (relay neurone)
Mens (motor neurone)
Erections (effectors)
Regularly (response)