Topic 2:Neurotransmission and speeds

Question 1

What is an effector?

Answer 1

• carries out an action

- include glands and muscles

Question 2

Motor neurones

Answer 2

• carry impulse to effector
• no dendron
• dendrites on cell body

Question 3

Relay neurones

Answer 3

• short neurones found on the spinal cord - link motor and sensory neurones
• no dendron
• dendrites on cell body

Question 4

Synapse

Answer 4

• contains a tiny gap
• when it reaches an axon terminal - neurotransmitter substance released into gap
• diffusion
• detected by the next neurone
• generates new impulse

Question 5

Synapses slow down neurotransmission but why are they useful

Answer 5

• only released from one axon terminal so it flows in one direction
• allow many fresh impulses to be generated - original impulse doesn’t need to be split or lose strength

Question 6

Explain the reflex arc

Answer 6

• reflex actions are automatic - extremely quick and protect the body
• bypasses the part of the brain so it is faster

sensory neurone - spinal cord - relay neurone - motor neurone - effector