Synapse Questions

Question 1

Explain how the release of acetylcholine reduces the membrane potential of the postsynaptic membrane

Answer 1

Depolarise
Because sodium channels open
When Acetylcholine binds to receptor

Question 2

What happens to sodium ions immediately after action potential passes along the neurone

Answer 2

Sodium ions move out by active transport

Question 3

Explain how local anaesthetic stops the patient feeling pain

Answer 3

Blocks channel
Sodium ions can’t enter
Prevents impulses passing from receptors

Question 4

Why would this response be regarded as controlled by a reflex arc

Answer 4

Receptor detects stimulus

Impulse to muscle

Reflex is automatic

Question 5

Name the type of neurone that stimulates muscles

Answer 5

Motor

Question 6

What type of tissues act as an effector

Answer 6

Glands
Or
Muscle tissue

Question 7

How are hormones and neurotransmitters different

Answer 7

Hormones reach all cells via the blood

Neurotransmitters secreted directly onto target cell

Question 8

Explain importance of reflex actions

Answer 8

Automatic
Escape from predators
Prevents injury

Question 9

Describe how info passes from one neurone to the next across a cholinergic synapse

Answer 9

Calcium ions enter axon
Vesicles fuse with membrane
Acetylcholine released
Diffuses across synapse
Binds with receptors
Sodium enter neurone
Membrane depolarised
Action potential produced if above threshold

Question 10

Give differences between a cholinergic synapse and a neuromuscular junction

Answer 10

Neurone to neurone vs neurone to muscle

No summation in muscle

Muscle response always excitatory

Question 11

Explain what causes transmission at a synapse to occur in only one direction

Answer 11

Neurotransmitter only in presynaptic neurone