15.6 Transmission Across A Synapse

Question 1

Cholinergic synapse definition

Answer 1

Synapse in which the neurotransmitter is acteylcholine

Question 2

Acetylcholine is made up of what?

Answer 2

Acetyl (ethanoic acid)

Choline

Question 3

Where do cholinergic synapses occur?

Answer 3

Between neurones and muscles

Question 4

Mechanism of transmission across a cholinergic synapse

Answer 4

• Ca2+ channels open in presynaptic neurone
• Ca2+ enters synaptic knob by facilitated diffusion
• synaptic vesicles fuse with presynaptic membrane
• releases acetylcholine into synaptic cleft
• acetylcholine binds to Na+ channels on post synaptic neurone
• Opens Na+ channels
• Na+ enters postsynaptic neurone
• new action potential in postsynaptic neurone
• acetylcholinesterase hydrolysis acetylcholine into acetyl and choline which diffuses back into presynaptic cleft
• ATP recombined acetylcholine
• Na+ channels close