One in which neurotransmitter is a chemical called acetylcholine
1 of 17
What is acetylcholine made up of?
acetyl (ethanoic acid) and choline
2 of 17
In what types of organisms are cholinergic synapses generally found?
In vertebrates
3 of 17
What causes Ca2+ ion protein channels on the presynatic membrane to open?
The arrival of an action potential at the end of the presynaptic neurone
4 of 17
Where do the Ca2+ ions diffuse into by facillitated diffusion?
Into the presynaptic neurone (synaptic knob)
5 of 17
What does the influx of Ca2+ ions cause?
The synaptic vesicles in the presynaptic neurone to fuse with the presynaptic membrane, releasing acetylcholine into the synaptic cleft
6 of 17
Why do acetylcholine molecules diffuse across the synaptic cleft very quickly?
There is a short diffusion pathway
7 of 17
What happens to the acetylcholine molecules then?
They bind to receptor sites on the sodium ion protein channels on the postsynaptic membranewhich opens them
8 of 17
In which direction is there an influx of Na+ ions?
Into the postsyanptic neurone
9 of 17
What does this influx of Na+ ions cause?
They generate a new action potential in the postsynaptic neurone
10 of 17
What does acetylcholinesterase do?
It hydrolyses acetylcholine into ethanoic acid and choline
11 of 17
What happens to the ethanoic acid and choline?
They diffues back across the synaptic cleft into the presynaptic neurone
12 of 17
What does the rapid breakdown of acetylcholine prevent?
It prevents new action potentials to be generated continuously so discrete transfers of information can be made
13 of 17
What is ATP released from mitochondria used for?
To recombine ethanoic acid and choline to form acetylcholine to be stored in synaptic vesicles for further use
14 of 17
What closes in the absence of acetylcholine?
Sodium ion protein channels
15 of 17
How may a drug stimulate the nervous system?
By mimicking a neurotransmitter, stimulating the release of more neurotransmitters or inhibiting the enzyme that breaks down the neurotransmitter (e.g. inhibiting acetylcholinesterase)
16 of 17
How may a drug inhibit the nervous system?
By inhibiting the release of a neurotransmitter or blocking receptor sites on sodium/potassium ion channels on the postsynaptic neurone
17 of 17
Other cards in this set
Card 2
Front
What is acetylcholine made up of?
Back
acetyl (ethanoic acid) and choline
Card 3
Front
In what types of organisms are cholinergic synapses generally found?
Back
Card 4
Front
What causes Ca2+ ion protein channels on the presynatic membrane to open?
Back
Card 5
Front
Where do the Ca2+ ions diffuse into by facillitated diffusion?
Comments
No comments have yet been made