Summary
Summary Alevel Biology AQA synaptic transmission notes
- Course
- Institution
These are some summary notes for synaptic transmission, information is simple and easy to remember and very condensed.
[Show more]
Seller
Followkatieguntrip
Content preview
3.6.2 Synaptic transmissionCholinergic synapses
Cholinergic synapses use the neurotransmitter acetylcholine
Unidirectionally
Synapses can only transport information in one direction across a synapse from the presynaptic
neurone to the post synaptic neurone.
The receptors are only on the postsynaptic membrane
Summation
The process by which the excitatory and inhibitory signals together are able to generate an action
potential or not
Temporal summation
A single presynaptic neurone releases neurotransmitters many times over a short period which can
cause concentration of neurotransmitter to exceed the threshold value of the postsynaptic neurone a
new action potential is then triggered.
Large amount of acetylcholine is released into synaptic cleft
Large number of gated ion channels open
Sufficient number of sodium ions pass through membrane
Spatial summation
When multiple different presynaptic neurones release enough neurotransmitters at once to exceed
threshold value and a new action potential is triggered in posy synaptic neurone
Benefits of summation:
Allows effect of stimulus to be magnified
Combination of different stimuli can trigger a response
Avoids nervous system from being overwhelmed by impulses
Transmission across a cholinergic synapse:
1. Arrival of AP, depolarisation of presynaptic membrane, voltage gated sodium ion channels
open
2. Calcium ions diffuse down electrochemical gradient from tissue fluid around synapse (high
concentration) to cytoplasm of presynaptic neurone (low concentration)
3. Stimulating acetylcholine vesicles to fuse with presynaptic membrane, releasing
acetylcholine in the synaptic cleft
4. Acetylcholine diffuses over synaptic cleft and temporarily binds to ligand-gated sodium ion
channels (receptor proteins) in postsynaptic membrane
5. Receptor proteins open, allowing sodium ions to diffuse down electrochemical gradient into
cytoplasm of postsynaptic neurone
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller katieguntrip. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.86. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67474 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now