Flashcards
Synaptic transmission
Cards in this deck (9)
- 1What is the neuromuscular junctionHow a signal is passed from nerve to skeletal muscle fibre
- 2How is calcium involved in neurotransmitter release?. Action potential depolarizes membrane causing calcium channels to open and calcium influx (ec Ca2+ = 1mM ic Ca2+ = 10uM)
. [Ca2+] increases a lot this promotes exocytosisand so release of the neurotransmitter - 3How is Ca2+ influx related to a.pmore ap's more Ca2+ influx more transmitter released
- 4Describe the properties of Ca2+ channelsActivate more slowly than Na+ channels
Acivate and inactivate
Ca2+ inactivation is Ca2+ dependent (Ba2+) - 5Describe the structure of the post-synaptic muscle membraneHas junctional folds with acetylcholine receptors at the top and acetylcholine esterase embedded on the membrane
- 6Describe the process of transmitter releaseCa2+ entry
Binds to synaptotagmin
Vesicle brought close to membrane
Snare complex makes fusion pore
Transmitter released through pore - 7How is skeletal muscle depolarised?Transmitter bunds to nictotinic AChR which is a cation channel
2 ACh cause them to open
Causes depolarisation of end-plate potential
(dependent on ec CA2+ concentration)
Local charge causes muscle action potential which causes contraction - 8How does curare work?Curare is a paralytic
d-tubocurarine is a competitive blocker to ACh
(blocks neuromuscuar transmission) - 9How does succinylcholine work?It is a depolarizing block it stimulates nAChR but can't be degraded
- maintained depolarization fails to cause local currents so no depolarisation
STEADY-STATE INACTIVATION of Na+ channels
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- Physiology Flashcards on Synaptic transmission, created by Charlotte Pedley on 11/05/2018.
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- Charlotte Pedley
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