Neuromuscular Junction Flashcards
what are the five steps of synaptic transmission
5 possible targets of drugs and toxins
synthesis of neurotransmitters
storage of neurotransmitters in vesicles
exocytosis of transmitters
transmitters bind to post-synaptic receptors
transmitters dissociate
why are neurotransmitters stored in vesicles in the pre-synaptic neuron
prevent them from metabolism
package them together
what causes exocytosis of transmitters from pre-synaptic neurons
opening of voltage-gated calcium channel
what do transmitters do when they bind post-synaptic receptors?
cause conformational changes
change the activity of the receptor
what facilitates transmitter dissociation
what happens to them afterwards
enzymes
broken down into components, some recycled
what is an agonist
substances which bind specific receptors and elicit a biological response
agonists:
affinity?
efficacy?
Reversible?
posses affinity and efficacy
always reversible
what is an antagonist
substances which bind specific receptors and do not activate them
antagonists:
affinity?
efficacy?
Reversible?
posses affinity but lack efficacy
not always reversible
which has higher binding affinity, antagonists or agonists?
how can the other still bind first
antagonists tend to have a higher affinity
agonists can bind first if at a higher concentration
what are the two moieties of acetylcholine
acetyl moiety
choline moiety
which subunit of nicotinic receptors does ACh bind
transmitter gated Na+ ion channels
alpha
how can a Na+ ion channel be isolated from a post-synaptic neuron
patch-clamp
how can mepps and epps be measured
microelectrodes
explain mepps
miniature end plate potentials
spontaneous depolarisations
depolarisation caused by a single vesicle
not sufficient to cause an AP
