QuestionSBA
QuestionChoice
This is incorrect as depolarisation of the pre-synaptic neurone would cause voltage-gated Ca<sup>2+</sup> ions to open.
10005190
e
Depolarisation of the pre-synaptic neurone causes voltage-gated Mg<sup>2+</sup> channels to open
QuestionChoice
This process is describing the role of Ca<sup>2+</sup> in excitation-contraction coupling. The influx of Ca<sup>2+<sup/> leads to a conformational change of synaptotagmin (a protein) which causes ACh vesicles to fuse with the presynaptic membrane, resulting in exocytosis.
10005186
a
Ca<sup>2+</sup> influx in the pre-synaptic neurone triggers acetylcholine (ACh) release into the synapse
QuestionChoice
The opposite occurs – the EPP decreases further away from the end-plate as there is a lack of nicotinic acetylcholine receptors away from the synapse.
10005189
d
The end-plate potential (EPP) increases further away from the motor end-plate
QuestionChoice
ACh is hydrolysed by acetylcholinesterase to acetyl and choline.
10005188
c
Acetylcholine (ACh) is broken down by acetylcholinase within the synaptic cleft
QuestionChoice
This is incorrect. Little K+ efflux occurs here as the resting membrane potential of the muscle fibre is very close to the K<sup>+</sup> equilibrium constant (E<sup>k</sup>).
10005187
b
Many K<sup>+</sup> ions leave the muscle cell membrane after the binding of acetylcholine (ACh)
Concept
Chapter
2693
3820
Neuromuscular junction
Topic
152
Neuroscience
13584
Which of the following occurs at the neuromuscular junction?
a