35. Neuromuscular junction

  1. When action potential arrives at the presynaptic neuron terminal, voltage-dependent calcium channels open and calcium ions flow from the extracellular fluid into the neuron?
  2. Influx of calcium into the neuron triggers the fusion of acetylcholine  vesicles with the membrane and the release of ACh into the synaptic cleft?
  3. Nicotinic and muscarinic ACh receptors (AChRs) are ligand-gated ion channels?
  4. The binding of ACh to nicotinic AChR in the postsynaptic muscle membrane opens a calcium channel within the receptor allowing calcium influx and depolarization of the muscle membrane?
  5. Two ACh molecules must bind with each AChR to open its channel?
  6. Choline acetyltransferase in the synaptic cleft decomposes ACh into choline and acetic acid?

  1. T
  2. T
  3. F
  4. F
  5. T
  6. F