Neuromuscular Junction — Nerve & Muscle Physiology

Neuromuscular Junction MCQs: practice questions

Sample Neuromuscular Junction multiple-choice questions from Nerve & Muscle Physiology.

1. At the motor end plate, acetylcholine binds primarily to:

   • A. Muscarinic receptors
   • B. NMDA receptors
   • C. GABAB receptors
   • D. D2 receptors
   • E. Nicotinic receptors

2. The neurotransmitter released by a somatic motor neuron at the neuromuscular junction is:

   • A. Acetylcholine
   • B. GABA
   • C. Dopamine
   • D. Glutamate
   • E. Norepinephrine

3. The nicotinic receptor at the motor end plate is a:

   • A. G protein-coupled receptor
   • B. Ligand-gated cation channel
   • C. Nuclear receptor
   • D. Voltage-gated K+ channel
   • E. ATPase

4. A neurotransmitter that opens Cl− channels in a postsynaptic neuron is most likely to produce:

   • A. Excitation
   • B. A muscle action potential directly
   • C. Inhibition
   • D. Na+ accumulation
   • E. Ca2+ release from the SR

5. A neurotransmitter that increases K+ conductance is generally:

   • A. Excitatory
   • B. Inhibitory
   • C. Always depolarizing
   • D. A hormone
   • E. An enzyme

6. A chemical synapse normally transmits information:

7. Acetylcholinesterase terminates acetylcholine action by:

8. Myasthenia gravis most directly involves antibodies against:

9. Why can excess acetylcholinesterase inhibition eventually cause weakness?

10. Acetylcholine is released from the motor nerve terminal when an action potential opens:

11. Lambert-Eaton syndrome primarily impairs:

12. Curare-like drugs cause skeletal muscle paralysis by blocking:

13. The synaptic delay at a chemical synapse is largely due to:

14. An excitatory postsynaptic potential generally moves the membrane:

15. Presynaptic inhibition commonly reduces neurotransmitter release by decreasing:

16. Which toxin blocks voltage-gated Na+ channels and therefore prevents both nerve conduction and transmitter release?

17. A small postsynaptic depolarization at one synapse is called a:

18. Which process recycles membrane after synaptic vesicle fusion?

19. Which event occurs last in normal neuromuscular transmission?

20. A depolarizing neuromuscular blocker initially causes:

21. A presynaptic action potential reaches a nerve terminal. What is the correct sequence?

22. Opening nicotinic receptors produces an end-plate potential primarily because of:

23. The immediate trigger for synaptic vesicle fusion is an increase in presynaptic:

24. Which finding favors Lambert-Eaton syndrome over myasthenia gravis?

25. Which mechanism allows a postsynaptic neuron to integrate many synaptic inputs?

26. The motor end plate differs from a typical neuronal postsynaptic membrane because it has a high density of:

27. A patient with myasthenia gravis receives a reversible acetylcholinesterase inhibitor. The expected effect is:

28. Botulinum toxin causes weakness primarily by preventing:

29. An inhibitory postsynaptic potential generally:

30. A drug that inhibits acetylcholinesterase would initially: