A local anaesthetic blocks voltage-gated sodium channels in a sensory nerve. Which effect is expected?
Correct answer: B. Failure of action potential conduction along the nerve
- A. Faster release of acetylcholine at the synapse
- B. Failure of action potential conduction along the nerve
- C. Increased sensitivity of the sensory receptor
- D. Continuous contraction of the supplied muscle
Explanation
Sodium channel blockade prevents the depolarization needed to start and conduct an action potential, so pain signals cannot travel normally. The drug does not increase receptor sensitivity or directly cause continuous muscle contraction.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Nervous System and Special Senses
The nervous system covers neurons, neuroglia, nerve impulses, synapses, reflex arcs, and the organization of the central and peripheral nervous systems. It also explains the autonomic divisions and the receptors and pathways for vision, hearing, balance, taste and smell, distinguishing sensory reception from conscious perception.
Practise Nervous System and Special Senses
40 free Nervous System and Special Senses MCQs from Anatomy and Physiology for Nursing, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Anatomy and Physiology for Nursing questions like this
Anatomy and Physiology for Nursing is on 4 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Nervous System and Special Senses questions
Which cell forms myelin around axons in the peripheral nervous system?
Which change occurs when a neuron generates an action potential?
Which neurotransmitter is released by most postganglionic parasympathetic neurons at their target organs?
What is the main function of myelin in a nerve fibre?
At a chemical synapse, which event directly causes neurotransmitter release from the presynaptic terminal?
A student looks at a nearby book after first looking at a distant object. Which change helps the eye focus on the book?