Explain why you lose both motor and sensory function of a part of your body when a spinal nerve is numbed with anesthetic agents.

Video transcript

Hi, everybody. Let's take a look at our next question. Choose the best statement or statements that accurately describes how anesthetic agents work on both sensory and motor nerves. A anesthetic agents work by severing the nerves that connect to the CNS B. Anesthetic agents inhibit the transmission of signals between the nerves and the brain. C. Both statements are accurate or d both statements are incorrect. Well, hopefully it's pretty easy to rule out choice A that they work by severing the nerves that would cause permanent or semi permanent damage. You wouldn't be able to just let anesthesia wear off, definitely wouldn't be something you would want. So let's focus on choice B that they inhibit the transmission of signals. This is indeed the way that anesthetic agents work. So we can rule out both statements are accurate and d both statements are incorrect. So a local anesthetic, we have local anesthetic agents and local anesthetic agents work by inhibiting the function of sodium channels in the cell membranes of nerve cells near the injection site. That's why it's local. And when they inhibit that sodium channel function, those nerve cells cannot carry the signal. The signal can't be propagated from one cell to another. So those pain messages can't be carried from the area that is being anesthetized to the brain. And of course, general anesthesia causes a loss of awareness for the patient, but their vital functions continue to function. So that results in a loss of sensory information about pain throughout the body, not just in one area. And again, these work by choice B inhibiting the transmission of signals between the nerves and the brain. See you in the next video.