List, in sequence, the five steps involved in a neural reflex.

Question

Accepted Answer

Hi, everyone. Welcome back. Let's take a look at our next problem. The following is the list of the events involved to produce neural reflexes through nerve impulses. We have a list of five events with Roman numerals. One sensory neuron activation, two motor neuron activation, three information processing in the CNS four receptor activation and five per peripheral effector response. Then our question asks, which of the following gives the correct sequence of these events to produce reflexes? A 12345 B 41253, C 31254 or D 41325. So let's think about the basic organization of a, how a reflex happens. You have a stimulus that produces a response. So if we're picking out events, we first want to think about the events that have to do with perception of a or reception of a stimulus. Well, two of our events have to do with the stimulus. One is sensory neuron activation. So I'm gonna write stimulus next to that and the other is receptor activation. And this one can be a little bit tricky because we may want to jump at that statement. One sensory neuron activation because we think oh sensory neuron picking up impulses. But we have to think about the fact that the stimulus is first perceived by the receptors and then the sensory neuron is activated if that stimulus is enough to generate an action potential in the sensory neuron. So little bit of a tricky distinction there and remember that receptors might be a cell, a receptor cell that's monitored by a sensory neuron. Or it could be uh the sen the processes of the sensory neuron itself. So it may all be happening within the same cell, but it's two distinct events. So our first event will be statement four receptor activation. So let's look for answer choices that have choice four as the first one. Well, statement or choice A has number one first. So we've talked about why that's not the case. But choices B and D start with statement four. Choice C, it starts with statement three. So we're going to cross that right off. So we have one and two, we know that we're going to end with the response. So let's jump to that. So the response would be some sort of motor activation. And so we would be looking at the actual muscle doing something well, that technical term would be an effector. We see that in statement five, this one's a little tricky because we might be looking for muscle or we'll be thinking about motor. We see that in statement two, we have motor neuron activation. So again, we might be tempted to jump on motor neuron activation because we're thinking about a motor response. But the actual thing, be it a muscle or a gland that response to stimulation by the motor neuron is a peripheral effector. So the actual muscle movement is the peripheral effector response. So this should be last. There's a bit of an odd way of going about it. But sometimes when we think about reflexes, the most sort of pertinent parts, the parts that we think of the most are that stimulus response, which is why I'm kind of thinking through it this way, which is how I'd approach it on a test. So we want to look for our answer choice that has choice five at the end out of B and D. So B has choice three. So we'll cross that off but D has choice five. So by process of elimination, choice D must be correct. Let's just confirm that. So we have our peripheral effector response happening last. We were debating about whether it would be motor neuron activation. So that's a pretty obvious choice for event number four. And indeed, that is the motor neuron is activated by an action potential being generated. And that sends the message or the signal to the peripheral effector to make the reflex happen, the ref the reflex action happen. So now we've got right in the middle information processing and CNS And yes, that would make sense that that's in the middle. Where does our sensory information go to the central, central nervous system which then sends out the message to the motor neuron? So indeed, when we look at choice or answer choice, D we have number of statement four receptor activation, then statement one sensory neuron activation, then statement number three information processing in the CNS followed by number two motor neuron activation finishing with statement five peripheral effector response. So once again, that is choice D as the correct sequence of events. See you in the next video.

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List, in sequence, the five steps involved in a neural reflex.

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