 back to the reflex. All right, here we go, eliciting stimuli. So the stimulus elicits the response of, pew, out it comes, right? In reality, it's not one single stimulus, it's a class of stimuli, right? So there's a lot of ways to puff air into my eye. Just a paper here, I'm going to puff some air into my eye in one way. I blink, right? You could sit there with a turkey-based drink, and I would blink, right? It's all a class of stimuli, puff of air. It doesn't have to be the same kind of air. It doesn't have to be the same temperature air. It doesn't have to be the same color air. It doesn't have to be air. Just stuff blown into your eyes, right? And then you'll react to that. So it's a class of stimuli. So something blowing at you will then cause your eyes to blink, or getting dust and things like that. That is associated with a corresponding response. Now here's the thing. The way the reflex works is that you've got a stimulus and response. The response, in order for it to be a reflex, needs to not really be happening very often without the stimulus present. What a wishy-washy way to say that. Basically, the point is, is that these responses like blinking your eyes, all right? I can do that without the eliciting stimulus present, but it's often not going, more often than not, it's not going to be the case. I'm only going to blink my eyes when a couple of things happen, when I need to moisten my eyeballs, I guess, my brain detects that, or when there's a puff of air to it. So that's one of those important things about the reflex, is that those two things are tied together really, really closely. Of course, we can talk about all the sensory neurons and the motor neuron, afferent, afferent neurons, blah, blah, blah, blah, blah, all that fun stuff. So you get the sensory neuron, picks up the stimulus, and motor neuron, the stimulus goes, bounces around the body. Sometimes it just goes through an inner neuron before the signal gets to the brain. Sometimes it goes all the way up to the brain and back down. All depends on what type of reflex you're talking about beyond the scope of this course. Oh, I guess I have inner neuron on here. I should probably put that up there. So again, sensory neuron picks up the signal. So if I touch something hot, right, touch something hot with my fingers, a hot pad or something like that, and you zip my hand back. Well, the first thing that's going to happen with that particular case is that the signal is going to go up my arm, right? So up the neurons up my arm, and it's going to get up into my spinal cord. And then when it gets up into my spinal cord, it's actually going to make a quick jump and jump right over the motor neuron. That jump is done through what's called the inner neuron, right? So that jumps across into the inner neuron and right back down. My brain didn't even receive the signal that it's hot before my hand pulls off. That's a cool thing about a reflex, right? Sometimes, not always, but sometimes the brain doesn't even need to be involved. Now, your brain will pick up on it and say, Oh, that was hot. And you give that verbal response or other choice words that may be coming out about when you burn your hand. But those are not the reflex. The reflex is this, the aching your hand back. And you did that without thinking, right? And your brain then interprets that you've got something hot, you know, because the signal is still going up there. But in order to keep your skin intact, you have the reflex happen quicker by using that inner neuron. So it shortens the reflex arc, if you will. So those three things, the sensor neuron, the motor neuron, the inner neuron, all sorts of things involved if we really get detailed, those form the reflex arc. Those are your three basics. So that's the reflex. We're going to look at reflexes in a little kind of a little more detail.