 It's my favorite, because we get to talk about pathways. And the reason why we're talking about pathways is because the nervous system coordinates pathways, communication pathways, and so does the endocrine system. Comparing and contrasting these two kinds of pathways, do that, like I should write my exam right now because that's a phenomenal exam question, like a five-pointer would be compare and contrast nervous and endocrine pathways. Somebody remind me that I said that so I can actually put it on the exam. Big similarities, very significant differences. Both endocrine and nervous pathways begin with what? Stimulus. And tell me, is the stimulus an anatomical structure? I'm going to get cranky if you try to tell me that the stimulus is an anatomical structure. The stimulus is, like, totally not an anatomical structure. It's something that initiates the pathway. An interesting difference between nervous system and endocrine system. Nervous system, the stimulus often is outside, something external, something in the environment. If it is, if the stimulus is being detected by somatic sensory receptors, it is something external that is causing the message. In the endocrine system, it's always inside. And I say that knowing full well that maybe there is an endocrine, like a stimulus to the endocrine gland that actually does come from the outside, but I don't think so. So if you think of one, tell me because I want to know. Both of them start with the stimulus. Both of them end with what? A response. Is a response an anatomical structure? No, never. Responses, what happens? Both of them have these non-anatomical things. Let's do the nervous system side first because that will, like, remind us of what is familiar. The stimulus is, okay, I've got to find my perfect orange. The stimulus is picked up, oh, good God, I don't think I can use that color, I'm sorry. That's not going to work for me. Let's try, that'll work. Nobody knows. I know it doesn't matter. Stimulus comes in, okay, and is picked up by what? Anatomical structure, a sensory receptor. That's an anatomical structure. The sensory receptor translates the stimulus into what? A message, an electrical message via an afferent path. Do you agree with that? And the afferent path was what? Some kind of nerve. Do you agree with that? The afferent path takes the message to whom? Do a neural integrator, or let's just say integrator because we will see that pathways can get totally complicated and neural pathways and endocrine pathways can actually interact with each other. The integrator receives the information, processes it, and generates an output signal. The output signal goes how? Through the afferent path. Do you agree with that? Of course you do, because that's how it rolls. The afferent path delivers a message to whom? The effector. The effector generates the response, okay? That's super familiar, right? All right, let's talk about the endocrine system. The stimulus, the stimulus is usually going to be something inside, like something almost in the blood that is going to stimulate the endocrine system. And the fact is that the thing that distinguishes it is that, yes, we sort of have a sensory receptor, but we sort of don't. Now watch what I'm about to do. I'm taking this sensory receptor and the afferent path and the integrator and putting them all in one box, because the sensor, or the sensor, like what you would think of as a sensory receptor, they actually call it a sensor in the endocrine system. The sensor is the integrator. So the stimulus comes in and it, what? It stimulates the sensor. The sensor is the integrator and what is this? What is this if we're in the endocrine system? This is endocrine, like, how am I going to label this? Endocrine gland or cell. There is no other sensory receptor. There is no afferent path. And I've always thought of endocrine glands as like they're just integrators. But it's like how does the integrator get the message to do something? There's a sensor on the integrator. And the sensor picks up the stimulus, whatever it is, low blood calcium, high glucose concentration, more metabolism needed, like something triggers this. The integrator senses that. After that, the integrator is going to actually dump or create an output signal. Now I'm going to label it like that. I guess I'm in the right color because the output signal is the afferent path. But what was true about what is, like, tell me what's the nature of the output signal? It's a hormone. This right here is a hormone. Where does it get dumped? More pictionary. It gets dumped into the blood. So the integrator, the endocrine gland, dumps hormone into the blood. That hormone is the output signal. As far as I'm concerned, you can think of that as an afferent path. It's like the same thing. They don't call it an afferent path because it's not directional. It's in the blood. So it's literally going to have access to going anywhere. So there's no directional information with output signal. There's no directional information with endocrine system, which is why they call it an output signal. Here goes the message out into the world. Afferent path is directional from central nervous system to effector in that direction. An afferent path is never any other direction except integrator to effector. The output signal goes all over the body through the bloodstream. There's not an actual direction associated. I hope that makes sense because I said it about 8,000 times. Now, guess who's the same? The output signal heads out to a, I want to call it an effector because that makes it consistent, but often in the endocrine system, we call it a target. And we can mess with that in physio. The effector generates the response. Now, it's actually not crazy, is it? Like that, like the only weird thing is that the sensor is the integrator and then we've got a little bit of different terminology, but I could totally see this on exam and quizzes. Like we'll throw this thing on the quiz. So get comfortable with that and be able to compare and contrast, be able to throw in specific, never mind. I'm not going to make you throw in crazy specifics. Maybe I will by the time I actually have class because yeah, I'm delirious because I'm nocturnal. All right, there's something I was going to say, oh, you can stack them. What? You can stack these things. So you could have a stimulus initiate a nervous system response, send a message to an integrator, brain spinal cord, integrator, brain spinal cord, hypothalamus could send a message to the endocrine cell. The endocrine cell, the ant pit, is the sensor, receives the message, has the right receptor, whatever receives that message and then is the integrator generating the hormone, which gets dumped into the blood, heads on out to an effector, awesome, or it can head to another freaking endocrine gland. Are you kidding me? Like we can pile these things on and get very complex pathways. Do you think there are any complex pathways in your body? Those of you guys out there who are taking anatomy and physiology and doing these things together at the same time, like you guys are getting to actually go into the physio at the same time as your anatomy, I have to wait. I'll try to be patient while I'm waiting and in the meantime, you probably want me to stop talking. What? You do? You don't want to just listen to me all night? I mean, it's only 1.30 in the morning. We could keep going. Yeah, hopefully it's not 1.30 in the morning where you are. All right, endocrine system rocks. I will holla at ya later.