 So let's start by comparing the endocrine and the nervous system. So what we know is that they're both integrators. So if you come across a nervous system like brain spinal cord part, you know already that that is an integrator in a communication pathway. The endocrine system, if you come across an endocrine gland in some kind of communication pathway in your body, you know that that endocrine gland is going to be an integrator. It's going to be receiving information and deciding what to do. The signal in the endocrine system, and this is probably, you're probably like, of course that's the signal. And I have to look for the perfect color of orange because that's just what I'm feeling right now. It's got to be orange. The signal for the endocrine system is the hormone. Every time you talk about hormones, you're talking about the endocrine system. The nervous system, we have actually two flavors of signal type or signal information, and we talked about this a little bit in the anatomy. We have an electrical signal, which is called the action potential. And I'm just going to give a little shout out to physio because you will learn all about the action potential in physio. I want you to know that that's electrical. And I'm just going to say electrical. The nervous system also has a chemical signal that is involved, and that's a neurotransmitter. Neurotransmitter, not to be confused with a hormone. So neurotransmitters are chemicals that are barfed out into the next cell in line in a neural communication pathway. A hormone is a chemical, so neurotransmitters and hormones are both chemicals, but the hormone is barfed out into the bloodstream. In fact, that's the definition of a hormone. It is a chemical that is dumped into the blood and travels through the bloodstream to affect a distant target. In general, endocrine system is slow. The message, the speed of transmission, is how fast does the message get to the target? In the endocrine system, the message has to travel through the blood. So really, I mean, it's all relative because your blood actually circulates one entire time through your system in like a minute. It's a minute for you to pump all your blood through your system. So I don't know, in Windy Land, I'm like a minute, that's fast. But a minute to travel through your whole body versus the nervous system, the electrical message. I just have to write this down for you. I can't ever remember this number. What? 268 miles per hour? For those of you out there who aren't crazy about this United Statesians using this whole like miles and what? That's equal to 120 meters per second. That's fast. The message travels down the neuron that fast. The electrical message travels that fast. Endocrine system, we have to dump it into the blood before we get there. You know what? This is interesting because the target of the endocrine system is considered general, like versus very specific. And let me explain that for you. In the nervous system, the target is someone who synapses with a neuron. Do you agree with that? There is like, who could it be? It could be an effector. It could be another neuron. It could be a gland. It could be an endocrine gland. We can actually have, in fact, often have, nervous system and endocrine system talking to each other. It's specific because if you're not touching that neuron in some way, like if that neuron doesn't have extensions that are reaching out and touching you, you're not going to get the message from that neuron. Endocrine system, as long as you have the receptor for the hormone, not everybody does. Not every cell in your body has the receptor. So it's specific in terms of you got to have the receptor to be affected, but anybody who has the receptor is going to be a potential target of the endocrine system. And since you're dumping chemical into the blood directly, like, here, take some. You just throw in a whole bunch of hormone. That hormone goes through the bloodstream and affects a whole bunch, like anybody who has the receptor. Okay, so let's just say got receptor. If the answer is yes, you're going to be affected by the endocrine system. Our question for the nervous system is going to be touching me? If you're not touching the neuron that is sending the message, you're not going to get the effect. You're not going to get the message. Okay, so what is the speed of the effect? So let's make sure that the effect speed. Interestingly enough, the endocrine system effect is often slow. Sometimes the endocrine system, like a hormone, will initiate protein synthesis and draw yourself back to your general bio days when you're thinking about protein synthesis and how long does that take to find the gene, go through the whole process of transcription, then take it to the ribosome, go through the whole process of translation, build a protein, possibly send it to the endoplasmic reticulum, where you can actually get it folded and then throw it out to the Golgi body where it gets packaged in a nice little... I mean, there's this whole process. Until you actually exocytose or barf it into the blood, are you going to even begin to see an effect? Nervous system? You're going to see an effect almost instantaneously. Here comes the message, electrical message, tap, and voila, whoever you tapped is going to respond. You can shock yourself. Those little, what are they? They're like belly flatteners, and you stick a thing on your stomach, and then it like contracts your muscles because it shocks them. Do you know what I'm talking about, and it's supposed to make your belly flat? I wonder if it works. But the idea is that the little electrical stimuli are kind of like electrical action potentials and the muscle, it's like the muscle got the message. Muscle gets the message, muscle contracts. That's fast that that is happening. Okay, so I better write that down. The effect is fast. As soon as you get the chemical dumped on you, you initiate a response. Endocrine system takes a while. That's kind of a general comparison, but we're going to start out looking at, we're actually going to spend an entire clip talking about a nervous system structure that we've already dealt with, the hypothalamus in the brain because it is such an important part of endocrine function, we need to deal with it as well. Hypothalamus coming up.