 You thought you were finished with me this week, huh? Nice try. More video lectures. OK, so this lecture is, the whole point of it is to talk through the RAT lab. Now, the RAT lab is complicated. I give you a paper that has everything that you need to know in it, but we're new physio students and we're new to the idea of feedback loops and we're new to the idea of chemicals, having effects on organs. So I think that it's totally fair for me to help you see kind of the big picture and why we're doing this and help you fill out parts of this lab so that you can come to class ready to figure out what hormones treated what rats. Piece of cake. So here's how we're going to do this particular little mini lecture. I hope that you have gone through and answered all of these questions. I'm not going to deal with the questions. And the reason why I'm not going to deal with them is because the information that you need to answer these questions is right here in this text. I am going to focus in on this chart right here and the relationships that we can see when looking at three different hormones, thyroid hormone, cortisol, and testosterone. We're dealing with six hormones in our little experiment right here, but all six of them actually fall into one of these three pathways. So we're going to talk about thyroid, cortisol, testosterone. Are you cool with that? All right, so I'm going to come back to this chart, but the whole point is that I'm going to help you fill out this chart. This chart is the magic chart. And the more time you spend filling it out and understanding why you think a certain thing, the easier the actual lab is going to be when you're recording data from your little paper rats. So let me just explain to you what this chart is asking you for. Basically, you're going to take a hormone, a hormone that you've been exposed to in this lab handout. You're going to look at that hormone and you're going to speculate. If I dumped this hormone into a rat chronically over three weeks and just gave them massive amounts of this hormone, what would it do to the pituitary gland? And we have information in the lab that will help us answer that question. If I dumped this hormone in, what would it do to the thyroid gland? We have information that will help us answer that question. If I dumped this hormone in, what will it do to the adrenal gland, the thymus, the testes, the prostate, and what will it do to body weight? You're going to go through and speculate. Some of these, this hormone you might decide, dude, is it going to have an effect on the thymus? Like how would thyroid releasing hormone affect the thymus? And then you're just going to put a little x. It doesn't do anything for that. Or maybe you'll even just leave it blank. Either way around it is totally fine. But the end of the story, you're going to get this whole thing filled out, which is really fantastic. And I'm going to help you do it. So we're going to start out by looking at the thyroid gland and figuring out what we think about how the thyroid gland will work. See you in a second.