Adrenal Glands

by Jason Amores Sumpter
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before getting to the adrenal glands that sit on top of the kidneys. I want to mention the kidneys. Own hormone erythropoetin. This hormone is secreted by the kidneys to stimulate red blood cell production in bone marrow. Now the adrenal glands sit on top of the kidneys, and like the kidneys, they have this to layer structure where they have an outer cortex and an inner medulla. Now this outer cortex is an endocrine gland, and the inner medulla is actually a neuro endocrine gland. The adrenal cortex is it called, as it's called secretes, mineral core dacoits and glucocorticoids. Now the hypothalamus is going to secrete C. R. H. And that stimulates the pituitary to secrete a C T. H. And that's going to stimulate the release of these glucocorticoids thes glucocorticoids are named because they're involved in glucose metabolism. But don't let that fool you. They do lots of other stuff, too. Now the one to know is cortisol. Cortisol is definitely the most important glucocorticoids. It's a steroid hormone involved in long term stress responses and fight or flight responses. Now the mineral core dacoits are steroid hormones that they're going to cause the kidney. Thio or they're going to help the kidney regulate water balance and electrolyte balance. And this is gonna be, you know, the main hormone to know is Aldo Austrian. And if you want to know more about that, check out our lesson on Osma regulation and the kidneys. Now, the adrenal medulla is the inner gland that's gonna secrete epinephrine and norepinephrine in response to synaptic signals. Because this is a neuro endocrine gland. Now, epinephrine, you may have heard called adrenaline, but it's the same hormone and same thing with norepinephrine, which is sometimes referred to as nor adrenaline. Now, epinephrine is in a mean hormone, and it's gonna be involved in stress response. Uh, and we're gonna talk about this special stress response right now. The fight or flight responses of short term stress response. It's gonna be triggered by a division of the peripheral nervous system called the Sympathetic Nervous System. Now, the hypothalamus is essentially going to send synaptic and endocrine signals to the adrenal gland in response to some type of perceived threat. Like you see happening here, where this dog and this cat kind of wigging out when they see each other right there. Either about Thio throw down and scrap right now or probably run away in either direction. That's, you know, typical fight or flight response. Now the synaptic signals they're gonna cause the adrenal medulla to secrete epinephrine and norepinephrine. And these were gonna lead Teoh a variety of physiological changes. And the, um, the endocrine signals are going thio cause the adrenal cortex to secrete cortisol. Now, these, uh, these were gonna affect the body in in many different ways. But the main ideas that they're going thio lead the body, uh, to basically prepare toe. Either you fight for your life or run like heck And you know, the effects are gonna involve things like increased breathing rate, you know, to get more oxygen in your blood to get more oxygen to your muscles so that you can either, you know, uh, fight for your life literally or, you know, Runas fast. You can. It's also going to do things like increase blood pressure. It's gonna dilate your pupils, and it's going thio, increase your blood glucose levels, and that is going to help provide mawr glucose for your brain and provide more glucose, especially to your muscles, which are gonna need it. Now. The stress response is controlled by this famous negative feedback loop known as the H P a axis or hypothalamic pituitary adrenal axis. And this is a negative feedback loop that's going to control stress levels, particularly with cord is all you know, think cord is all when you're thinking about these levels. So we know the hypothalamus of secretes CRH and that causes the anterior pituitary to secrete a C T. H, which causes the adrenal cortex to secrete that stress hormone. Cortisol is gonna jump out of the way here so you can see this image better and the when cortisol is secreted by the adrenal cortex, it's actually gonna feedback negatively to both the hypothalamus and the pituitary gland and shut off the release of CRH and a C T. H. Now this is important because over doing it on the stress response can lead to some negative consequences for the body. For example, it can lead thio suppression of the immune system, which is obviously very bad. Now, if you're a C T h secretion really gets out of control, you can have this persistent stress response knows Cushing's disease, and this is bad news has a bunch of different negative effects on the body. Um, for example, high blood pressure, you know, just all around. Not what you want. You stress response is something that's good in the short term, but needs Thio, you know, be controlled very tightly so it doesn't run amok in the body. With that, let's go ahead and flip the page.