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Thyroid Gland Microscopic Anatomy

Endocrine System part 1 Glands Hormones Crash Course AP 23

I’ve invited you all here today because I wanted to talk to you about some ugly stereotypes that are going around. I’ve been hearing a lot of unfair, unseemly, and unscientific generalizations being made lately. And they mostly have to do with sex. And your hormones. People have a nasty habit of equating “hormonesâ€� with a particular set of behaviors and conditions, most of which have to do with reproduction, or sexual development, or acts that include what my brother John has referred to as “skoodilypooping.â€� For example, people will say that “hormonesâ€� are why Kevin has zits, and is being all moody,.

Or why Hannah, who’s three months pregnant, just cried watching a commercial for car insurance which, let’s be honest, I do that too. Now, I’m not saying that hormones aren’t at the root of sexual attraction, or zits, or occasional bouts of extreme emotion, because they are. That’s just not all that they do. Not even close. When people talk about “hormonesâ€� in the contexts that I just mentioned, what really they mean is quot;sex hormones.quot; But sex hormones are just one kind of hormone that you have coursing through your body right now.

In fact, there are at least 50 different types of these chemical messengers at work in your body at this very minute, but only a very few of them have anything at all to do with sex. The truth is, from birth to death, just about every cell and function in your body is under your hormones’ constant influence. They’re floating through your blood, regulating your metabolism, your sleep cycle, your response to stress, and the general and incredibly important overall homeostasis that keeps you not dead. Some hormones are just there to make other hormones trigger even more hormones in a kind of chemical relay race that biologists refer to, rather elegantly, as “cascades.â€�.

These hormones run through you no matter what your mood is, or whether you have zits. So the reality is: We’re all hormonal . all of the time. OK, to begin to understand our hormones and the endocrine system that produces, releases, and reabsorbs them we have to step back and take a broad view. Not just by emphasizing that sex hormones aren’t the only hormones you have but also by looking at how your hormones interact with your other organ systems. Because, if anything, your body has two bosses two complementary systems that are constantly shouting instructions over each other, to all of your bits and pieces.

Both your endocrine system and your nervous system are constantly trafficking information around your corpus, gathering intel, making demands, controlling your every move. They just have totally different ways of doing it. Your nervous system uses lightningfast electrochemical action potentials, delivered by an expressway made of neurons to specific cells and organs. But your endocrine system prefers a slower, wider stream of data. It secretes hormones that travel through your blood NOT through neurons so they move more slowly, but they also produce widespread effects that last a whole lot longer than an action potential.

Now, compared to your heart or brain or other, arguably more glamorous organs, your endocrine system’s organs and glands are kinda small and lumpy. They’re also rogues instead of being all nestled together like in your other organ systems, these guys are scattered all over the place, from your brain to your throat, to your kidneys, to your genitals. A gland is a just any structure that makes and secretes a hormone. And the master gland in your body is the pituitary, which produces many hormones that signal other glands like the thyroid, parathyroid, adrenal, and pineal glands to make their own hormones. The endocrine system also includes a few organs like the gonads, the pancreas, and the.

Placenta in pregnant women all of which have some other nonhormonal functions and are made up of multiple tissue types. And technically the hypothalamus in your brain is in the endocrine club too, since in addition to all of its busy brain duties, it does produce and release hormones. So, thanks to these glands and organs, you’ve got all these hormones diffusing through your blood, doing all sorts of different things, but the thing to remember about them is that a hormone can only trigger a reaction in specific cells their socalled target cells that have the right receptors for it. So, just like some keys can open many locks, while others only work with one, so too can.

The hypothalamus and pituitary gland Endocrine system physiology NCLEXRN Khan Academy

OK, so today what I want to talk about is endocrine control. And in order to talk about endocrine control, I need to talk about two major glands. First, the hypothalamus I’m going to draw that in here and then in this enlarged image right here, this is just a blownup view.

Of the hypothalamus. And then the next major gland that we need is the pituitary gland. And the pituitary gland is the gland that dangles right below the hypothalamus. And you can see that the hypothalamus is.

A structure right here in the forebrain and the pituitary dangles right beneath it. And as a member of the brain, the hypothalamus receives neural signals from the brain and from the peripheral nervous system, and it funnels those signals to the pituitary gland, which ultimately controls the other endocrine glands and our body’s hormonal response to the environment.

And there are two different parts to the pituitary gland. You have the anterior pituitary gland, and then you have the posterior pituitary gland. And the hypothalamus interacts with the anterior and posterior part in two different ways. And so it interacts with the anterior pituitary gland, primarily through the hypophyseal portal system which, I’ve kind of drawn in here.

And the hypophyseal portal system is a capillary system, so little blood vessels that flow between the hypothalamus and the pituitary gland. And the hypothalamus secretes hormones into this little system, and they go down and they signal the pituitary gland, and so that would be an example of a paracrine signal,.

Or a really regionallyacting single. And so one example of the hypothalamus hormones that signal the pituitary gland is gonadotropinreleasing hormone, or GnRH. And gonadotropinreleasing hormone is going to go down to the anterior pituitary, and it’s going to stimulate the release of folliclestimulating hormone and luteinizing hormone.

So FSH and LH. And these hormones are going to travel down to the gonads in the male, the testes, and in the female, the ovaries and they’re going to stimulate the gonads to release their hormones. Another example of how the hypothalamus controls the pituitary gland, which ultimately controls the endocrine glands, is corticotropinreleasing.

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