Pituitary Gland Anatomy - Structures and Functions

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I'm gonna explain the structure and function of pituitary gland the pituitary gland is is an endocrine gland that is slightly pinkish in color and this pea-sized gland is about 1.3 centimeter in diameter and its weight is only 0.5 gram in humans this pituitary gland is attached to the hypothalamus of the brain via a stock called pituitary stock or you can say it's another name is infundibulum so this pituitary gland is connected to the hypothalamus by a stock called infundibulum hypothalamus is a portion of a brain that has where that has many various functions one of its most important function is is to link the central nervous system with the endocrine system of the body.

Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions
Pituitary Gland Anatomy Structures and Functions

So coming back to the pituitary gland so the pituitary gland is the complex organ of the human body which which is the source of chemicals that play a key role in many functions this pituitary gland is divided into two separate lobes that is anterior lobe and the posterior lobe the anterior lobe of the pituitary gland is connected to the hypothalamus by portal blood vessels only a few millimeters long through these vessels pass a group of regulating hormones which are produced in the hypothalamus these releasing or inhibiting hormones regulate and coordinate the anterior lobe of the pituitary to initiate the production or suppression of specific hormones whereas the posterior lobe of the pituitary gland is smaller than the anterior lobe and it stores only two hormones that are secreted by hypothalamic neurons these neurons are called hypothalamic neurons because it connects the posterior lobe of the pituitary gland to the hypothalamus directly via infundibulum and these neurons produces hormones that are released from posterior pituitary glands.

Remember the posterior pituitary gland stores hormones and do not secrete any hormones or do not any produce hormones it's just two hormones that are produced by the neurons from the hypothalamus and the posterior pituitary is smaller than the anterior pituitary so now let's talk about the functions of the pituitary gland first is anterior pituitary gland the anterior pituitary gland secretes eight type of hormones and the first hormone is human growth hormone as you can see the human growth hormone stimulates the growth of the body cells specially of bones of limbs and it also stimulates the protein synthesis and inhibits protein breakdown also it carry-outs hydrolysis of fats and retards the use of blood glucose for ATP production next the second hormone is thyroid stimulating hormone or TSH this thyroid stimulating hormone targets the thyroid gland of the human body that is located in the neck region and this thyroid stimulating hormone controls the secretion of the thyroid hormones or the hormones that are secreted by the thyroid gland mainly the thyroxine hormone third hormone is adrenocorticotropic hormone or ACTH this adrenocorticotropic hormone targets the adrenal cortex region of the adrenal glands that are located just above the kidneys
 this hormone controls the secretion of the adrenal cortex regions of the adrenal glands basically the secretion of adrenaline hormone fourth is melanocytes stimulating hormone or a message it targets the melanocytes in this present in the skin of the human body and it stimulates the cutaneous pigmentation by dispersion of melanin granules in the skin fifth hormone is prolactin hormone prolactin is a unique among the pituitary hormones as it is under predominant inhibitory control from hypothalamus so this producting hormone stimulates the milk production in the mammary glands of the females and also participates in the control of reproduction osmoregulation growth and metabolism of the human body.

So now the sixth hormone is follicle stimulating hormone or FSH this follicle stimulating hormone stimulates the process of spermatogenesis that is the production of sperms in males and the growth of ovarian follicles or you can say the process of evolution the seventh hormone is interstitial cells stimulating hormone or IC SH this interstitial cells stimulating hormone secretes the controls the secretion of the testosterone hormone in males its target organ is testes in the males and testes produced testosterone hormone and this IC SH interstitial cells stimulating hormone controls the secretion of this testosterone hormone in males so in the last hormone produced by anterior pituitary gland is luteinizing hormone luteinizing hormones is associated with the follicle stimulating hormone and it triggers the process of evolution with the FSH follicle stimulating hormone and it also stimulates the conversion of ovarian follicles into corpus luteum in females so that's all about the anterior functions of the anterior pituitary gland now let's talk about the functions of posterior pituitary gland.

As I've said earlier this posterior pituitary gland does not secrete or pedal produce any type of hormones but it stores the two types of hormones that are produced by hypothalamic neurons of the hypothalamus the first hormone is oxytocin this oxytocin stimulates the contraction of uterine muscles during the birth and initiates the ejection of milk from the mammary glands of the female and the second is antidiuretic hormone or it's another name is also the suppressant it is also called vasopressin and it stimulates the reabsorption of water and from the digestive system and rid and reduce the urine secretion and it stimulates the constriction of blood vessels and thus increases the blood pressure of the human body so that's all about the structure and function of pituitary gland of the human body.


I have the pleasure to talk to you about one of the most important endocrine glands of the entire body although it's not fair to say that because each of the glands are important in their own way but if I were to play favorites I might I might make this one most important it's a little tiny gland and let's jump right into this conversation it's a little tiny gland at the base of your brain and it's called the pituitary that's right the pituitary gland is our discussion today out of all the glands that make up the endocrine system pituitary gland is going to be really important and so here's the actual location right here pituitary it's on this little stock right there right below the inferior to the hypothalamus and that's going to be important because we're going to see in this this video the hypothalamus in part controls the secretion or not secretion of pituitary hormones and so what's fascinating about the pituitary gland though it's the size of about a pea so a green pea and it sits on the stock right here we can actually break it up into into two lobes and they're rather distinctive one of them is towards the front or interior so this is the front of your of your head and this is the posterior so anterior posterior so there's a anterior lobe and a posterior lobe and so there's distinctive hormones that are coming from each of those lobes so that's important so something to consider so here's a here's a pitcher that's that might get your attention this is a cadaver that's been sliced in half and you can see the brain right here I thought you'd enjoy this because you can literally see the pituitary gland right there which is right below the hypothalamus and the pituitary gland sits right above these two sinuses right here this is the the ffs boyd sinus and the sigmoid sinus right there so that's it's it's actual location the pituitary now when I say it's an endocrine gland just for everyone to be on the same page what I mean by that is that it that it's a gland that's capable of secreting and what it's secreting our hormones which are chemical messengers that are specific to target cells and those secretions those hormones are traveling in the bloodstream so this is what we're is what we're talking about so let's let's discuss what I was mentioning earlier about that hypothalamus that hypothalamus which is sitting superior to the pituitary gland produces some releasing hormones so these hormones will travel in the bloodstream to the pituitary gland causing them directly will cause the interior in particular pituitary gland to secrete its hormones so those are releasing hormones from the pituitary from sorry from the hypothalamus.

So let's take a look at that so here we are in the hypothalamus and here is your typical neuron although there are no typical ones but it's a neuro secreted Tory cell so it's capable of secreting hormones so those releasing hormones as they're generally described travel into the bloodstream they don't have to go very far and they travel down these blood vessels down to the anterior lobe so this is gonna be the anterior lobe so it's a little switcheroo from the picture I showed you before so this person would be facing in that direction so this is the front the anterior lobe now notice the blood circulates through all these cells and these cells are the glands a gland is no more a collection of cells that are specialized for secretion and in this case it's the anterior pituitary gland and so these are the cells that are going to be secreting and what they're actually secreting are these little tiny green dots which are the hormones and that's going to be diffusing into the bloodstream and being carried away through the rest of the body wherever they're going so the blue dots are the releasing hormones from the hypothalamus and then the anterior pituitary gland is releasing the various hormones and so our discussion today it's going to be about what are those hormones like what are hormones of the anterior lobe.

Now take a look at the pituitary the posterior lobe it's kind of interesting to draw your attention to that notice here the secrete Ettore nerves of the hypothalamus actually extend from the hypothalamus this is the axon right here extend all the way down the connecting stalk into the posterior lobe the truth is that the posterior pituitary gland is merely just the neurosecretory cells of the hypothalamus because in fact they produce two hormones something called ADH and oxytocin we'll talk about that but those go directly from the posterior region right into the blood and so there's the posterior pituitary hormones and then here's the anterior pituitary hormones so the anterior is a little bit larger as well and so let's first discuss now we switched off so now we're looking this way this is the anterior lobe and so here are the releasing hormones and then what are these what are these hormones now each of these are different these little blue dots are interior pituitary gland hormones what are those blue dots and so these are the cast of characters now you know just a caution if you don't mind don't become overwhelmed by the magnitude of this or don't be discouraged by acronyms acronyms are helpful especially when the words are very long we could shorten them but also it's all about familiarity and the more that you're comfortable with the more you work with each of these hormones the more that you spend time studying them it all becomes very straightforward but I'm gonna come very strong and just sort of name them so it might be intimidating in terms of like remembering through through your memorization but it's not about memorization it's about just
 understanding and enjoying these hormones.

So one of the first hormones is going from left to right that the pituitary anterior pituitary produces is pretty famous it's growth hormone since we're discussing human I don't have to but I will I could put an H in front of it so HGH human growth hormone there's other hormones that people are like bull vine growth hormone is often used in development of of cattle to make sure that they're they're growing larger for a variety of reasons for for for purposes to to produce large quantities of meat but in this case human growth hormone and its target is that of the bones that it causes bones to to grow and I think that makes perfectly good sets and so this growth hormone sort of tails off as we get a little bit older but it's certainly prominent in our adolescence and then this one right here prolactin prolactin is a hormone that is particularly important in females and it stimulates the mammary glands to actually produce milk which the main sugar of milk is lactose so thus the name prolactin these two hormones right here follicle stimulating hormone or FSH or luteinizing hormone or LH are considered to be gonna tropen gonna tropen meaning going toward tropism meaning towards something go nadz or reproductive organs so gonna tropen hormones because their target are testes and ovaries and so this will come up in conversation in detail when we look at the systems of reproduction in both male and female but briefly follicle stimulating hormone causes the follicle in the ovary to mature once a month and it prepares it to ovulate on what is the second week generally of a four week reproductive cycle in the ovary and this hormone luteinizing.

Hormone is particularly important because it spikes up at around a fourteen which initiates ovulation which results in a group of cells in the ovary that remained the egg is released during ovulation but the group of cells that remain are called the corpus luteum and so that's why it gets that name lute knighting Norma - it's a yellowish structure that produces its glandular and it produces estrogen and progesterone the corpus luteum thyroid stimulating hormone as the name might imply it stimulates the thyroid to start secreting so there you have it so the thyroid gland is under control of the pituitary same with same with the testes and ovaries so what they're doing is actually in control of from the brain it's fascinating this one's a Kola an ACTH or adrenal cortical tropen hormone so courted the cortex of the adrenal gland is the outer coating of the adrenal gland we'll be studying that a little bit later in a separate video but this is a hormone that travels to just the adrenal cortex so it's adrenocorticotropic hormone that's what that stands for and then Milano site stimulating hormone or FSH stimulates the melanocytes - to produce endorphins you may have heard of this chemical before this is a it can be a hormone and it is involved in deadening pain receptors and so it has sort of a euphoric kind of type of sensation endorphins alright and so what's interesting is i'm going to just go through some of these hormones a little bit more detailed and describe to you what they are chemically and and and refresh you perhaps on what they do so human growth hormone hormone is a protein now remember hormones could be classified either as being a steroid or a non steroid so this would be non steroid since it's a protein what does it do it stimulates growth both muscular and also bone development as well.

So it causes these cells to divide and to manifest and proliferate and it also affects the metabolism responsible for that growth so as it turns out there's two types of disorders that that can come from human growth hormone if you look at it this way in terms of everybody needs just the right amount so if you have excessive amount of growth hormone that can be a problematic if you have too little of growth hormone that could be a problem as well and so what we call some of these things there are different names with different syndromes like gigantism you might imagine that is excessive growth hormone.

So that's it's a hyper there's a lot of it and so here's an individual that's like sort of say abnormal that you know you know I'm not sure what normal is but certainly a phenotype that is certainly on the high end pun intended and then here's oh here's a woman who has excessive gigantism so an abundance of growth hormone now the contrast to that is hypo pituitary dwarfism meaning that you have a low amount and usually this occurs genetically and it can be treated a little bit with with growth hormone but overall it there's not much that can be done about this hypo pituitary so it's a hormone human growth hormone deficiency so prolactin I mentioned before influences the mammary glands and it's a protein it's produced by the all of these our anterior pituitary gland hormones it stimulates milk production so this is particularly important during pregnancy and also particularly important after the baby is born so for lactation and it helps the secretion of milk and so these go into tropen hormones and I mentioned this before like going toward the gonads so this is going toward the gonads gonads meaning ovary and testes so these are glycoproteins again sugary proteins not non-steroid follicle stimulating hormone also in addition to maturing the the egg during the ovarian cycle it also influences the production of of the egg itself causing the follicle to mature more about that later and again luteinizing hormone stimulates the ovaries and testes now you might be wondering I mentioned follicle stimulating in the ovary and luteinizing hormone on the ovary these similar hormones are present in male but they do different things like for example follicle stimulating hormone luteinizing hormone could also be called interstitial cells stimulating hormone which causes the testes to start producing sperm for example spermatogenesis at puberty this is particularly important and also can stimulate the testes especially the cells in between these tubes called seminiferous tubules they're called interstitial cells to stimulate testosterone and so more about that later those are a little complicated but I'll just say that these are hormones that are produced by the anterior lobe of the pituitary gland and they go to the open to the gonads we have thyroid stimulating hormone which again is a glycoprotein and it stimulates the thyroid gland to produce its thyroid hormones and adrenocorticotropic hormone meaning it's going toward the adrenal cortex and it's a and it's a peptide peptide is a little different than a protein because it's a it's very small and so if you recall proteins are made up of polypeptides many of them so this is a very tiny hormone and it stimulates the cortex to secrete its hormones which are glucocorticoids.

In other words hormones that influence glucose metabolism melanocytes stimulating hormone plays a role not only in Milano site production but it also plays a role in fat metabolism as it turns out this is fairly recent discovery and it's also a peptide mhm mhm I'm sorry MSH and then endorphins are small peptides and what's interesting about these endorphins is that they're highly studied because to inhibit pain is very important to us in terms of medicine it's unfortunate that people occur and have pain and sometimes chronic pain.