Live Tutorial: Endocrine

ok everyone welcome to the 2 p.m. tutorial this week week 9 being the endocrine system we're gonna focus on hormones and glands and we're going to focus on some very specific hormones and glands I think the best way to do it is a top to toe sorry I'll turn that off let me just fix that up I think the best way to do it is a top to toe mechanism so we basically start at the brain and when I say start at the brain I mean start at the hypothalamus but before we do all that couple things if you have any questions you just pop it down in the chat and I'll try my best to answer them you need to understand the difference between the endocrine system and the nervous system right and so remember that the nervous system which you've spoken about before you know you've got a neuron and we know that neurons like to release neurotransmitters and these neurotransmitters that will cross the synapse which is a very small gap and they will bind directly to receptors on either another neuron for example or on cells right so when you look at nervous tissue it is a mechanism of communication it releases neurotransmitters and neurotransmitters are chemicals right we went through a big list of these neurotransmitters can we go through the adrenal gland and the pancreas very confusing in lecture not a problem a tea I'll make sure I definitely will hopefully I'm pronouncing my tea Maddy I'm sorry if I mispronounced your name so when we look at the communication network of a neuron releases neurotransmitters chemicals that very specifically bind to something very locally which is either another neuron or a cell right now when we look at the endocrine system it's a cell or a collection of cells right there's a cell that's a little nucleus there that release chemicals just like these except these chemicals are called hormones but these chemicals don't just bind to something really close to it it actually jumps into the bloodstream and these hormones or chemicals jump into the bloodstream and they travel to different parts of the body now what that means is the difference between the nervous system and endocrine system is they're both mechanisms of communication they both use chemicals except the chemicals in the nervous system are called neurotransmitters and the chemicals for the endocrine system are called hormones neurons and neurotransmitters are very fast the endocrine system is slow the nervous system is very direct it goes from that to that the endocrine system goes from that to everywhere in the body alright so the is there some of the major differences between the nervous system and endocrine system hi dr. Mike sometime throughout the tutorial can we please go through the specific hormones of the anterior pituitary I promise you we will because it's a lot and it can be a little bit confusing the crux of today's shoot will be the hypothalamus and pituitary glands and the hormones they release and what exactly they do because what you're gonna find is in your end of trimester exam most of the endocrine questions will probably be around the hypothalamus and pituitary gland maybe who knows I do because I wrote it alright let's now have a look at a couple of things when we look at hormone so I said that they're chemicals but these chemicals can either be amino acids they can be proteins which we now adjust big stretches of amino acids that have been folded into three-dimensional structures and steroids so the three different types of hormones you can have are amino acid proteins and steroids all right here's the thing when we look at the way that they bind to their receptors because obviously they're chemicals in order for a chemical to have an effect it must bind to a receptor right amino acids and proteins if here's a cell that has a receptor for one of these hormones right it's either an amino acid-based hormone or it's a protein based on it doesn't matter what's going to happen is that it needs to bind to a receptor on the outside of the cell and the reason why it needs to bond on the outside of the cell is because amino acids and proteins they can't freely move into and out of the cell so in order for it to tell the cell to do something it must bind to a receptor on the outside binds to extra cellular receptors right and then this signals transduced inside and then it tells the cell to do its thing whatever that may be we got a question I was confused on the structure of the posterior and anterior pituitary glands something about one of them not being connected to the hypothalamus yes Olivia great question when we look at steroid hormones steroid hormones are cholesterol based which means they're lipophilic lipophilic as you know means it loves fat now what is fatty they add a layer of our cells so if a steroid hormone wants to exert its effects on a cell it just moves straight into the cell and what it usually exerts its effects on are the DNA directly and it tells that DNA to transcribe and translate particular genes so what's the difference between amino acid protein and steroid hormones amino acid and protein hormones must exert their effects on receptors on the outside steroid hormones must exert their effects by binding to intra cellular receptors so there's a big difference when it comes to the receptors alright next point I want you to tell me of these three which one do you think has the shortest half-life so if one of these is released into our bloodstream which one do you think gets degraded first answer it for me pop it in the chat is that the amino acids is it the proteins or is it the steroids and if you make a statement I want you to have an educated guess as to why you think that's the one that has the shortest half-life what do we go so we've got steroids but from reef any justification any reasoning but it was at a guess or is there anything about it structure that makes you think steroids does anyone have any other guesses anyone want to what do we got we've got other proteins and amino acids the water soluble hormones correct amino acids and proteins are water soluble which means they like water they can mix in with it and think about what that means the blood is mostly water so usually these ones can just freely float through the bloodstream they don't need anything to carry them steroid hormones they don't like being in the bloodstream but there are hormones so they have to be in the bloodstream so they need carrier molecules they're non water-soluble so they need proteins they're not protein hormones just other proteins like albumin for example that piggyback the steroids because most cells within the body are lipid soluble that's true other Pro okay you know what that's really good justification reef it's not the case steroids actually last steroids and proteins so it'll last the longest between four minutes to one hundred and seventy minutes in the body and amino acids and short proteins last two to four minutes that's their half-life I shouldn't say that's how long they last in total that's how long it takes before half of that hormone is no longer exist so short amino acids and short proteins two to four minutes long proteins and steroids for 170 minutes and the one that lasts the longest is actually a protein called thyroid hormone which just really doesn't act like how the hormones thyroid hormone even though it's a protein based hormone exerts its effect inside the cell which is strange because no other protein-based hormones and it can last in the body from 0 to 6 days that's its half-life within the body all right now let's start talking about the hypothalamus and let's start talking about the anterior posterior pituitary glands and answer some of those questions all right first thing you need to know is that if I were to draw up to the brain where's the hypothalamus there's the brain there's the midbrain pons medulla spinal cord cerebellum all right this is the front of the brain so anterior this is the back of the brain posterior now the hypothalamus sits under the thalamus and the thalamus is around about here so the hypothalamus is around about here it sits on the medulla basically right the medulla is the top of the brainstem we've spoken about there so midbrain midbrain pons medulla the hypothalamus sits on the midbrain now underneath the hypothalamus that there's this little dangly thing and that's called the pituitary gland so what we're going to focus on is that area right now because the hypothalamus is an amazing structure it is what we call the master regulator of both the endocrine system and the autonomic nervous system all right so if I were to drop the hypothalamus break just quickly now I'm gonna draw up these two dangly things they are very phallic looking so I do apologize but that's just an exaggeration of what the hypothalamus and the pituitary gland looks like so we have the hypothalamus here hypo meaning below thalamus because that's where it sits and what the hypothalamus does is it receives a whole bunch of sensory input so if you see something or you feel something when you taste something or experience something whatever it may be there's gonna be signals coming into the hypothalamus it likes receiving those signals if something happens to an organ of your body signal gets sent to the hypothalamus something's happening in your brainstem signal goes to the hypothalamus right and it decides if it needs to do something and what it needs to do so the hypothalamus being the master regulator of the endocrine system usually exerts its effects via the pituitary gland and you can see that there's two lobes to the pituitary gland we've got the anterior pituitary gland or at least the anterior lobe and the posterior lobe of the pituitary gland that's the first thing second thing is that the hypothalamus will speak to either of these and tell them to release hormones into the bloodstream to have their effect depending on what signal the hypothalamus received all right what I want to first start off with is the anterior pituitary gland because it has the most hormones so it's worth probably most of the discussion the way that the hypothalamus speaks to the anterior pituitary gland is via a blood stream is actually a blood stream that connects the hypothalamus to the anterior pituitary gland and this blood stream is called the hypothesis portal system that's what this is called the high part so hypo Fasil so hypothesis portal system basically hypothalamus has hormones in it and it releases these hormones into the hypothesis system the hormones travel down until the hip anterior pituitary gland and then they release their hormones and into the body so when we talk about the hypothalamus and anterior pituitary gland we need to talk about what hormones our hypothalamus releases and what hormones the anterior pituitary gland releases let's first start with the hypothalamus now I'm going to number these hormones these numbers don't mean anything there's no order to these hormones it's just so we can compare which hormone up here regulates which hormone down here and again if you have any questions at any point just pop it in the chat and I'll try my best to answer it all right so the first hormone I want to talk about here first hormone I want to talk about is quarter cow tropen releasing hormone corticotropin-releasing hormone the next hormone I'm going to write down he's going to be thyrotropin-releasing hormone you're going to see a bit of a pattern here with a releasing hormone next one on we want to talk about is growth hormone releasing hormone and then the last one we need to talk about is gonadotropin-releasing hormone [Music] alright here's the thing all of the hormones in the hypothalamus have that releasing hormone at the end of it and it's because they're going to tell another hormone to be released right the term tropen which you constantly see what that means is tropen is a hormone that goes to another cell to tell that cell to release another hormone so there's actually many layers - how many hormones are released here the hypothalamus releases a hormone to tell the anterior pituitary gland to release a hormone to tell another tissue or structure to release a hormone and so the truck open is what demonstrates that there's still one more hormone to be released somewhere in the body okay so let's start off with corticotropin-releasing hormone let's just say this is the one that needs to be released and it's released from the hypothalamus and it travels down through this hypothesis or ttle system and it gets released at the anterior pituitary gland the hormone that the corticotropin-releasing hormone releases at the anterior pituitary gland is something called adrenocorticotropic hormone is this called cascades yeah cascading effects is simply that's great cascading effects is when one thing leads to another which leads to another which leads to another and in this case tropen czar cascading affects the hormones so basically endocrine system is so it's one of the most complex systems we're going to talk about because of as reef said it's cascading one hormone leads to a release of a dozen other hormones and this always happens and that's why it gets really difficult what about prolactin releasing hormone yes so I could put prolactin releasing hormone in there the reason why I haven't is because I didn't want to overburden you I didn't want to discuss let's put it in let's put it in prolactin releasing hormone because we will talk about it thanks thanks Maddy all right so let's start with the first one corticotropin-releasing hormone it's moved down the hypothesis system it's now in the anterior pituitary gland and it releases a particular hormone like I said it called adrenocorticotropic hormone so now let's write these ones up alright so one so the one that corresponds with number one here is number one here adrenocorticotropic hormone so I'll just write H adrenocorticotropic hormone sometimes you see it written as a CT h alright what does adrenal cortical chopper kamon do because this is now getting released from the anterior pituitary gland and it's going to have its effect somewhere so let's read the name Adreno what do you think Audrina I was referring to anyone Audrina Audrina what do you think it is I know there's a bit of a delay with the video but what do you think Audrina refers to adrenaline okay in part it does what does it dren illan get released from adrenal gland Thank You Olivia yes the adrenal gland so this is where ACTH has its effect what is the adrenal gland corticon is referring to the cortex of the adrenal gland which is the outer shell and entropic means that when it goes to the adrenal gland it's telling it to release another hormone does that make sense I hope it does ACTH is a hormone that goes to the adrenal gland specifically the cortex of the adrenal gland and because it's a tropic hormone it's going to tell the cortex of the adrenal gland to release another hormone hopefully that makes sense all right I want to draw the adrenal gland now answer one of those questions I think that Maddy had before about how does the adrenal gland what does it release how does it release it what does it do all right so I say tears bear lace now I'm just going to draw it up over here because we've got more room okay so adrenocorticotropic hormone has been released it travels to the adrenal gland now in actual fact I always say this and it simplifies it and students get confused it's traveling everywhere in the body right when that gets released from the anterior pituitary gland it's in the bloodstream that goes everywhere it just happens to be that the receptors specific for ACTH bind at the adrenal gland all right so we drop the kidney and the adrenal gland is the Hat that sits on the kidney so it's going here now if I were to drop the adrenal gland more specifically so you know it sits on the we've got two kidneys so we've got two adrenal glands right goes to both of them if I were to drop the adrenal gland you're gonna find that there's an outer shell and here which is called the cortex and the inner medulla adrenocorticotropic hormone stimulates most specifically the cortex what does it stimulate the cortex to release let's have a look it stimulates the cortex to release cortisol stimulates the cortex to release aldosterone and it stimulates the cortisol to release androgens and ro Jones all right these are three hormones that are released upon stimulation from ACTH which has come from the anterior pituitary gland and what do they all do actually there's two hormones that are released from the medulla which I should talk about right so well they're not necessarily released by ACTH they are to a small degree but not specifically there adrenaline and noradrenaline mainly adrenaline so cortisol what cortisol does is it's known as a glucocorticoid first of all all the hormones are released from the cortex of the adrenal gland our steroid hormones that's why they've got the uighurs IDN telling me that it's steroid corticoid all right glucocorticoid tells you that cortisol plays around with glucose levels and what cortisol does when it's released is it finds organs or structures of the body that have stored glucose and tell them to be released so glucose gets released into the bloodstream and blood glucose levels go up so that's what cortisol does it ends up boosting blood glucose levels it doesn't just do it by finding stored glucose and releasing into the blood it does it by finding non carbohydrate based energy sources so remember back in like week one week two we spoke about carbohydrates proteins and fats right carbohydrates are made up of glucose predominantly and that's an energy source fats are made up of fatty acids and triglycerides that's an energy source and then last one is going to be the proteins and amino acids right which can be an energy source cortisol can also tell proteins and fats to turn to glucose increase in blood glucose levels any questions just ask me and let's do aldosterone before you answer antigens aldosterone what that does is it travels to the kidneys and tells the kidneys to reabsorb sodium it increases sodium into the body what we call reabsorption I want you to answer this what is the consequence of if you go to the kidneys why would we want to go to kidneys and say don't pee out sodium bring it back into the body what's the consequence of that any idea if sodium gets reabsorbed into the body something else gets rear orbed into the body at the same time any idea what do you think I'll wait water perfect water water water are you guys are legends yes yes yes I love it Reef whatever sodium goes water follows think about a year salty chips you always want water wherever sodium goes water follows so aldosterone goes up the kidney says don't pee out that sodium throw it back into the blood therefore water goes back into the blood and our blood volume goes up which means our blood pressure goes up so aldosterone is released when we need blood pressure to increase increase blood pressure what do you think about this is there a relationship here because you need to think about there's there's all evolutionary mechanisms as to why things are released okay so you may look at this and you go okay something needs to trigger the hypothalamus to release corticotropin-releasing hormone which travels down the hypophyseal to release adrenocorticotropic hormone from the anterior pituitary gland that's released that travels to the cortex of the kidneys and it releases cortisol and aldosterone cortisol increases blood glucose levels aldosterone increases sodium reabsorption which basically increases blood pressure and at the same time there's a small release of adrenaline and noradrenaline coming out so what do you think was the original stimulus to tell the hypothalamus to release corticotropin-releasing hormone what told it to do this if the outcome is increased blood glucose increased blood pressure and a little bit of adrenaline noradrenaline what was the stimulus coming in what do you think what do you think what do you think what do you think any idea all right come on guess guess stress yes reef you know in brilliantly today it is stress sympathetic nervous system now shy with the sympathetic nervous system what you're going to find is the hypothalamus actually controls it so this so when I say to you the sympathetic nervous system gets stimulated from stress in actual fact stress stimulates the hypothalamus and that stimulates the sympathetic nervous system so at the same time that the hypothalamus releases these hormones it also stimulate the sympathetic nervous system coming down the thoracic lumbar system alright a dehydration neodym dehydration yes but not in this and I so it can in this scenario and it does through another mechanism and I'll talk about that a little bit in the future so firstly why do we want to increase blood glucose levels when we're stressed why don't we want to increase blood pressure when we're stressed alright when you get stressed and you activate the sympathetic nervous system you know it's fight or flight this system gets activated to keep you alive when you're stressed right so whatever happens like pupil dilation heart rate increases Airways open up peripheral blood vessels constrict URI shunt the blood to the muscles and so forth this happens as well now obviously the adrenaline noradrenaline help the sympathetic nervous system but also cortisol is released cortisol is known as the stress hormone it's released to increase blood glucose levels why because our nervous system like our brain only uses glucose for energy and if you're in a fight or flight scenario you need that sympathetic nervous system activated and you need it fed and you need it fed with glucose so blood glucose levels go up great thing is most tissues of the body need cells that take glucose and let it in your nervous system doesn't your brain doesn't need cells your brain doesn't need the insulin to tell glucose to come in right so there's that increase blood glucose why blood pressure well if your blood pressure is higher what does that then mean more tissues get oxygen and nutrients and we know that the blood vessels are constrictor in the periphery so that Bloods go into the muscles which means high blood pressure more blood going to those muscles more oxygen and nutrients so this is supporting that sympathetic effect of the sympathetic nervous system all right now the androgens is another one androgens such as dihydrate P and dosterone androgen and I should say in dosterone was it correct is part of basically the masculinization and it's basically what we call a secondary sex hormone and doesn't really relate to what we're talking about this trimester next trimester it will alright I think we're done with the first quarter coach Opik releasing corticotropin-releasing hormone let's move on to the next one which is thyrotropin-releasing hormone any questions at the moment have any questions let me know hopefully I'm going through this in a way that's it's understandable for you alright next one we're going to talk about is thyrotropin-releasing hormone so let's tick these off as we go through done that one now let's do a thorough trope and releasing hormone that gets released portal system here and it's going to tell the anterior pituitary gland to release a hormone what's the hormone here this hormone is called thyroid stimulating hormone sometimes just known as TS h that's what gets released sometimes you'll see it in your textbook written as thyrotropin now that's a thyrotropin and thyroid stimulating hormones the same thing so don't stress about that what does thyroid stimulating hormone do it goes to the thyroid and stimulates it right your thyroid is a butterfly-shaped gland hugging your trachea at the front like this and it produces thyroid hormone or to be more specifically thyroid hormones let's have a look so here's your thyroid hugging so your trachea would be like that behind it right there's a trachea and there's your thyroid gland so what happens is third stimulating hormone comes along and it binds to receptors right when a balance of these receptors it tells these cells or what I should say these groups are cells inside the thyroid to do something it actually tells them to pull these things in to make thyroid hormone what it pulls in are things like the amino acid tyrosine and iodine so thyroid stimulating hormone stimulates the thyroid gland specifically the thyroid stimulating hormone receptors and these cells of the thyroid go okay let's make thyroid hormone I'm gonna pull in tyrosine I'm gonna pull in iodine tyrosine hiding and it pulls them both in keeps pulling them in pulls them in and creates thyroid hormone and the two types of thyroid hormone is t3 and t4 right and then they get released into the body what t3 and t4 do is they're the thyroid hormone every time you hear thy erode or thyroid hormone this is what they do they its t3 t4 and they play a huge role in metabolism really important with metabolism so that means how you metabolize foods how you utilize energy which has vast effects on fat deposition has vast effects on temperature thermoregulation things like that all right now I want to talk about this for a second iodine chemical element in the body only place that's used is that the thyroid have you ever and I want you to answer this question for me have you ever seen at home that your table salt has iodine in it and it's called iodized salt yes or no have you seen that before have you seen iodized salt at home or maybe somewhere else yep so show seen anyone else seeing it yep reef Emily lovely perfect now why that salt doesn't normally have iodine in it salt doesn't have iodine associated with it but what we've done is what we call fortification we've taken salt and we've put iodine with it right and the reason why is to support the thyroid gland here's why the way that we normally get our iodine is the soil contains iodine plants grow in the soil and the plants take the iodine animals eat the plants and the animals get the iodine and we eat both the animals and the plants and then we get the iodine so ultimately our iodine levels reflect the iodine levels of the soil on the area that we live now some places are high in iodine most of Australia is pretty good there's places around the world with the iodine levels hello and so what happens is this or what can happen I should say is when these cells after thyroid stimulating hormones being released says make thyroid hormone a go okay they pull in tyrosine and iodine but there's no ID so they're just pulling tires in but they're not making thyroid hormone because we need iodine so it keeps doing it and it keeps pulling it in and pulling it in and what they're pulling in is simply just all this tyrosine and some other stuff and these groups are cells get bigger and fatter bigger and fatter bigger and fatter and what happens is the thought as they get bigger and bigger and bigger and bigger the thyroid itself gets bigger open up google and type this word in for me guitar GOI ter type that in I want you to have a look at what a goiter is what I've just explained is a goiter can somebody describe it once you've seen it I well yes okay good point GOI we all know that I'm not the best speller there is GOI tra try that try either one the it's going to pop up so what do you see I want you to describe it real basic aliy for me on the chat enlargement yeah does it look like the throat has like a balloon in it because that's pretty much what a good it looks like swelling yeah those on the episode of Seinfeld I don't remember that episode I'm gonna have to go back and watch swelling of the neck bulging neck enlargement of throat okay and that's simply because there's no iodine right so the thyroid gets bigger try to make thyroid hormone but it still doesn't so if it doesn't make thyroid hormone then they've basically got hypothyroidism so gooood r is the result of one type of hypothyroidism it's not the only type but it's one type which is iodine deficiency can result in hypothyroidism and can result in a goiter now if we look at hyperthyroidism where we create too much thyroid hormones if we create too much thyroid hormone let's draw this up and show how it works that's called hyper thyroidism so we've got the thyroid you've got these receptors you got TSH they need to come along and bind to the receptor and then that triggers these groups of cells to pull in the iodine and to pull in the tyrosine but here's a thing sometimes is that overactive under active ah so hypo is under active thyroid hyper is overactive thyroid so if somebody's hyperactive they've got heaps of energy if they're hypoactive they don't have any energy abnormal enlargement of your thyroid and glands so let's have a look at hyperthyroidism at least one of the most common causes so it's gonna hyper so this is overactive now this is the usual scenario TSH receptor iodine tyrosine and it spits out t3 and t4 which are the thyroid hormones but for some people they create all these antibodies right these are immune cells they create these antibodies that bind to that TSH receptor and if these antibodies bind to that TSH receptor they stimulate thyroid hormone to be produced and if thyroid hormones being produced it just keeps bumping it up so what this is is an autoimmune disease and it's called Graves disease so what I've got is what is the TSH stimulated by within the hypothalamus so the TSH is stimulated by the thyrotropin-releasing hormone it is released in bursts in waves so a lot of hormones have like these peaks and troughs peaks and troughs are out the day all right sometimes they go in accordance with the circadian rhythm sometimes hormones peak at night and drop during the day and some are vice versa thorough in hormone has the same similar rhythm it peaks and troughs peaks and troughs so there's going to be various stimuli from the body they're going to be metabolic based stimuli all right so things like well we need to take particular energy stores and utilize them or we need to store energy stores or it may have something to do with the thermogenic effect so temperature regulation there's a whole bunch of input that's why I didn't mention it because there's a whole bunch of metabolic based input that control the heart the film us to release start or open going down releasing that all right we're going to move on any questions let me know alright next one is growth hormone releasing hormone well we got it says referring to the toot workbook for the week the example for patient 3 I was getting a bit confused on what hormone was been over/under produced would have something to do with ADH can you type the question copy and paste the question for me because I can't remember it off the top of my head if you copy and paste the question we'll have a chat about it and we can go through what the answer may be in the meantime let's talk about growth hormone releasing hormone gets released from the hypothalamus travels down a hop off cell portal system and triggers the release of growth hormone unsurprisingly growth hormone releasing hormone triggers the release of growth hormone send up a threat so let's tick that off number 3 is growth hormone now this one's pretty easy to know what it does growth hormone stimulates growth of the body so growth hormone sometimes just written is gh what it does is it has anabolic so anabolic steroids people who take anabolic steroids get big right so anabolism is growth catabolism is breakdown and hormones play a role in this process so growth hormone is anabolic it's for growth makes you know makes sense growth hormone effects bone affects muscle affects the liver affects fatty tissue we just got out of post tissue and what it does is it tells bone to grow tells muscle to grow tells the liver to release glucose so it increases blood glucose tells fat tissue to release energy so it increases energy stores the reason why these two things happen is because in order to grow and develop you need energy available so the liver releases energy fat releases energy and your bone grows and your muscle growth now growth hormone is really important in early development right so it also plays a big role in differentiation what that means is early on when you are developing in order for one tissue to become like this and another tissue to become like this growth hormone helps that differentiation process so what we go sorryy here is a 54 year old male suffering frequent urination nausea constipation bone pain his blood calcium levels are measured to be top point five milligrams per deciliter when the normal is nine to ten is that all the information there is for that one Madi is there anymore is that all that was part of the part of the question if there's more to pop the rest in and what is what will the specific question asked is it say what hormone is affected I can't matter I wrote these right there's a little while ago so that's what growth hormone does let's Google something else right can you google acromegaly for me I probably spelled this one wrong too but that's okay typing acromegaly and describe what you see with acromegaly acromegaly is a issue with growth hormone so look that up then at the same time that's all the info okay thanks Manny I'll address that once we finish growth hormone and then I want you to type in gigantism Magali I got that right I CRO me yeah I got it right okay okay megali are big fingers that's definitely true what else do you see now compare Google gigantism versus acromegaly and have a look at how the people look differently how do what's their phenotype the way they present how is it different they're both issues with growth hormone but they look different so can anybody have a look and tell me what they think overgrowth definitely bones increase in size is there any difference between acromegaly and gigantism that you can see like visibly you don't have to read any of it but if you compare acromegaly versus what can you see you're very you're very right increases in bone and muscle size basically increases in growth height definitely individuals grow higher taller I should probably say height is increasing gigantism unlike acromegaly all right let's focus on that Thank You Shai that is perfect so height is increasing gigantism but not acromegaly here's the difference between the two both are problems with over activity of growth hormone both the problems with over activity growth hormone but gigantism occurs prepubescent acromegaly occurs post-pubescent what does that mean it means that when you're young your bones haven't yet not all of your bones have yet fused and not all of the cartilage because there's when you first when you're first born up until about two years of age your bones are basically like cartilage they're really rubbery bendy hard to break right but when you grow older you start hitting teenagers that cartilage turns to bone in hardens now if you have an overactive you overactivity of your growth hormone before all that happens you get uniform growth so your basic you basically look like anybody else you're just a lot taller and a lot bigger right uniform growth all aspects of your body grow in accordance with the right ratio of one another because those bones can all grow together the muscles can all grow together but if you have a growth hormone over activity after pubescence so after this cartilage just turned to bone and the bone is solidified only certain structures can grow and these structures include the forehead and the jaw and the fingers for example the when you're higher because the long bones won't let that happen does that make sense to everybody that's the difference between acromegaly and gigantism and their over activity of growth hormone how does this happen most common cause is a tumor in the pituitary gland now remember that tumors I cants dozen cancers are overactive cells so you've got overactive cells in the pituitary gland you can also Google the tallest man ever to live called a Robert Wadlow so Google Robert Wadlow again probably misspelled the name can anyone tell me what was the cause of his gigantism and I'm pretty sure what you're gonna find is that has something to do with the anterior pituitary gland you'll probably find that he had something like hyperplasia of the anterior pituitary gland which is simply it's not cancer it's just an overtly cell screw too much if they grew too much they release too much growth hormone and he got gigantism alright have a quick drink all right let's talk about gonadotropin-releasing hormone abnormally high level of human growth hormones perfect all right which is caused due to overactive cells here at the anterior pituitary gland alright check that one off going out of tropen releasing hormone that comes down and it releases gonadotropins so this hormone travels to our gonads to release more hormones alright an actual fact there's two gonadotropins so it says get out of trope ins because there's not just one hormone like we've spoken about for others this too so let's have a look we've gone out of tokens the two of them are follicle stimulating hormone and luteinizing hormone now this trimester do not stress about the gun out of tokens because next trimester when we do the reproductive systems they will be our focus all right but this trimester I'm going to give you a bit of a break I'll quickly tell you what they do though the gonads are going to be the testes and the ovaries right now both are our organs for sexual reproduction and FSH and LH work at both and what they actually do is this for the testes it plays a big role for sperm maturation and testosterone production for the ovaries it plays a big role in egg maturation which is basically the female version of sperm egg maturation or sperm is the male version of the egg and also plays an important role for ovulation so these are two really important roles that both FSH and LH play for the testes and FSH and LH play for the ovaries they're both going out of tokens and this happens in those respective gonads all right like I said that's a quick one because we're going to focus on that next trimester when we do the reproductive system all right next one last one is prolactin releasing hormone prolactin releasing hormone down the hypothesis' system releases prolactin and prolactin is all in the name Pro lactation Pro lactation lactation is the production of milk so simply put prolactin goes to the breast and promotes milk production not milk ejection but milk production that's basically what prolactin do it's pro lactation Pro meaning for lactation all right we are done with the anterior pituitary gland we now need to look at the posterior pituitary gland now there's not as many hormones there's only two so that makes it easier so we won't have to spend a huge amount of time on it any questions on the anterior so far can I get a thumbs up or a all good if everything's all good otherwise please ask me a question I need to know if you guys are understanding this I don't need to sit about it going oh my god this is the most horrendous thing I've ever heard what do we big smiley faces from Libya thank you showers on top of it thank you Thank You Rafe perfect all good all right I'm glad now you can watch this obviously any time it's going to be saved so I understand that you might go I don't get it now but you can watch it whenever you like you'll get it promise promise if I can get it you can get it I'm not the smartest person in the world all right Harbor Thelma posterior pituitary here's the thing it's not a blood stream that connects the two it's nervous tissue that connects the two I'm just going to draw one neuron just to highlight but there's obviously more it's a nervous tissue so anterior pituitary gland is connected to the hypothalamus through blood posterior pituitary glands connected to the hypothalamus through nervous tissue now this is what this means right it means that the hypothalamus is part of your brain so it's nervous tissue the posterior pituitary gland is nervous tissue so that means when you were growing and developing the posterior pituitary gland began with the hypothesis and stretched down but the anterior pituitary gland began separate to the hypothalamus and moved up to connect so that means that the posterior pituitary gland is what we call neuro endocrine it's both nervous and endocrine and the anterior pituitary gland is a true endocrine tissue so hopefully that makes sense what factors control the degree of cellular response to a hormone oh okay let's do that quickly before we move on what factors and then I can answer sorry then I can answer Maddie's question sorry Maddie so what factors control the degree of cellular response to hormone a couple of factors alright there's a receptor there's a hormone the question is what can happen to increase that hormone binding to that receptor and having a downstream effect a couple things how much hormone we have the more hormone we have the more likely it's going to bind and have its effect so quantity that's one next one is whether it fits in the receptor right so if you've got a hormone that square-shaped it's not going to fit in there but so this is specificity and then the last one is affinity how likely is it to remain bound to that receptor so you may have a hormone that jumps in and then jumps back out or you may have a hormone that jumps in and stays in there and again this has to do with the shape and the number and all that type of stuff so the three most important things that can affect how a hormone binds to receptor and have downstream effects is the quantity so how much hormone the specificity how specific it is to binding and the affinity how long it lasts in that receptor hopefully that answers your question denne all right let's go back to Maddie's quick question now Maddie's quick question I'm just gonna go back to my computer to read was about the workbook okay so 54 year-old male suffering from frequent urination nausea constipation and bone pain his blood calcium levels are measured to be 12 milligrams per deciliter which is above the normal 9 to 10 the question is which hormone is under or over produced what do people think what do you think the outcome there is blood calcium is high do you remember what we spoke about in the skeletal system there was a homeostatic control mechanism we spoke about in the skeletal system one that stimulated osteoclasts to break down bone one that worked with vitamin d one that increased the absorption of calcium parathyroid hormone correct that's what I would say so hopefully that helps alright now let's focus on posterior pituitary gland unless you had more questions Manny just let me know all right posterior pituitary gland here's the thing with the Tyrael hormones are made here and released and hormones are made here in released but for the posterior pituitary gland the hormones that are here are produced in the hypothalamus and travel down here to be stored so the two hormones are own they're produced here and they travel down and they are simply stored in the posterior pituitary gland so they don't produce okay thanks Maddie I hope I hope that helps produced in the hypothalamus and stored in the posterior pituitary these are the two hormones oxytocin and the second one antidiuretic hormone also known as ADH and sometimes known in the textbook as vaso pressin I only time I really read visa president is when I'm reading an American Journal or textbook so we refer to it as ADH don't here's what these two hormones do oxytocin alright actually I want you to tell me when you hear the word oxytocin what do you think what does oxytocin do in your mind you hear the word oxytocin and you start thinking what oh wait I'll see I know there's a little bit of a delay so to apologize you hear oxytocin and you think produce breast milk so prolactin produces it but oxytocin releases it ejects it oxytocin injects it labor as well love hate hormone oh you guys have covered it all so we've got uterine contraction by lovely Olivia said the same thing Emily says production breast milk McKenzie says releases breast milk lovely breast milk letdown yeah let downs a great way of explaining it and Maddie says love hey uh you guys have covered it this is a great tutorial group I wish we were doing this face to face it saddens me that we have to do it over the Internet all right oxytocin oxytocin is breast milk ejection and it ejects because smooth muscle are contracting so oxytocin plays a real big role on smooth muscle contraction and also uterine contractions I was on the ABC last night talking about the uterus the uterus is obviously an amazing strength it starts has been 50 grams and at the end of pregnancy it weighs a kilo starts at 50 grams finishes alone a kilo and most of it is muscle and it's relatively strong that muscle contracting to push that bub out and the last thing is said love-hate hormone there which is one way of explaining I'm just going to say it solidifies relationships and let me tell you why because you're right by saying love hate it does the simplifier but let's talk about that for a sec right so breast milk rejection that's easy or letdown ejection letdown whichever term you want to use that's fine you know contractions that's cool get Bobby out solidifies relationship so we all think of oxytocin release our makes us happy all right when a mother is breastfeeding her bub the milks being ejected because oxytocin is being released right at the same time mum feels good about doing this she feels good because of the oxytocin and dopamine but oxytocin so what happens is when you feel good about doing something you want to keep doing that thing now when we look at evolution this is a great idea evolution has made it so that when you feed your baby keeping it alive you feel good about it and you do it more maybe survives and what that means is baby can reproduce itself and so forth so this is a great evolutionary mechanism but what the found is it's not just this feel-good molecule the found oxytocin levels boost right up when they look at the oxytocin levels of warring tribe members so they hate these other individuals and their oxytocin is through the roof so what it does is it gets released any time some relationship has been built is there any disease related to oxytocin hormone oh it's a good question look I don't know of any but that doesn't mean there isn't one I can't think of one the the body is strange and the body does things and there's always an over release and under release of things if you can abnormal amount answer you can have abnormal amounts I don't know what the clinical manifestation of that would be if anyone can find out and type it brilliant I love learning that so I actually haven't heard of and hyper or hypo oxytocin release antidiuretic or man and did I already call it so die die you're a diaeresis not diarrhea that's different what does diuresis mean can somebody type in any idea what diuresis means if you can tell me diuresis well you're acting urination perfect regulates water and the blood perfect alright I like to think of this so diuresis urination increase excretion of urine increase of urine low oxytocin levels have been linked to autism interesting didn't know that things you learn so die so when I think die erases I think peeing right anti diuresis means anti pain so this hormone gets released and it doesn't stop you from pee but what it does is I guess to the kidneys and tells the kidneys hey don't pee out that water throw it back in the body so what it does is it increases water reabsorption now if you increase water absorb water absorption back into the body he doses the blood right which increases blood volume and also increases blood pressure now here's the thing in what scenario so ignore this stuff at the moment in what scenario would you want to reabsorb water someone said it why maybe like 35 minutes ago in what scenario would you want to reabsorb water come on what's going to happen what do you think you want to reabsorb water in times of dehydration thank you lovely I think you're the one that said it earlier to or it could have been shy so when you're dehydrated this is a stimulus that hypothalamus does a couple of things hypothalamus all of a sudden you go I'm thirsty you know that thought always comes out of nowhere you I'm thirsty can you take a drink that's coming from your hypothalamus I'm thirsty but it also sends the signal down to release ADH which go see your kidneys and pulls the water back in now here's how this so the hypothalamus can sense dehydration the question is how does it sense dehydration that seems to be a strange thing like this if you've got a container that's filled with water and you put a whole bunch of salt in it right whole bunch of salt or sodium and you measure the concentration of that salt in the water and let's just make up a number let's just say the concentration of that salt in the water is 300 right whatever that means but that's what it is now let's say I dehydrate that bucket I dehydrate it that means I only take out water so I take out this Warren and I take out half of it answer me this what happens to the concentration inside of that bucket is it become has it become more concentrated or less concentrated what do you think high concentration yeah it becomes more concentrated so that means it goes from 300 maybe to 320 now this change in concentration of fluid is called osmolarity you've heard of osmosis osmosis is the movement of water that's determined by concentration changes so when concentration changes occur it's called osmolarity if we go from 300 to 320 that's an increase in osmolarity and this is what the hypothalamus measures it measures changes in osmolarity for example it basically says how much sodium is present in the fluid surrounding me that's what it does and if it's too high it releases antidiuretic Alma but you can also release ADH when your blood pressure's low too and that's the same with aldosterone right because that increases blood pressure to both aldosterone and ADH work together to increase blood volume and blood pressure and both of these happen when blood volume is low I don't really understand what it means in the lecture notes by released in response to increased osmotic pressure concentration in the blood it's exactly that so all that's saying is okay so the hypothalamus is just a collection of stels right so let's just say here's a collection of cells and that's the hypothalamus cells are surrounded by liquid right so they've got liquid inside of them they've got liquid surrounding them so outside the cell is extracellular fluid so you've got all this fluid surrounding this cell now normally the concentration of this fluid outside is around about 300 and the units that we measure is called milli osmoles don't stress about that but it's 300 just like the scenario with the container if I were to take just the water out so you do a whole bunch of exercise and you sweat so much you lose all this water it becomes more concentrated out here and that 300 turns to maybe 320 millions moles it becomes more concentrated these cells can measure how much sodium is here compared to the water it measures that concentration change which met which means it measures the ozone modoch difference the osmotic so think about it right if it becomes more concentrated outside the cell water from inside the cell wants to be pulled out does that make sense remember remember tonicity right if you've got a container with a membrane and you've got water but you've got heaps of stuff dissolved on that side of the membrane what happens is water wants to get pulled across if that's outside the cell and that's inside the cell water wants to get pulled out of the cell same thing happens here when you get dehydrated what happens is the water from inside the cell wants to be pulled out the hypothalamus can feel this it feels the water leaving it sells and that's measuring osmotic pressure changes Olivia does that make sense if not I'll try and figure out another way to explain it but I hope that makes sense that's how the hypothalamus works when it measures that change that shift in fluid that's measuring osmotic pressure changes and that triggers ADH to be released is that okay sorta that's okay you said oh yeah at the beginning I take that as a win because it's not a simple concept so we'll keep going through it alright it's time we've done this for too long unfortunately I couldn't go through the pancreas and insulin stuff but I'll release a little video for you to watch in regards to that all go for five minutes but apart from that thanks everyone I hope that was good and enjoyable hope it wasn't too boring I know it's a lot my throat's killing me yeah I see you also in do your online quiz it's due on Friday and it's all the nervous system all right thanks team

Channel: Dr Matt & Dr Mike

Views: 41,004

Keywords: endocrine, system, anterior, pituitary, hypothalamus, hormones, thyroid, adrenal, pancreas, insulin, blood, glucose, gland, axis, tropic, anatomy, physiology, nursing, medicine

Id: fwLUURlzhIQ

Length: 68min 15sec (4095 seconds)

Published: Mon May 25 2020