hi it's mr. Andersen and welcome to the endocrine system podcast if you look way up there at that guy his name is Robert Wadlow and that guy I have no idea what his name is because he's not Robert Wadlow Robert Wadlow is the tallest man that we have in modern day he was something like eight feet 11 and a half inches at the time of his death and he was that tall because he was a pituitary giant in other words he had a tumor we now know that was pushing on his pituitary it was making it produce a hormone called growth hormone which made him get as tall as he eventually was and so that wasn't normal it does put pressure and he died fairly young just mostly I think do circulation problems he started to get blood clots and so basically it talks a little bit about the endocrine system when I'm talking about the endocrine system the other system that's really important to talk about is called the nervous system so the nervous system remember is basically going to be made up of neurons so you have all these dendrites that come in to the cell body so the cell body looks like this and then you have an axon that comes way down here and then you're going to have another neuron down here that's connected with a bunch of dendrites to a cell body and it's going to move here now this distance right here excuse me the separation between the two is called a synapse a synapse is going to be a gap between neuron one and neuron two now why is the synapse important well we get control over the chemicals that we send but this podcast isn't about the nervous system and the reason why is that nerves just travel in one direction from this neuron to another one neuron to another neuron they just go in one direction and so my analogy is it's like Gmail when you send an email from one person to another person where they send it from one person to another person that's like the nervous system you're sending a message from one person with a clear destination and that's the nervous system it goes really fast and it's going to target a specific cell and so when do we use the nervous system when we have to do something really quick so if somebody were to throw something at me and I were to dodge it that would be my nervous system that is acting so the endocrine system is more like Facebook if I were to post to my facebook status update that I am working on a cell communication podcast by myself ironic and I just put it out there there's going to be a delay there's going to be time before other people look at it and dislike it or like it or respond to it and so that's going to be more like the endocrine system I'm sending it out to everybody and whoever wants to respond to it can and so basically keep that in the back of your mind what are some terms that you should understand first of all anything that is going to send out these messages in the endocrine system is called a gland and we'll go over ten important glands the chemical that they send out is called a hormone and then it's going to target cells or not it may target certain cells or it may not target other cells and so we could send for example follicular stimulating hormone from the pituitary that's only going to affect on the ovaries and the testes but if we send up growth hormone that's going to affect all the cells in your body so what are those hormones do they simply diffuse throughout your body they're going to spread throughout your body and so they are going to bump into cells or not they're going to spread throughout your whole body and that's why if you've ever felt like adrenaline you almost get in a car accident you just feel like almost something coursing through your body that's going to be your endocrine system now when they find cells one of two things can happen if they are a water soluble hormone example could be epinephrine or adrenaline they're water soluble basically what they're going to do is they're going to dock with a protein on the surface of their cell since they're water soluble they can't gain entry to the cell and so usually what they'll do is they'll set up some kind of a signal transduction pathway just have some kind of an action out here or have another action inside the nucleus where we could make certain specific genes or certain proteins transcribe certain genes but that would be water soluble we also have what are called lipid soluble so testosterone is an example of that basically since its lipid soluble it's going to move right through that the lipid bilayer that is the cell membrane and it also can target with a cell and move right into the nucleus because again there's going to be a lipid bilayer here as well and so lipid soluble hormones are going to move all the way into the cell water soluble are just going to dock with a receptor protein on the surface and so here's our endocrine system so endocrine some is not as tightly linked together like the circulatory system but again it doesn't have to be because it's sending hormones throughout the whole body and so basically we've got glands going all the way up to the top to the from the pineal gland all the way down to the ovaries and the testes in the bottom and so basically what I want to do is I've chosen 10 glands in the endocrine system 10 that I think are pretty important there are more than that and then I've just chosen one hormone for each of these and we're going to talk about that so let's talk at start at the top first one is going to be the pineal gland pineal gland is going to be right here basically what the pineal gland is going to secrete is a chemical called melatonin it does that only when it's nighttime and so if your eyes are open during the day you're not going to be secreting melatonin but when you close your eyes at night it's going to start giving off melatonin and so basically what that does is it allows our brain to tell what time of the day it is and it also allows us to figure out what season it is and so basically we can set up what's called our circadian rhythms so it's basically our internal clock and it's pineal gland doing that next let's move down here this part of our brain is actually called the hypothalamus and the hypothalamus is kind of the connection between the brain and the endocrine system and so it can secrete hormones as well but we're going to say it's influencing the pituitary we're going to talk about what the pituitary does pituitary basically if we were to look at it like this the pituitary let me blow that up a little bit so the pituitary is going to go down like this and so it's going to have two lobes to it it's going to have the anterior anterior means towards the front or towards the head and then it's going to have the posterior posterior is going to be towards your rear end is the best way to think about it and so what's the anterior pituitary give off well it gives off growth hormone it gives off a number of other things it gives off endorphins it gives up follicular stimulating gives up all these different hormones but one that we're going to talk about is growth hormone what's growth hormone going to do growth hormone again is going to flow throughout the rest of your body can do that in the circulatory system or throughout the interstitial fluid and basically it's going to cause the cells to grow so they're going to get bigger if we talk about the next one anterior or excuse me posterior pituitary it gives off oxytocin but the one important we're going to talk about is antidiuretic hormone or ADH and so anti diuretic hormone well you know what diarrhea is and so what is antidiuretic antidiuretic is going to be a hormone that holds on to fluids inside our body where is that going to go it's going to go to our kidney because our kidneys and control of osmoregulation what's the next one next one as we work our way down is going to be the thyroid so we're going to move all the way down here this would be the thyroid gland sits right in here basically it does two things that are important it gives off what are called t3 and t4 those hormones and the numbers relate to the number of I and our excuse me iodine atoms that are found within it and so basically you've maybe heard of a goiter when you get an inflamed thyroid basically what our thyroid does is it regulates metabolism and so it's going to give off these two chemicals t3 and t4 and that's going to speed up metabolism inside our body and so if you have a hyperactive thyroid that you have high metabolism if you have a in active thyroid then you're going to have really slow metabolism and so basically it's control of that and the other thing that it does is it secretes something called calcitonin and again endocrine systems are really important in feedback loops and so the calcium that we have in our blood the level that we have is super important especially nerves and in muscle firing if we don't have the correct amount of blood calcium we're going to die and so basically what the thyroid does is it when you secrete the thyroid it's going to lower the calcium well where's the calcium going to go it's going to go back into the we're going to excrete some through the kidneys but it's going to go back into the bones and so there's another hormone that kind of goes with that so this looks like a butterfly but there are going to be these tiny little hormones in here called the parathyroid they sit right within the thyroid and they're going to secrete something called parathyroid hormone what does that do well if the blood calcium level goes too low it's going to raise the blood calcium and so these two the thyroid and the parathyroid are going to work together to basically keep the blood calcium level correct it's the same way that insulin and glucagon work in the pancreas speaking of which let's go to the next one and so the pancreas is kind of hard to see in this diagram but the pancreas is going to sit right here it's again behind the stomach and it's going to empty right here into the duodenum so it's going to empty enzymes in here but it's also on its surface it's got beta and alpha cells that are going to secrete insulin and glucagon insulin is going to be secreted if we ever need to lower the blood sugar and glucagon if we ever need to raise the blood sugar so basically what a Lintz insulin does is when it's secreted it allows our cells to take in that blood sugar that glucose and glucagon when we release that it's going to release more of that insulin from glycogen that found right here in the liver so that's the pancreas on the top of our kidneys so these would be our kidneys right here on the top of them we have our adrenal glands the adrenal glands have two parts to it the adrenal cortex is going to be on the outside the adrenal cortex is basically what it does is secretes glucocorticoids and so if you ever have an injury and you get huge amount of inflammation in it they secrete anti-inflammatories and so if you've ever taken an anti-inflammatory example be like Advil basically the glucocorticoids are going to do the same thing they don't need to act right away and so these are actually connected by hormones to the pituitary so the message can come from the brain we have an injury down to the pituitary and eventually to the adrenal cortex but that's not what you're familiar with in the adrenal gland you're familiar with adrenaline and so there's a nervous connection from the brain all the way down here to the center of the adrenal gland that's called the adrenal medulla basically what is it's going to have it do it's going to secrete epinephrine epinephrine is adrenaline it's going to go throughout your body and it's going to trigger that fight-or-flight response and so again if you almost get in a car accident nervous system is going to allow you to kind of not get in that car accident but after that you're going to feel this adrenaline coursing through your body your metabolism is going to speed up you're going to suppress like your digestive system you're going to become more alert and that's all as a result of the adrenal medulla okay next we've got down at the bottom we just have the sex hormones in the end the sex glands we've got the ovaries and so this would be in female and then the testes if we're talking about males ovaries are going to give off estrogen testes are going to give off testosterone among other things but basically those are responsible for your female and male sex characteristics now when you go through puberty before you go through puberty they're not really cranking out a lot of estrogen and testosterone but once you go through puberty they're getting the signal from the pituitary gland that says now it's time to make these sex hormones and then we get those secondary sex characteristics okay so how'd you do can you remember the ten glands can you remember the hormones that they secreted and what they did well let's try okay so as we go through this testes where they found can be found right down here what do they do they give off testosterone that's right what about the ovaries where they found ovaries are going to be found right here what do they give off estrogen that's right sorry for the awkward pause it's like Dora the Explorer next we've got the adrenal medulla where's that found yeah that's the green what do they give off that's right epinephrine let's go to the next one adrenal cortex where's that it's going to be the yellow part remember around the adrenal gland what do they give off I bet you've forgotten this those are glucocorticoids they're going to be anti-inflammatories what's next that's going to be the pancreas pancreas is found right here what's it give off insulin glucagon those regulate blood sugar let's go to the next one where's the parathyroid that's right that's going to be within the thyroid they used to actually when people get goiters they cut parts of the thyroid out and the person would immediately die because they didn't understand what the parathyroid did so parathyroid is going to be inside here what's it going to secrete parathyroid hormone that's right and that's going to raise blood calcium right above that we've got the thyroid thyroid is going to give off two things can you remember those it's going to give off calcitonin that's going to lower blood calcium and it's also going to give off t3 and t4 okay let's go to the next one posterior pituitary so that's going to be way up here what does that give off and I diuretic hormone that's right that's going to keep our body holding on to the water retaining water and then we've got the anterior pituitary so in the front that gives us a lot of things do you remember what it gives off thinking back to Robert Wadlow right gives off growth hormone that's going to cause our cells to grow and finally we've got the pineal gland pineal gland close your eyes you're going to start secreting melatonin that's right and that allows us to sync up our circadian rhythms so these are their top 10 glands top 10 hormones and I hope that's all helpful