so this is one of the harder systems this semester just because of all of the hormone names so we're about to have a good time but at least it's a pretty short chapter so that's good we always start every chapter with what's the point so the point of this one is it's really all about hormones so that's the key to the endocrinologist cells working together that secrete hormones so these guys are located throughout the body they also are in other body systems so this is why we don't do an endocrinologist look at the endocrinologist what is the important of this system well I would argue this is like the second most important system in our body behind the nervous system because this guy is really about communication and so our body is made of lots and lots of glands and so the key with the endocrine system is these are ductless glands so a duct is a tube so like your salivary glands which we'll eventually see when we get to the digestive anatomy that's a gland that's in your cheek that releases the saliva into a little tube that squirts into your mouth well these are glands that don't have tubes so they're just directly secreting into the bloodstream so this is pretty powerful stuff right because blood is everywhere in your body so you dump something into the bloodstream and it has full body distribution in less than a minute so that's a pretty powerful thing it's kind of like if I was gonna kill a bunch of people which I would never do okay ever ever but if I was gonna kill a bunch of people I would poison the water supply which I think's been in like some movie because it's like that's the most efficient way to do it right because it's gonna spread to everybody's house and everybody drinks water done so that's kind of the danger of hormones these are very powerful things because once they're dumped into the bloodstream again in under a minute they're pretty much everywhere in the body having in effect so these are just a small list of what's affected by hormones blood sugar blood sugar balance is crucial as is calcium balance and water balance so these three are probably the three most important for homeostasis responding to stress so stress sucks but it's there to kind of help you survive whatever you're going through at the time reproduction sex and baby's growth so whether that's growing in height or growing muscle and then labor contractions I don't have kids cuz I don't like them but I imagine that when that Labour process begins you kind of want it to be done like as soon as possible physical characteristics we know naked boys look different than naked girls because of hormones so this is just like a little random list of all of the different things that hormones do and that's kind of the craziness of this chapter is it just affects so many other parts of your body so the study of these glands and the study of hormones in general is called endocrinology so again ductless glands glands that don't have tubes and it's all about hormones so it goes back to homeostasis every chapter goes back to homeostasis except for reproduction you don't have to have sex to stay alive you don't have to have babies to stay alive but reproductive hormones are part of the endocrine system so having estrogen and testosterone Sturt certainly affects homeostasis but the last chapter we talk about this semester actually having the babies doesn't otherwise that is the goal of every organ system is to keep you on that straight and narrow path maintaining that constant internal environment and so the endocrinologist came off special senses and how the nerve impulse for vision and hearing I mean nerves are freaking fast right 30 meters per second well endocrine systems a little bit slower because the hormone has to be dumped into the blood and then it has to get where it's getting but I would argue it's still really really fast but it's not as fast as nerves but if you've ever had a deer run out in front of you when you're driving you have felt how quick the adrenaline rushes over you right so you have understood how quick the endocrine system is so if we understand the endocrine system it helps us understand all of the other organ systems as they're working together so the beginning of this chapter is just some general stuff and then we'll be getting into some specific examples of certain types of hormones so definition of a hormone it's a chemical that is secreted like I said from either one cell or from a whole bunch of cells from a gland it's going to either act locally or it's gonna travel in the blood and go anywhere in the body that it wants to and so that's kind of the the genius of the endocrine system so hormones are gonna act on target cells so if I'm dumping a whole bunch of hormones in the blood how do the tissues know which ones they should respond to I mean testosterone doesn't affect every cell in your body adrenaline doesn't affect every cell in your body insulin doesn't affect every cell in your body so how does it know so if you look at this picture that I stole from the internet I think it really illustrates this you could see the little secreting cell how he's secreting his hormones the little blue circles they're getting dumped into the bloodstream and then the target cells the cells that are affected have the right receptors so it's like you may have 10 keys but only one opens your house so only the target cells with the quote-unquote locks are gonna respond to the right keys to the right hormones so this is how your body sorts it out because otherwise you'd have you know these you know 30 more hormones floating around in any given second and all your tissues would be affected another thing about hormones besides traveling in the blood which is a crucial thing which is why I made it all big and bold they're they're very very strong they're very very potent it just takes a little bit a little drop a little smidge a little dollop you don't need a ton of this so it's a very very very powerful thing so just a little bit of hormones will have a dramatic effect on the body so this is the picture describing that transport mechanism from your textbook so hormones travel in the blood that's what makes a hormone hormone so on the left here we have a gland that's secreting the hormone and then on the right side we have the target cells they have the right receptors so cells that have the right receptors you can see they're letting the green dots in they're letting the the hormone in but the cells that don't don't so this is how your body sorts all out all this chaos how long does a hormone last we can't really say like there's no general rule because it just completely depends on the hormone so it varies all over the place some hormones are done in seconds like an adrenaline rush once that deer has Modi mosey down down the road you kind of get back to a normal state right your heart rate goes back to normal your breathing rate goes back to normal so we feel that intensity for just a few seconds or you could have hormones like the sex hormones like estrogen and progesterone that drive the menstrual cycle good times that lasts for days you can alter a hormone by either in activating or excreting the hormone so basically you can stop the hormone or start the hormone so it's like a red light green light kind of thing the body has to control these hormones these are powerful things hormones are almost like drugs and if you don't control them it's very dangerous and so we have to control these hormones by either saying go for it or nope so red light green light before we get to the specific types of hormones and what they do I want you to know some again general background stuff like what hormones are but also the two types of hormones so all hormones can be divided into two different classes one we have the steroid hormones these are lipid based and if you remember lipids from A&P one lipid is just a nice word for fat so I googled butter and for some reason there were ants on the butter and I didn't notice it and so now they're just in my powerpoint and I'm kind of fond of them so fat based hormones versus the non steroid hormones which are protein based so these are the kind of the two categories of hormones so I need you to know the two Catterick categories of hormones and how they work okay so if we're looking at the lipid based steroid hormones these guys they can pass right through the cell membrane if you remember from A&P one this L membrane is nonpolar fat is nonpolar lipids or nonpolar water however is polar so if you're on Polar's team you hang with polar things if you're on non Polar's team you hang with nonpolar things oil and water don't mix as they say water and fat hate each other so if you're on lipids team if you're a steroid hormone when you come up to the cell membrane the cell membrane says come on in because you're on the same team so this is going to affect how they work the fact that these steroid hormones can pass right through the cell membrane so here's some examples you do not have to know which hormones are steroid based and which are non steroid that's not the point of this okay so what you need to know about lipid soluble steroid hormones is they can pass through the cell membrane but I wanted to include some examples that we'll be talking about so all three sex hormones estrogen progesterone and testosterone are all fat based cortisol which is the stress hormone aldosterone which affects water balance and try to a Cyrenian and thyroxine both come from your thyroid gland and they affect metabolism so all of these are examples of fat based hormones so fat based hormones are just as important as the nonfat based hormones so how do these guys work these guys work the lipid steroid hormones work by what's called direct gene activation so if you remember from a mp1 DNA to RNA to proteins this is the number one idea of biology DNA makes RNA RNA makes proteins DNA to RNA to proteins DNA to RNA to proteins so these proteins are what we call Gene's so all a gene is is a stretch of DNA that codes for a protein so you're activating the DNA directly that's what direct gene activation is you're able to get to the DNA directly so this sounds more complicated than it has to be so inside the nucleus is where the DNA is well if I am a fatty fat hormone I'm gonna come up to the cell membrane the cell membrane is gonna say come on in then I'm gonna come up to the nuclear membrane which is also a phospholipid bilayer if you remember that and the nuclear membrane is gonna let me in and I can get to the DNA so the point is because I am fat based the fat cell membrane and nuclear membrane is gonna let me get to the DNA so when I get to the DNA I'm gonna be able to read it and make RNA specifically messenger RNA which is what that little M is and then I'm gonna make proteins so the take-home message of this is steroid hormones cause certain proteins to be made because we can directly read the DNA we can do direct gene activation so this is just a flowchart so the steroid hormone arrives at the tissue cell it's able to diffuse in if you don't remember diffusion we're gonna be talking about diffusion practically in every chapter this semester diffusion is the movement of molecules from high to low concentration like when you breathe the carbon dioxide is crowded inside your body it wants to escape if you're number 10 in line at Walmart and they open a new checkout you're gonna haul ass and knock over old ladies and moveright the Walmart people don't have to make you move that's the joy of diffusion it doesn't require any energy any ATP for things to diffuse into ourselves they want to go in so this is a beautiful thing so the steroid hormone the fatty fat hormone arrives at the cell membrane and it's able to just come on in so it binds with the receptor and reads the DNA DNA RNA proteins so this picture looks really complicated and I know how you are I used to be you I would never look at stuff like this it was like oh it's so hard but this really does explain it well so if you look there on the right side we've got the cute little steroid hormone the little yellow guy and he's gonna make it through that first membrane the cell membrane and then the second membrane which is the nuclear membrane he's gonna bind with those molecular chaperones which we don't care about that's just some biochemistry so he's just binding with a receptor and you could see he's able to read the DNA directly when he reads the DNA directly he makes RNA which is called transcription DNA - RNA is transcription then the RNA leaves the nucleus and goes out and finds a ribosome which is that little weird brownish-red structure and the ribosome translates it into a protein so we call that translation so the steroid hormone is able to get to the DNA the DNA is read into RNA the RNA is read into a protein so the result of the fatty fat steroid hormones our new proteins are made so what can these proteins do some of these proteins will become enzymes if you don't remember from A&P one we're gonna talk a lot about enzymes this semester enzymes speed up chemical reactions sometimes 10 trillion times so I can't conceive of what 10 trillion is I mean 10 trillion is a number that doesn't even make any sense to me but I know that if my body or my car slowed down 10 trillion times I'm not getting anywhere so I mean this is really affecting your body's chemistry some of these proteins will alter membrane transport if you remember the cell structures from A&P one the phospholipid bilayer cell membranes are mostly fat but they have those big protein doors so some of these proteins will become doors so that's gonna affect how things get transported in and out of cells these proteins may activate or inhibit existing enzymes meaning it may say go go go or inhibit means no no no other enzymes so again causing something to happen or stopping something from happen happening another key point to the fatty fat steroid hormones is the cellular response is proportional to the number of hormone receptor complexes formed so that sounds really difficult but what that means is how much hormone you're making is going to result in how much protein you get so it's kind of like if you're knitting a scarf if you're one person knitting a scarf there's only so many scarfs per day or per week that you can crank out right it's proportional to the work then we have the peptide hormones peptide bonds are protein bonds so these are the the non-steroid protein hormones you do not need to tell the difference between the big ones and the little ones but they're their size always matters that size really matters with proteins and so they kind of split it your textbook splits it into small amino acid chains and large ones we just care about protein hormones so what are the characteristics of protein well proteins water-soluble right if you drink a protein shake it dissolves in the water because otherwise you'd end up with a lot of chunk if Funky's in the bottom of your glass and that's disgusting so oil and water don't mix right so the lipid stir the lipid hormones the steroid hormones do not mix with water these guys do so these guys are water-soluble so because of that they can't just come into the cell the cell membrane is going to say because the cell membrane is made of fat he is gonna say hell no h2o lover you can't come in so these guys are pretty small there's also larger protein hormones as we'll see on the next slide so a couple of examples pirate rope and releasing hormone which affects your thyroid gland and vasopressin which affects blood pressure again you do not have to know that vasopressin is a peptide or protein non steroid hormone we just need to know how the steroid hormone works and how the non steroid hormones work but because proteins can be ginormous they call these guys the polypeptide poly just meaning many again they function exactly the same so we don't care so these guys again water-soluble because their proteins which means they come up to the cell membrane and the cell membrane says hell no h2o lover you can't come in so these guys are pretty big so these guys are catecholamines which is gonna affect like ion balances in your body and insulin which most people know affects your sugar the difference in how these hormones work is based on where the receptors like where a lock is for a key to fit is located so a lot of locks are on the outside of the door right but some locks you have on the inside of your house so the same thing with cells some receptors are on the inside of the cells some receptors are on the outside of the cells so the receptors that are inside the cell is the direct activation that we just saw with the steroid fatty fat hormones that steroid if you remember the picture that little yellow steroid was able to dock with that receptor inside the nucleus because both the cell membrane and the nuclear membrane led him in because he was on their team so we had direct gene activation we were able to directly use the DNA now the protein once the receptors are on the outside of the cell membrane so we can't directly get to the DNA a protein hormone will never be able to get to the DNA he's never going to be able to get through the cell membrane in the nuclear membrane because he's not on fats team so we call this indirect activation this is going to use a second chemical messenger so these are our protein non steroid hormones so we're using this second messenger so the protein hormone arrives at the cell he's not going to be allowed in so the receptors on the outside of a cell just like having a lock on the outside of your door you don't actually come into the house to unlock the door this activates an enzyme which is called a dual innate cyclase you do not need to know that but this causes cyclic AMP or C amp to be formed in the cell C amp is the second messenger and so then C amp accomplishes the desired action of the hormone so if you've ever heard the phrase don't shoot the messenger it's like the messengers just you know passing on the information right C amp is just passing on the information this picture here which is a little bit complicated but we don't need all these details what we need to see is you see the little hormone there the little red triangle he's bonding with the receptor he's a protein based hormone so he can't come through the fatty fat cell membrane so when he docks it's just like putting your key in a lock it changes the lock this activates a Talon 8 cyclase again we don't care but that guy is making C AB so you can see down below like he's he's causing cm to be to be made C Anthon is gonna take inactive protein kinases and activate them so C amp the prout or the hormone sorry the hormone the protein hormone is wanting to activate these protein kinases that's his job but he can't get into the cell to do it directly so he needs cm to do it for him so that's why we call CA up the second messenger this picture here is just illustrating the same thing the hormone is docking passing the information on to see amp and then see amp takes that inactive protein kinase and activates it so an example I think of with this is occasionally a cop will come to my classroom door and like they all they always hover outside the classroom door like really awkwardly like they don't want to interrupt class but it's like everyone can kind of see them through the little glass window but they don't want to come in so I always go over so I'm like the purple receptor the cop is the hormone and he hands me like a note for one of the students in the class so then I passed the note on so then I become si amp which is kind of ironic because my initials are a MP Amanda Murray posh burger so I'm accomplishing the desired the desired reaction the cop wants to let somebody know something happened or that they're in trouble I passed the note to the student and then the student usually gets up and goes and talks to the cop so the cop didn't directly deliver the bad news I had to so this hormone doesn't directly activate protein kinase the CM does so that's why again it's a second messenger we have to rely on C amp to do this because this hormone cannot get through the cell membrane so these proteins are called kindnesses ASE means it's an enzyme so these guys will either activate or inhibit other enzymes so remember enzymes are speeding up chemical reactions ten trillion times so stopping or starting an enzyme is gonna have a very powerful effect on the cell some of these kinase a--'s will change the membrane permeability permeability just means that some things can be let in some things can be kept out so closing a door is just as powerful as opening a door so some of these protein kinase kinase 'iz will change what's led into the cell and what's let out some of these guys will fire up protein synthesis which is just the making of proteins your whole body is protein based not just hormones and so this is a very powerful thing stimulate or inhibit metabolic pathways metabolic pathways are just chemical reactions again starting or stopping red light and green light both of those are very powerful things starting a chemical process in your body is just as important to stopping it so a key point with this is the fat hormones had a proportional response one person knitting a scarf you're only gonna get so many scarves right these guys work completely different than that because these guys are enzymes enzymes can be used over and over and over and over and over again so one hormone molecule can cause a million chemical reactions so this is what we call an amplification effect not a proportional effect a proportional effect would be me going around to every student and telling you we have a test next week amplification is me putting it on blackboard or Facebook so you're like blasting out to all of your people on Facebook they blast it out to all their people they blast out to that that's why stupid spread so fast on the internet right because everybody's just blasting all this out all the time it's like pushing over tons of dominos so cells are very very sensitive to the non steroid hormones because it already a little dab of hormone is very powerful but then you add the fact that this has this amplification effect where it just keeps going and going and going the protein hormones are very dangerous then we have besides the two classes of hormones we have these chemicals called prostaglandins so I went ahead and threw this in here right now because it's a good comparison to hormones we're gonna see prostaglandins they act like hormones but they're not they're not hormones they have some characteristics of hormones but they have some characteristics that make them not hormones so they are lipids so they are fat based some hormones are there throughout the body prostaglandins and they're very very strong so that's like hormones why these guys are not hormones is you can't store them you make them when you need them and then they go away another reason these guys aren't hormones they don't travel in the blood so where you need them is where they're made so prostaglandins has a lot to do with the inflammation response the fact that when you cut yourself or you get a bug bite it gets all hot those prostaglandins would be made where where your injury is right now I have this horrible spider bite on my arm and it's all swollen and nasty the prostaglandins right next to where he bit me is they were made right there so that's why they're not hormones but they act a lot like hormones so we'll see prostaglandins in several chapters coming up the first one is the inflammation response that I just mentioned the fact that it gets hot and feverish like right now my arms so swollen from this stupid bite we're gonna see it in the blood chapter when we talk about blood clots there's a prostaglandin called thromboxane that causes your blood vessels to constrict and causes the platelets to show up prostaglandins start the labor processes and a lot of the other reproductive processes so these guys again act a lot like hormones but they don't travel in blood we can't store them they're very localized aspirin actually brought blocks prostaglandins so you know you get a pain and fever and you take aspirin and you feel better it's because the pain and fever is being caused by prostaglandins which aspirin shuts off well aspirin also causes causes blood clotting so if you know anyone who's had heart attacks they probably take aspirin every day this is a treatment because it sends the blood because it stops blood clotting but if you cut yourself when you're on aspirin you're gonna bleed like crazy too because again it's shutting off the blood clotting mechanism so we'll spend a lot of time on prostaglandins in other chapters hormones are these incredibly powerful things they're almost like drugs when you inject a drug please don't do that it could be very very dangerous like people OD on heroin all the time because you get a hot shot you stick it in there you don't know and then it's like too late for take C's backsies right if you dump something into your bloodstream and it's too much you can't suck it back out and in under a minute it's everywhere in the body so intravenous drugs even the good ones at the hospital are very very very powerful compared to like marijuana you can't really OD on marijuana you're just gonna want to snack and take a nap long before that happens because the mechanism of bringing the drug into your body is so much different than when you inject things directly into the blood so hormones are the same way it's like these are chemicals that are going directly into the bloodstream they can be very very dangerous if you get too much or too little of them so we've got to control it so we control hormones in multiple ways but the first is there are releasing and inhibiting factors now this is the worst part of this chapter so you just gotta hang in and the releasing and inhibiting factors only affect the pituitary gland specifically the anterior pituitary gland so I don't want you to think the whole chapter is gonna be like this the antor pituitary gland is a pain in the ass but once we are through that one it's not that bad so these are releasing or inhibiting factors basically hormones that are secreted by the hypothalamus so if you remember from A&P one the hypothalamus was a brain structure and the pituitary gland dangles off of it so because the pituitary gland dangles off the hypothalamus the hypothalamus controls it well the pituitary gland has a whole lot of hormones and it's wanting to release them well it has to have a red light or a green light from the hypothalamus to do that so we call the green light a releasing factor and the red light and inhibiting factor so this is only for the anterior pituitary so right now on this slide all you need is the definition of releasing and inhibiting factors but I went ahead and gave us an example that we're going to have to know so there's a hormone it's called prolactin releasing factor this comes from the hypothalamus the anterior pituitary has a hormone called prolactin so if you're Pro something yay you support it right lactam like lactation means milk so if it was up to the anterior pituitary we would all be squirting milk all the time like the Dairy Queen so we men women we would have milk losing from us losing is a fantastic word all the time so we don't want that right we only want milk and women and we only want milk and women that have just had kids otherwise you we don't need this right so if it was up to the anterior pituitary we'd be squirting milk all the time so it's very very important that the hypothalamus controls that right so when it is time for a female to begin making milk which happens around the fifth week of pregnancy the anterior pituitary gets a green light from the hypothalamus so the hypothalamus releases prolactin releasing factor this is a hormone that tells the anterior pituitary that it's okay to release prolactin most of us don't want that so most of us our hypothalamus is currently releasing prolactin inhibiting factor so non-nursing women and men we never want to make milk so we don't want the anterior pituitary to release prolactin so we need this red light so this is only for because I know it's terrible this is only for the anterior pituitary so basically some hormones can control other hormones so this picture is just reviewing some A&P one so you have your little hypothalamus there then you see the red cherry like structure that's the pituitary that's dangling off the hypothalamus so the hypothalamus is going to release hormones that are dumped into the blood because that's how all hormones are and it's gonna affect the anterior pituitary so releasing hormones are gonna say go go go we're going to increase the anterior pituitary secretions and inhibiting hormones saying no no no that's going to decrease we've got to control hormones so how do we slow them down negative feedback so we saw negative feedback in A&P one so this is just giving you the insulin example but it's basically we've got to stay on a sidewalk so it's just like when I walk my dog ideally we would walk on the sidewalk but he's a dachshund so he has to go over to the fire hydrant and smell it he has to go over to a tree he has to go bark at squirrels so he's constantly ying ying and yang Ying back and forth on the sidewalk so the goal of negative feedback is the sidewalk but I will let my dog stray a little bit I'll let him go smell a tree but if he takes off running I correct him so this is how negative feedback works if you start to do something your body doesn't want it will yell at you so if your blood sugar starts to rise your body releases insulin to bring you back down as soon as your blood sugar goes down you stop releasing insulin as soon as my dog is back on the sidewalk I stop yelling at him so almost everything in our body is controlled through negative feedback so we spent a lot of time on that in a in p1 but there are a few things that are controlled through positive feedback so positive feedback would be I'm walking on the sidewalk with my dog and he sees a car and he starts chasing it and I say oh good job keep going and then my dog runs miles and miles and miles away from me I would never want that I like my dog most things in your body you wouldn't want to just take off like a rocket right think about body temperature so you start to get warm and your body goes keep getting warmer keep getting warmer keep getting warmer keep getting warmer and eventually you die or breathing rate you start breathing heavy and your body goes okay let's keep doing that then you pant so it's self promoting it's saying go go go but some warm some hormones this is how they work like oxytocin we're gonna see this guy is released from the posterior pituitary gland and he causes uterine contractions so I've never I've never had a baby but I've had friends that have and it's like the first labor contractions not bad you're like oh this isn't bad the second one's like okay this just getting a little intense by the third when they're screaming profanity and saying don't ever touch me again so it's like one contraction leads to another leads to another leads to another leads to another till the baby comes shooting out like it's on a log ride so some hormones that's their goal most hormones the goal is to regulate but we will see a few hormones where we get this amplification but positive feedback is very very rare besides hormones we have neural control so we can have a nerve just zap a gland so this is especially important for the sympathetic nervous system the fight-or-flight the survival part of your body so the example again that we're gonna see is going to stimulate the adrenal gland specifically the medulla which is the center of the adrenal gland and it's going to secrete norepinephrine and epinephrine which are the chemical names for adrenaline so basically you have this fight-or-flight mechanism that is saying you your brain is going to stimulate the adrenal glands to say okay we need to survive this event so we need it to be really really really fast a deer runs out in front of you you need that adrenaline to kick in a man with a chainsaw comes into the room you need that adrenaline to kick in there's no time to dump a hormone into the blood - cause the adrenal glands to release adrenaline so we just zap it with a nerve because the nervous system is so much faster than the endocrine system so the brain can sometimes control hormones