Lymphatic System and Immunity

hi class dr. Jim here in this lecture we're going to be looking at the lymphatic system and immunology the reason why I put these two together is that they're very closely related the lymphatic system is a third set of vessels that you actually have in your body so we know what arteries do from the cardiovascular lecture and arteries take blood away from the heart we know what veins do they bring the blood back to the heart the lymphatics are actually a third set of tubes that you have inside your body that actually bring any of the extracellular fluid back into the vasculature and back into the circular circulation of the blood and so we're going to look at what the lymphatic system is and what it does today and how it plays a role in immunity the second part of the lecture we're going to look at the immune system in general so we're going to talk about the three basic premises of the immune system were the three layers of the immune system and that you have mechanical barriers on the outside then you have specific white blood cells that do something and then finally you have another set of white blood cells that are very specific and what they target and how they function and so we're going to take a look at all three of those today and then finally when we finish up we're going to kind of look at a little bit of how the immune system doesn't always work correctly and what happens in those situations so come along with me and we'll take a journey through the immune system and why you stay healthy okay so our objectives today is first we're going to look at what is the olympic system and what does it do so why do you have this third set of vessels what's the point what's the point of having these things and what do they do the with the overall body okay what are the major organs in the lymph Lindt system and so we'll talk a little bit about what are the organs that we are necessarily associate them why are they important and what role do they play in your overall systems or in your health we're then going to then delve into the immune system we're going to look at what are the three layers of defense of the immune system so again I kind of touched on that already or talk about mechanical and chemical barriers that you have we're going to talk about a set of cells called phagocytes that basically eat up things like little pac-men and then finally run and discuss the very specific portion which are the specific cells that attack and either attack things outside the cell or inside the cells whether you have bacteria viruses and things like that and so look at all three of those things today as well and then finally we're going to look at what are the major issues of our immune system and so again I'm going to kind of hit home and some of the things what happens when the immune system doesn't play nice and it doesn't it actually works against us and so we'll get these things as well so let's take a look and see what we're going to be dealing with today so the first thing I want to bring up is a lymphatic system and so the overall importance of the lymphatic system and you can see here in this diagram is that it's a set of vessels that basically connect new from every point of your body back into the heart and so it leads you back to the vessels of the heart and so it's a what we call a fluid pickup system so it brings fluid that leaves the blood vessels from either arteries or veins gets around the cells and then gets kind of sucked back up by the system and brought back to the heart so you can kind of think of it like the vacuum system of your body and returns all extracellular fluid back to the heart and back into cell circulation so sometimes you might think of it like when you hit your arm and you get it swollen you might get this really bad swelling that occurs all that is fluid that leaves a blood vessel well that fluid has to go somewhere okay once the swelling goes down and so in order for that swelling to go down you have to have a system to take that fluid out of there now it doesn't just automatically drain back into the blood vessels what it does is it drains into the lymphatic system and the lymphatic system takes all that extracellular fluid outside the vessels and brings it back to the heart where it can be recirculated into the blood and so that's typically what happens with your lymph system okay the other big role that the lymphatic system plays is that it's a defense system and so it's a system loaded with monitors to keep track of what's going on in your body so if you look at the system itself you can see these little knobby things that are all throughout and these are lymph nodes and lymph nodes are very important air is where the fluid comes back and think of this is like little offices or little surveillance spots where basically you have these cells that look to see what's coming into the system and what's leaving so they're kind of monitoring what's in the fluid that's going back to the heart and so it's a way to look at a defense system in a way to eliminate things that might be in your body the major tissues of the lymph system include the lymph fluid so we'll talk a little bit about what lymph fluid is we have lymph vessels which are again vessels that bring stuff back to the heart we have lymph nodes which are the major organs that survey things and look at things and then finally we're going to talk about lymph organs which are important for bringing things back to to are looking at and developing some of the very important immune cells that we're going to talk about today and so you have primary lymph organs and secondary limb Forgan and so we'll take a look at each one of these things in more in more specific senses here in just a second okay so what are the functions of the Lindt system well the first one is to maintain pressure and volume from extracellular fluid and so you can see here here's an atrial and you go into capillary and the fluid leaks out of the capillaries so it's not a complete system of pipes where you have a solid system where fluid stays in the pipes all the time fluid leaks out of your blood vessels all the time and the reason for that is that it kind of bathes the cells and nutrients and oxygen and other things so that the cells get their proper nutrition and so it happens is the fluid leaks out of the blood vessels and around the cells and then returns back into the blood vessels through what is called the Lindt system and you can kind of see how this works so these lymph vessels are all throughout the body and basically they kind of siphon the liquid that comes off the blood vessels back into the lymph system and then again once you have these little checkpoints that basically say what's going on or is there anything that we should be worried about in this exercise either fluid and here gives you a better idea of how this lymph network works and so you have these vessels again atrial Zoar are arteries and atrial that turn into capillaries and these capillaries turn into venules and then veins and what you can see here is that fluid all the time leaks out of the capillaries and that's important to bathe these cells that are on but you can also see that you have a third set of tubes that are kind of in-between here that basically collect all the fluid that leaks out of the vessels and this is important so that the fluid that leaks out gets returned back into circulation eventually in that the final place that returns is back in the heart and so one it's a way to maintain that volume of exercise or fluid so any fluid that leads the blood vessels needs to return to circulation and the lymph vessels are a series of interconnected tubes that carry the fluid back to the heart and so that's the point of the lymphatic system now the other part of the lymphatic system is that it does play a major role in your immune system and the defense network and so many of you have probably felt this before if you've ever gotten a cold and you can feel your neck and it feels kind of tender sometimes you feel this long these lumps that are in your neck or maybe under your throat and what those things are actually lymph nodes that are swollen because what goes on is that you have these lymphatic systems that bracelet basically bring in the fluid you have these B and T cells which I'll talk more about a little later on that are packed in these lymph nodes and what they're looking for any things that shouldn't be there and so they're constantly surveying the fluid that comes through and if they see something they don't like they respond and so that's a big important part of the immune system is that if they see something and like they respond and that's what the swelling you feel and I'll talk a little bit more about why you feel that swelling and a little what but what happens is if there's nothing that is needs to respond the fluid continues on leaving the lymph node and I'm back towards the heart okay and so that's something that we have to think about the other thing that you will feel is the B and T cells there is a reaction and they do bind it at what you see is that the BNT cells react to those things and then they start to make more B and T cells and so when they make more BN T cells they get swollen because they get jam packed cells and that's the feeling that you get in your neck that's what you feel when you get sick and that's telling you that you have an active infection going on and your immune system is responding correctly and so the fluid is monitored for any foreign substances and if the material is seen the immune system responds quickly so if there's any foreign material boom your immune system responds and then you get that swelling in the neck and you know you're going to be fighting a cold or an infection off and so that's very important okay all right so what is lymph lymph is a fluid okay and it's any fluid that enters the lymph vessel and so typically you can see here here's some lymph fluid it's kind of a yellowish green color that you have it stick typically a mixture of blood plasma that leaks out of the out of the blood water dissolved substances like protein salts and minerals and then immune cells the white blood cells and so we're going to look at more about what these immune cells do and what they react to in a little while but these are very important in the limb system again like I said the link system is very important for defense now the lymph vessels themselves act a lot like veins and so what they have are these big holes and then that allow for fluid to enter in on the side and then they have these valves that are one-way only and so what that means is once fluid comes in it can escape out back through the back way so it pushes the fluid back towards the heart and so they're very similar to what we see in veins with the valves and that stuff and again One Direction valves keep the flow from returning back through the lymph nodes and that and so the fluid can come in but then gets pushed back automatically to the heart so it's a constant system of pushing fluid back towards the heart and back into circulation okay so what are some of the organs of the Lindt system and so the organs are divided into two groups you have the primary organs which are concerned where the blood cells develop and mature okay the first one are the bone neuron this is where the b-cells mature and so we call these b-cells because they're from the bone marrow okay they must mature in the bone marrow and so this is the substance that's found in the middle of your big large bones that you have the bone marrow this is packed with stem cells these cells constantly make red blood cells white blood cells and a lot of other cells that you need every day for you to function so a lot of protein synthesis goes on here a lot of mitosis takes place here and so you have a lot of things going on in the bone marrow the second thing that you have is the thymus and the thymus is where the T cells go to mature so the T cells actually develop in the bone marrow but then they mature and become adult T cells in the thymus gland now if you're asking where's my thymus gland it actually sits kind of right above your heart in the middle of your chest and as a baby you're actually have a very large thymus gland but as you get older and older and older you start to shrink shrink shrink and by the time you're about six years old your thymus gland is almost non-existent and that kind of explains why you see that your immune system weakens as you get older because your systems are not designed to have a strong immune system as you get older because the thymus gland gets smaller and smaller you make fewer and fewer t-cells so your immune system just doesn't work as well and so that's one of the products of aging in that sense okay the secondary organs include anything any other tissue involved with the lymphatic system so what's included here the spleen so the spleen which sits right by the stomach so you kind of think about where it is kind of in the lower and the upper abdomen area you have the spleen and again that is a very large lymph node which again has lots of B cells and T cells that are surveying things it's also the site where blood cells go too and so you can live without your spleen but again you're more successful when you have a spleen in those cases the other big one are tonsils so a lot of you might have seen your tonsils before they kind of sit in the back of your throat and if you've ever had a swelling of your tonsils sometimes you can feel it in the back of your it kind of closes up your throat it makes it feel like an itchy sweater and so it can be inflamed and so if they constantly get inflamed and things get caught and might have problems with sleeping and things like that you might have elective surgery where you might actually remove the tonsils and again you still function as a normal person in your immune system works just as well the reason why they remove them is because you're having either issues with eating or breathing or something else and that your tonsils are constantly to being swollen in these cases the other ones are any lymph nodes of the body and again you have a major concentration of lymph nodes and you're growing your armpit and your neck and so that's where you really feel it and so many of you have probably had the flu shot this year and so when you get the flu shot a lot of times your arm gets sore for a couple of days and then maybe like two or three days later you might feel some pain in your armpit you wonder why why do I feel this pain what happens is is the flu vaccine actually works its way through the lymphatic system so it gets deposited in the muscle it eventually ends up in those lymph nodes that you have in your armpit and what goes on there is your immune cells those B and T cells see that flu vaccine and say AHA this is something I need to make a response to and so what you feel when your opinion you have the pain in your armpit is that basically you're feeling that immune response is taking place and so it's actually making t-cells and b-cells to be reactive so that once you are ready to go you're now protected against the flu for that year and so that's a real important thing and so that's why the lymph nodes are there they're there to survey see what you've come in contact with and ready to tackle it if you need be okay and so that's the lymphatic system in general so the next part of the lecture we're going to look at is the immune system and so we're going to see why you do so well and why your body responds and blocks you know these pathogens that are constantly infections that are out there that are trying to get in and so we're going to look at the different types of immune systems that you have now if you remember I may be back from the prokaryotes and that stuff I talked about infections and parasites and things like that well what we call any foreign substance that enters into the body we call that a pathogen and so this can be something as simple as a virus and so obviously influenza is big because we always worry about flu during the fall fall in winter and then obviously in the news lately Ebola has gotten its rear ugly head out and so you see this thing and you hear about it and yes that is a virus and so that is considered a pathogen another thing could be bacteria and so we have all different types of bacteria that can cause diseases and again we talked about that and the prokaryotes and what they can do we have funguses that can cause disease we have protozoans that can cause disease and get into the body and again we've looked at this already when we've done the survey in the last couple weeks and then the multicellular animals now you guys looked at worms a couple weeks ago and again we talked about the Flynn aerial worms the flukes the tapeworms things like that all these worms can cause problems inside the body and this is what your immune system is geared to fight for and so all these things are all called pathogens because they get in and they cause disease okay and so the immune system is a serious defense mechanisms to protect hunt and destroy these pathogens and so that you can live a very healthy life and so that's the whole point of having an immune system most multicellular organisms have some formula Muse system to protect them against the very pathogens that are out there because we're bombarded every day with tons of tons and tons of pathogens and again most of time we don't get sick because our new system does a very good job and keeping us healthy and so we're going to look at what these mechanisms are so I talked about the three layers of disease before or defense and so the first layer and I always describe these either being specific or nonspecific and what I mean about that is that if they're nonspecific it doesn't matter if they're a virus bacteria fungi protozoa these guys tend to block everything and it doesn't discriminate what the thing is they just want to block it and get rid of it okay so we have this first layer of defense it's nonspecific meaning it can tackle all types of differ pathogens and doesn't matter what you are now the first thing we can talk about is mechanical barriers and these are things on the outside of your body that protect you from things actually getting in and this includes things like your skin which is a very solid protection and the only time you get sick is when the skin rips or tears and you have lots of mucous membranes so any opening that's open to the outside world including your mouth your nose your e through your anus is loaded with mucous membranes around it and what these are are the different series of sacs that allow you to basically that produce mucus and catch things from coming in and getting you you know protecting you from getting you sick so what happens is these mucous membranes are there to trap the outside pathogens from getting in in the first place and so they do a very good job so especially in your nose in your mouth where most of the things actually come into your body those are loaded mucous membranes which actually protect you and trap these things from even getting any farther than where they go either in the nose or the mouth the second type of mechanical barrier drink are called chemical barriers and these things include sweat tears saliva wax mucus and stomach pH all these things are different types of chemicals that we have that have ant a pathogen properties a lot of them have antimicrobial properties meaning that they attack bacteria they can attack protists they can attack even fungus and that stuff and so there's reasons why we produce these things sweat tears and saliva all have lysozyme lysozyme is an enzyme that goes in and destroys pathogens on contact wax in your ears help trap pathogens so they don't get into your ears and that's tough that's the reason why it produces and again new kiss is a very sticky salty substance that allows things to stick in catch and capture it and then destroy it and so that's the reason why you have it now the last one I have down here is stomach pH and you may not realize this but most of your immune system your first layer of your new system deals with swallowing things and so when you sleep at night you have cilia in your respiratory tract so your breathing things in all the time and your cilia do a very good job and the mucus trapping those things and what the cilia do is push those things up and while you sleep in the middle of night those things work to the top of your throat and then you swallow on whether you realize it or not you swallow lots and lots of things and the reason why you swallow is because your stomach acid will go and destroy all those pathogens and most pathogens cannot tolerate a very strong acid and so the acid pH of your stomach destroys those pathogens and it does a very good job so those are all the first layer of mechanical and chemical barriers to protect you now if a pathogen somehow it gets by these first layer mechanisms you have a second layer which again is nonspecific meaning it will go after any of these things and it doesn't care what it is and these are typically what we call phagocytes and phagocytes if you want to think about it in terms of real-world type of thing think of it as pac-man most of you probably have heard of pac-man before maybe you're a little young for that but pac-man was a video game from the 1980s where you went around chomping little dots okay and these white blood cells go around chopping up little pathogens and so you have a couple of different type of phagocytes one of them being called neutrophils which are very important they go in and destroy things and kill things and then you have monocytes which are a little bit more important in the sense that they chew things up and then they present it to other cells and so again these guys go in like little pac-men eating up the pathogens when they come across them once they sneak through those first line of Defense's okay so the second line you have is these white blood cells that do this now another type of white blood cell you have are called granulocytes and granulocytes release granules that destroy pathogens and so these are like ticking time bombs that you can kind of throw so think of them as like little grenades when they see a pathogen what they do is they release their granules and they stimulate the immune system to attack and so they're kind of like little ticking bombs or little grenades that go off all the time when a pathogen comes in their way and so what they do is they react react they release these granules and then you have an immune response and these include things like basophils and eosinophils and mast cells which all interact and respond to these different types of pathogens okay now another thing that you have inflammation and this is our body's own reaction to an infection and so typically when you have an infection and that just means basically you have disease inside your body that's causing the immune response to occur you get this series of the chemical events that basically happen and so what happens is that you get redness swelling heat and pain and that's typically what we call an infection and so you have the redness which is basically your blood vessels dilating and releasing the white blood cells and extra fluid to help fight disease swelling because you release that fluid outside the vessels remember I told you you get extracellular fluid well if you release more fluid from your blood vessels you're going to get more swelling the heat is due to again the basal dilation the release of blood into the extracellular space so you feel more heat and then the pain is because you have lots and lots of nerve endings if you remember back to the integrant airy system I said you have lots and lots of little nerves that run through your skin well as soon as you have more swelling and pressure against those things they tingle the nerve and then you feel pain and so that's the whole idea and so it kind of tells you that hey you got something going on here and if it gets bad enough you might want to get it checked out and so that's your body's own response to an infection and so that's what you have and that's called inflammation okay and so we describe this as redness swelling teeth and pain all right now the third layer of defense is very specific what I mean about that is that it has specific cells that attack specific pathogens and so you have these cells that are marked for only a specific type of pathogen the two types of cells that we discuss are lymphocytes and these lymphocytes are specific white cells called B cells and T cells now if you remember back to the lymphatic system and I talked about where these guys mature the B cells are from the bone marrow the T cells are from the thymus okay and these guys have two specific roles the B cells and TAC evaders outside of cells and the T cells and TAC invaders inside cells and so they do two specific things so the B cells again from the bone marrow produce antibodies these are proteins that allow you to flag and attack pathogens that are floating in the out sigh so these are proteins that bind to foreign materials so here are the antigens and so antigens are foreign proteins and your antibodies are what are made to bind to these antigens that block the that block these reactions and so you make lots of these proteins throughout your blood the antibody comes in and binds to the pathogen and stops it from being active so it's a way to neutralize and destroy the pathogen by releasing these little flags ok the other types of cells you have are called T cells and T cells are from the thymus early maturing the thymus that's why they're called T cells and these are cells that target and destroy so they look for cells that are not looking right and they say ok it's time for you to die cell and it goes in and destroys the cell and so they have the cytotoxic Nature tool ok and so both need to see the pathogen first in order to respond because they're very specific and so you only have certain types of BN T cells that will only react with certain types of pathogens and that's very important so they're very specific ok and then both what the nice thing is is develop memory so if you get exposed to something at some point in time in your life your immune system will remember that keep a mark of that and kind of keep a harddrive of it so that if you have anything that you come in contact that look very similar it's ready to respond and you don't get sick again and so I like this little cartoon because after it eats and chomps away the pathogen it has dreams about that pathogen and anytime that pathogen comes back this guy is ready for the attack and ready to strike again and so that's a really cool thing so your cells actually make memory and so those are the three lines of defense and so we have mechanical and chemical barriers which are the first line these actually protect the body from outside and pathogens if the pathogen somehow make it through the first line of defense you have the second line the second line comes in and prevents the infection by E going in and eating things and again very not specific doesn't matter if it's a virus bacteria or what it is goes in and eats these things up if somehow the pathogen gets behind the second line of defense you have now this very specific third line of defense that says okay let me make a really good spots I'll either attack it from the blood if it's in the blood or in the extracellular fluid or I'll see a cell that's infected and I'll take out that cell before the virus can spread to other cells and so this is what the immune system does it does a lot of different things having these different levels and you can see how they all interact now the immune system does a very good job throughout most of your life however it can cause problems and probably many of you have had some of these issues and so now let's talk about some of the issues that are we deal with with the immune system the first one being allergies and allergies are actually an immune response that you have to certain things that are found in the environment okay so again these are foreign materials but what happens is your body makes an overall overwhelming response to these or hyper response to these pathogens okay so what happens is that you get an initial contact with that allergen you make a response and now what happens is now you have made this pre response ready to go that the next time you come in contact with it your cells respond overwhelmingly and cause you to feel bad now you can have two types of allergy responses you can have a localized which includes itchy right a red itchy watery eyes sneezing can just congestion and runny nose itchy and sore throat post nasal drip and cough can these things like hives could cause diarrhea could cause other things that happen on the skin and a lot of times what people will do is if they have severe allergies that are local what they'll do is they'll go in and they'll get a skin test done and what you can do is actually inject a little bit of the antigen or protein underneath the skin and see if you react so you can see on this person they had a skin test and you can see that you have a lot of different reactions to a lot of different things so this person is allergic to a feather cat dog horse - pollen grass and Daisy birch pollen and maybe even a little looks like clean pollen but I'm not sure what plane pollen is but any of these things or plant pollen maybe that's what's supposed to be and so a lot of these things again you can see how you would have a response and so anytime you have an allergy it's your immune system response into this foreign material that you've brought in and makes this hyper response now that's a localized infection however sometimes you can get a systemic infection and so this is a little serious cases so you may have heard of this before it's called anaphylactic shock and essentially what this is is your body your immune system makes such an overwhelming response that your body just says oh my gosh and it starts going pumping and working really hard and what that causes you to do is basically shut down your whole body system the response is so great that your organs start to shut down your respiratory system starts to shut down and your cardiovascular system starts to shut down everything doesn't work anymore you go into shock and then you die and so this is why people carry around an EpiPen so if they hadn't they know they have severe allergies a lot of times to bee stings or to some other things maybe peanut allergies they use this because they need to make sure that they don't go into this anaphylactic shock and if they do they can inject this pen to keep their heart going it's basically a boost of adrenaline to keep their heart going so that they can get medical attention right away so if you're one of those people that know that you have a severe allergy to things you might want to consider carrying around an EpiPen just in case that if you don't want to have a situation where you go into anaphylactic shock and possibly die now you know a lot of people have these things and I don't want to make you frightened of these things but you will know if you have severe allergies or not and so again you can always get those treat treat it and looked at by an allergist so make sure if you do have any of these things that you get them checked out okay now another issue that you can have with the immune system is the blood type and I don't mean an issue of what type of blood you have but it does kind of play a role in how the blood system works okay same type of thing now if you remember back to when I talked about blood in the cardiovascular if you've already watched the video you know that we have really four types of blood you have a B a B and O and basically what that responds to is what type of protein on your blood if you have a type blood you have this protein on your blood cells if you have D type blood you have this B protein on your blood cells if you have a B you have both the a and the B and if you have oh you don't have either one of those proteins on the blood now the other thing you make when you have this blood type are called antibodies and antibodies again are like little snipers that go out and attack foreign material and so they're looking for the opposite blood type so if you come in contact with the opposite blood type these antibodies respond and destroy those blood cells and so you make the opposite of whatever your blood type is so if you're an A type blood person you make the anti B antibody if you're the a of your B type blood you make the anti a if you make the O you actually make both types because you can't have a or B blood and if you're a B you actually don't make any antibodies so what does this all mean when we look at the whole realm of things and so this just kind of shows you in words what I mean here by saying it do you make an antibody or not so what does this all mean well this means if you have type A blood you cannot get B blood or a B blood however you can have Oh a blood because you have the protein or you can have o type blood because basically you don't have any proteins on there your body your antibodies are not going to respond because the O doesn't have the D antibody so you can have those blood cells likewise if you're the type D type blood you can't have a or a B however you can get B blood or you can get o blood if you're a B you can have any type luck because you don't worry because you don't have any of the antibodies that will bind and attack these cells and then finally if you have o the only blood you can have is Oh tight blood and so it is a universal donor because you can give Oh to anybody however the only one that can receive all blood types is a B and so they're the universal receiver okay so if you're the lucky type and have AED you can get any blood type and not have to worry however if you're one of these other types you have to worry about these different blood types and so if you get the wrong blood type it can cause serious complications what happens is your bloods blood kin lice and you can die faster then if you didn't get a transfusion at all so if you get the wrong blood type your body will respond destroy the new blood the blood cells that you just received and since a B types have no antibodies they can receive any of the different types of blood and so that's really important so really knowing your blood type is really important but the reason why they always ask for otech donors is because anybody can get o type blood so that's why they really like to get the Oneg donors and I'll talk about what negative means here in just a second so that's one of the things now another type of blood is this Rh factor and again I talked about this with the blood in the cardiovascular system Rh factor is another protein found on blood cells and it's called the Rh factor and it stands for the rhesus factor or Rh factor you either have it or you don't serve either positive or negative okay and now the only time we worry about this is if you're an Rh negative mother and I have a nice little diagram here and sorry that it's kind of fun and fuzzy but what happens is if the dad is Rh positive the baby is going to be Rh positive because it's a dominant recessive type of thing and anytime you have the dominant you hide the recessive and so in this situation if Dad is Rh positive in mom is Rh negative the baby is going to be Rh positive and what happens is some of the blood can mix between mom and baby well when that blood mixes during delivery and during the pregnancy mom will develop antibodies against that Rh factor because it doesn't normally see it and so it thinks it's foreign so the problem that happens is that when mom makes these antibodies if mom has a second baby with the same father that's Rh positive that baby is Rh positive but now she has antibodies that will attack the baby okay this was a huge concern that people didn't understand back in the 1950s so people would have their first child normally perfectly have healthy happy and then after that they've had a series of miscarriages they could have two three four or five miscarriages after that first baby and not understand why that was happening it was actually due to this rh- factor we didn't know what this was until about the 1970s and so now they know what your blood type is and so if you're a pregnant woman they're going to look to see if your positive and negative and if your negative you get a shock which is called rhogam and rhogam is actually used to protect you from actually making antibodies towards the baby so that you protect the baby so you don't make any antibodies towards it and so baby can be nice and healthy and so now we see in moms that are Rh negative they get the couple of shots so they get one at the first pregnancy like at the beginning and near the end and then any subsequent pregnancy they'll get another shot and again that protects them from having this and now these mothers can have multiple babies now without worrying about having these miscarriages and so it's actually revolutionized how many people can actually have multiple births throughout the whole pregnancy or the fertile years of the mom's life and so again this is why we worry about the Rh factor most other things we don't worry about with the Rh factor we have to worry about with the RH - mom and the Rh positive baby okay now some other issues included are Auto immunities and auto immunities are when your immune system starts to attack yourself and so it no longer recognizes yourself and it says I need to attack myself and what happens is it starts to destroy it and so there are several diseases and you can see here in my chart all the different diseases that might be out there and so you can see they and they affect all different parts of the bodies here's a list of just some of the diseases that there's quite a few that are out there that cause serious problems in people and so you might have MS you might have Graves disease which affects the thyroid you might have lupus which is one that affects the DNA of cells Crohn's disease which is a gastrointestinal asthma which is in the lungs rheumatoid arthritis which is the joints and again you can have lots of different diseases and again all this is is that it's the immune system that's now attacking yourself and so unfortunately what happens is that there's really no cure for these diseases but what happens is people will go on immune suppressive drugs so you go on these immune suppressive drugs to eliminate the autoimmunity or prevent or autoimmunity from occurring however now that you suppress the immune system you're now more at risk of other infections so one of the big drugs that are out there now that you may have heard if you ever watched the news or on TV is Humira Jumeirah is for asthma and autoimmune type of situations so you might see it with plaque psoriasis that's another one so a skin disease where your immune system is attacking so you go on these things like chimera or other drugs and so one of the big warnings out there is that it may cause other infections and that's because we can see immune system so that the immune system doesn't attack yourself however when you weaken it the second problem is is now you're more likely to have infections and other things because your immune system doesn't work as well anymore and so it's kind of a double-edged sword and so as you lower the immune system so it doesn't attack you you also now increase the risk of having more infections and so that's something to worry about if you have these situations now another thing that we worry about are issues with the immune system are transplants and so this is something that obviously hopefully never have to deal with but sometimes your organs tend to fail and so and when they start to fail you need to get a new organ somehow and so we get these things called grafts and grafts or any tissue that has been taken from one part of the body and put into another part of the body you can see and on the right here I have lots of different things showing you how many different transplants were done in the United States in the year 2000 and so we have these different types of graphs so the first one is called an autograph and that's basically when you take a graph from one part of the body and use it for another and the typical example that is a skin graft so you have like a burn or something and what they'll do is take skin from either the foot or wherever you have a thick part maybe sometimes on the back and they graft it on a new part and they can regenerate the skin in those places now if you're lucky enough to have an identical twin which I'm not lucky enough but if you do have one you can actually get something called an ISO graph and that's basically taking tissue from your twin and put it into your body now an identical twin has the same DNA has the same immune system so they're going to behave the same way now typically what people will get if they need a graph is going to be an allograft which means that they take it from the same species so you get one from another person so this could be something as simple as like a kidney or maybe some skin or other things like that or maybe as detrimental as something like a lung or heart where these people have died and now they donated their organs and now you get those different things to these people and again you have to match these people because the immune system is out there ready to attack foreign tissue so if it doesn't recognizes that recognize the new tissue it will reject it the other type is now called a xenograph and these are typically what we see when we replace certain parts of the body so one of the most important xenografts that we have out there right now are valves on the heart sometimes your valves start to fail and they leak and so sometimes you can actually get them replaced with pig valves because the pig heart is about the same size as a human heart and so the valves are about the same and so a lot of times what we do is actually use those valves from pig hearts from the slaughterhouses and put them into humans and they don't seem to have too much of an immune response which is very cool so some people actually are out there that actually have different animals inside of them they probably won't admit it to you but they do have those things and that's called a xenograph okay the problem is with any of these transplants is that rejection is always a step away because you have your immune system what is your immune system looking for foreign tissue and so anytime you put foreign things into your body your immune system is there to attack and so again it's ready to attack that you don't want it there and so people with transplants for the rest of the life are going to be on immunosuppressive drugs so just like those autumn immunities the problem with immunosuppressive drugs is now you've now raised the risk of getting other infections so people with transplants are really weary when you have someone with a cold or flu by them because they're going to be more at risk of coming down and catching that cold or flu so they're going to be sick more often because your immune systems don't work as well and again they tend to avoid major social events because they don't want to get sick from other people and that's just because their immune systems are now okay now one thing that is interesting that may change this whole field in the next 10 to 15 years is stem cells and we're starting to see this happen and take place now I talked a little bit about this in the molecular biology a couple of weeks ago and that we're actually using these stem cells to grow new organs so you can kind of see here is that they're actually using cadaver parts to grow new parts of the trachea or windpipe that have been damaged and it can regrow that using cadaver parts and seating these cells or being as more complex of growing a new heart and so what they're using are these adult stem cells they're taking a cadaver heart as a scaffolding they add the stem cells to it it builds a brand new heart that looks just like you and now what you have eventually essentially eliminated as any form of rejection because the cells are exactly like you and that's the really cool thing that's the exciting thing that's going to come up is that we might be able to eliminate the whole need for anything where again we don't have to have transplant lists and we don't have to worry about putting people in a newness oppressive drugs because the tissue is going to be there's it's going to be theirs for the taking and that now the immune system doesn't respond and say I need you out of there get out type of thing and try and attack and have eventually reject it and so that could be very cool for modern medicine now the last thing I'll talk about is deficiencies and that's really important and that means Lee means a loss of the immune system now you can have a primary loss of the immune system and this is typically genetic when you're born without certain things so you could be born without b-cells you could be born without t-cells and so this is where you're born with the condition and so in a situation like this many of you probably have heard or maybe someone's talked about that the boy in the bubble and this is because he doesn't have any immune system so anything in the outside world could essentially kill him because he has no immune system so he has to spend his whole life in the bubble and that's really kind of scary you know you know if you get born with the immune system you know he looks like a perfectly healthy kid but unfortunately anything out there in the world could potentially kill him because he has no immune system to kill him or the immune system to protect him and so that's a big issue okay and that's a primary disease most of us deal with secondary types of deficiencies and so some of them are acquired over time ordering our lifetime now most of the ones that we get are temporary and so this deals with stress age and illness we get sick our immune system goes down but eventually we repair ourselves and get back together and again a lot of things can happen that way now the more serious condition is when you have a permanent loss and this again can be something as like HIV which destroys your t-cells you eliminate those t-cells and now you've lost a big part of your immune thing and again immune system and again the problem with that is that that's an important part of your immune system and when you lose those cells you lose a big part and so now you're at risk of more infections and so people that have HIV and AIDS eventually succumb to secondary infections is that the HIV and AIDS that kill them it's not the loss of t-cells that kill them it's those secondary infections that they get they get more cancers they get more immune responses they get more things that attack and destroy their bodies very quickly and that's because of these and secondary infections that kill them through the immune system the lack of the immune system and so there's some big problems that go on with this and so these are all secondary because you acquire them over your life okay so we've come to the end of the lecture and know you're probably saying thank God I'd learn more about the immune system but I really like to talk about it because I think it's important to understand the defenses that you have out there why does you why don't you get sick every day well there's a reason why we have we're about barded every day with millions and billions of bacteria and viruses and it's very rare that we actually get sick okay might get sick maybe once a year if you're really lucky maybe twice and that's and that's really good and that's because we have really good immune systems that protect us so let's look at what we looked at today so to summarize we have a lymphatic system which is a series of tubes and tissues that function to return exercise and fluid back to the circulatory system and it also monitors for pathogens so it's very important not only to bring the fluid back to the circulatory system but also to look as a defense mechanism the lymphatic system is made up of two primaries us or two sets of types of organs you have the primary which is the bone neuron thymus remember and t-cells that's where those are made and then you have the secondary organs which include the spleen councils and other lymph nodes and again these are there to survey what is coming into your body this is where it's fun think of that flu you remember when I talked about the flu vaccine our pickets or it's because your lymph node lymph nodes in your armpit are responding to that vaccine now the immune system is very important for protecting and defending your body against any foreign material which we call pathogens pathogens can be viruses bacteria fungi protists worms any of those things that are not supposed to be there you have three lines of defense the first two are nonspecific meaning they attack whether it's a virus bacteria fungi or any of those things and they go for it and they just attack and again it's basically the first line protects you from keeping things out of your body if they make it into your body your second line goes to work and destroys them like little pac-men and then the third line of defense is your key T and B cells which are very specific and then they attack with specific proteins and other cells that go and destroy so very specific and then finally if you have issues with your immunity again we talked about all these different things like allergies allergies always bug people you can have auto immunities which can cause your body not to recognize self anymore in your meat system actually do attack yourself and then we talk about transplants and rejection and loss of immunity so lots of different things that can happen to your immune system and cause you to have more problems especially as you get older so with that we've come to the end of the lecture if you have any questions about anything I'm really excited to talk about this stuff please feel free to ask me or miss Jill about anything that you might have we're getting close to the end next week is the last set of lectures so hope you're looking forward to that and in that and if you have any questions please let me know so again I thank you for watching and I'll see you next time

Channel: Edward Kerschen

Views: 66,252

Rating: 4.9225807 out of 5

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Id: DXOAOmyh7-E

Length: 48min 21sec (2901 seconds)

Published: Mon Nov 17 2014