Alright, so we will begin with chapter 12, the discussion of the lymphatic system and the immune system. So if you look up at the screen, you can see an image of a macrophage, a cell within your own body eating up a bacteria. Looks like something out of a science fiction novel where you got these cells which are working to fight against these. outer space aliens like the recent Tom Cruise movie where he's on the beach and he's fighting up against all these animals, aliens.
And you've got the Avengers, like a coordinated team, working to fight against a foreign invader, which is like what occurs within your immune system. You're constantly under attack by these organisms that make the sci-fi graphics effects in the movies you see look like the doodlings and drawings of a... three-year-old no offense to any three-year-olds. Actually they are very creative so I'm sure they make some good headlines.
But I'm saying that we are constantly under attack by these different organisms and we have the lymphatic system and the immune system which function to work to keep us healthy. And we don't really appreciate the immune system until we are actually ill. So the lymphatic system. So we talked about how we have these arteries which bring in arteries which bring in nutrient rich fluid to the tissues, we have veins which suck them out, but in between you have some fluid called interstitial fluid.
You have the lymphatic system, it functions to suck up all that excess interstitial fluid and bring it back into your circulation. And it functions to cleanse these structures, cleanse that fluid through your lymphatic vessels. So the lymphatic vessels are you got these little lymph nodes, these little lymph nodules.
You can view these lymph nodes kind of like army bases. These lymph nodes, these are where you can find kind of accumulations of immune cells. You can see you find your B cells, T cells, macrophages are found within these little army bases within the body.
Some other lymphatic organs, you've got the spleen. The spleen functions to eat up those worn out red blood cells and function as a reservoir. You can have a lymphatic organ called the thymus. Let's see a good image of that thymus.
So the thymus, it functions to mature T cells. And you want to have your police officers in a bad neighborhood. So your mouth, it is a bad neighborhood filled with bacteria. So you want to make sure you've got some police officers there.
So you've got these tonsils. These are some police stations which can function to monitor the presence of different microbes in the mouth and can eat them up. Same thing, you have these little pyrus patches, which are located in the small intestine.
So you've got the lymphatic organs, I mean the lymphatic vessels. which function to suck up all the excess fluid. And then you've got the lymphatic organs, which function to as bases where they can execute that response.
So we'll begin talking about the lymphatic organs. Like I said, that lymphatic system, right, it functions to suck in that excess fluid. And just like the cardiovascular system has vessels, the lymphatic system has vessels as well, which are like straws that suck up that fluid.
So we see an artery right here, we see a vein, and we see the tissues. And in between you have that interstitial fluid. So your hand would be your artery, and this would be a vein.
And then in between would be that interstitial fluid. And then the lymphatic vessels, they function to suck up that excess fluid. So lymph is that excess fluid that is inside the lymphatic vessels.
So once that fluid gets into the lymphatic vessels, it is called lymph. It's just like. a sewer water. So sewer water, when it's outside the sewer you could call it rain water.
But once it's in the sewer system you call it sewer water. Same thing with the lymphatic system. When that excess fluid is outside of the lymphatic vessels it's called interstitial fluid.
And then once it goes into those vessels it is called lymph. And the lymphatic system, right, the fluid moves through the lymphatic system in a similar way as the fluid moves through the veins, through that milking action of the skeletal muscles, right, and also through, you know, respirations as well, right? Your muscles kind of contract that lymphatic vessels like the milkmaid squeezes the udders of a cow.
So when people are immobile for a long period of time, they can develop, you know, edema because they're not moving and they're not moving that lymphatic fluid back throughout the body. Or if somebody is, has gained weight or if they're pregnant, right, it could inhibit the flow of that lymphatic fluid. up through the lymphatic system and they can get swelling within the tissues.
So that lymphatic fluid, it ultimately moves back to the heart. It flows back, it sucks back and will be deposited into the subclavian vein. So here, so you would cleanse the fluid, it would go into those lymph nodes. Dirty fluid goes in, clean fluid goes out.
Dirty goes in, clean fluid goes out. And then it will be deposited right into the subclavian vein. So on the... On the right side, it will go into this little area called the lymphatic duct and then dump into the subclavian. So the lymphatic duct, it drains kind of the right portion of the arm and then the right torso.
And then the thoracic duct, it drains. So you see the right portion of the leg, the abdomen, the left leg, the left arm, all. drained in by the thoracic duct of the fluid gets sucked back in.
It's just like if you take that sewer water, you cleanse it, and then you clean it first, and then you bring it back into your water system so that you can then use it again. So within those lymphatic vessels as well you've got, you have valves, just like you have valves within the veins. And just like within the vascular system, you have arteries which turn to, you know, arterioles which turn into capillaries.
It's kind of the reverse with the lymphatic system. You have these, right, lymphatic capillaries which kind of grow into these larger structures called lymphatic vessels which will lead up to your lymph nodes which will function as filters just like you filter out the fluid within your own. water that you drink, those Brita filters. So as I said you've got the on the, on the, there you go.
So you have the thoracic duct that is draining this left side. I'm sorry, the right, sorry, the right lymphatic duct which is draining this right side, the right lymphatic duct, drains into the right, then dumps it back into the subclavian vein. Think your clavicle, right?
Subclavian, right? Dips underneath your clavicle, right there. And then the thoracic duct, which drains the left side. So think LT, think LT, left side, draining the thoracic, drained by the thoracic duct right up here, just like a straw. So the lymph, so within that lymph, so remember that lymph, that is the, that is when that interstitial fluid goes into the lymphatic vessels.
So within that lymph you can find a whole bunch of different organisms. You can find bacteria, right, bacteria, those single-celled disease-causing microorganisms, you know, staph, strep, anthrax, all these different types of bacteria. cholera, all these different types of microorganisms. And then, you know, viruses, like the rhinovirus, the flu, rhinovirus, the common cold, influenza, the flu, you know, all of these, HIV, the virus, all these different types of viruses.
Cancer cells, right, these cells that can metastasize, guess what, right, these lymphatic vessels, they can serve as a means in which you can transfer that lymphatic fluid. but they can also be alleyways, highways in which cancer can break off and metastasize, as you all talked about, within your projects. They can break off and metastasize through those lymphatic vessels, and then cellular debris, little excess particles can be transferred through that lymph.
So within the lymph nodes, so right here, so we'll see it, we'll view it. you a large view and then we'll look at a small view of the lymph nodes. So right here we see all these lymph nodes.
We've got cervical lymph nodes, within the necks, axillary lymph nodes where no breast cancer can metastasize to. You've got these inguinal lymph nodes where no prostate cancer or testicular cancer can possibly metastasize to and they also serve as a draining function as well. So right here we see them in a large view and then we'll zoom into an actual lymph node. This is large and then we'll zoom in to see what's inside the actual lymph node.
So within the lymph node, you have areas that will have your macrophages, which are like the Pac-Man. pack women and then also you'll have areas which have your lymphocytes and as we talked about when we talked about the blood you have your b lymphocytes which turn into plasma cells which release antibodies and then you got your t lymphocytes which fight against which fight against viruses which fight against cancer etc so the cortex just like you got that cerebral cortex is the outer portion of the brain you have the the cortex of the lymph node this is the outside Within it, you have these follicles that have these germinal centers. So whenever you hear that word germ, it's talking about growth. So we'll talk about the reproductive system where we got these germ cells which will grow and multiply and develop into our sperm and eggs.
So within these germinal centers, you have these follicles which will contain many, many of those lymph nodes. And when people get swollen lymph nodes, when they get an infection. That is because those lymph nodes, they're multiplying.
Just like you need more troops if there's a war, you need to produce more lymph nodes. So these lymph nodes will swell. They'll multiply to create more of those lymph nodes within these follicles. And then we got the medulla.
I think the middle is the medulla. Within the medulla, you'll find those macrophages which will eat up different types of pathogens. And just like with the filter, you bring the fluid in, you cleanse it, and then you flow it out.
you bring the fluid so with the afferent vessel you bring in that dirty lymph that lymph that is filled with bacteria viruses cancer cells all those different pathogens and then you will create an immune response against it and then out of these efferent vessels you find that clean fluid which will then get deposited back into if you're on the left side left lower limb right lower limb left upper body with the deposit in the thoracic duct that ultimately on the right side it will be deposited into the right thoracic duct. So in comes the dirty fluid filled with bacteria, viruses, cancer then you create an immune response against it and hopefully out will come that clean fluid and it moves via the contraction of the skeletal muscle, that milking action. So now we'll take a look at some lymphatic organs.
We talked about the lymphatic vessels. Now we'll talk about those lymphatic organs. So the spleen, right the spleen, so the spleen right here, thymus, tonsils and pyrus patches.
So we'll start off with the spleen. So the spleen is filled up with these guys, kind of look similar to those, those macrophages. If these little white pellets are worn out red blood cells that the macrophages inside the spleen will eat up and devour because you don't want a bunch of dead. red blood cells floating around within your circulation. And we talked about that life cycle of your red blood cells.
They live for about 120 days, four months. So they eat them up. And it can also serve as a little tank, a little blood reservoir. So it's kind of a cleansing area which can clean out your fluid, clean out your blood. And then the thymus.
T-cells are called T-cells because they grow up and mature within the thymus. So the thymus starts with a T. T-cells begin with a T. So we know that all the blood cells, they're born within the bone marrow. But your T cells, they will migrate to the thymus where they kind of go through a process like a police academy, where they'll be trained to become immunocompetent.
They'll become trained to fight specific pathogens. So that police academy is the thymus gland. It will be a site where those T cells will mature.
It's a site of T cell maturation. And they produce a hormone called thymusin. which will help to program and develop those T cells.
Then the tonsils are small military bases within your mouth. So within your mouth it is a whole, it's like the United States of bacteria. It's a world of bacteria which are located within your mouth. You're constantly ingesting foods which could be contaminated so you want to be sure that you could cleanse that area. So your tonsils, they function, they have a lymphatic function in that they can have those lymphatic tissue within them.
And remember, within the lymphatic tissue, you got your B cells, T cells, macrophages, which can help to clean up. So you can develop tonsillitis if you get kind of too many bacteria, which can clog up the lymphatic organs and the very tissue which function to provide the defense gets inflamed. So itis, when we hear that word itis, it's referring to inflammation. So it can become inflamed when you get too many bacteria present and you can mount an immune response against it. And then these Piers patches.
I saw a commercial for a yogurt where Aaron Andrews, the female. sportscast was like you know a good percent of your of your immune system is located within your stomach so your pyres patches right those are kind of lymphatic tissue that is located within your intestines so just like your mouth is a very dirty area your intestines are a area which are where you have a whole bunch of different whole bunch of different bacteria you've got good bacteria which can help with your digestion or those probiotics that can produce you know good substances you know like vitamin k Then you could have some bad bacteria which can cause illness. So the pious patches, they function to get rid of any bacteria that could be lurking within your intestines. Then you have the malt.
Mucosa associated lymphatic tissue. So that includes those pious patches within the intestines, tonsils within the mouth, and pharynx that help to monitor. your mucus membranes.
We talked about those mucus membranes in your respiratory tract, your GI tract. So you have all of these things which are functioning to protect your respiratory and GI tract from infection. So within your body you have innate, your defense system within your body, it can fall under different categories.
You have the innate immunity which is not specific. So view your body as like a medieval castle. Right, you have One barrier against it would be like that wall.
That wall, you can throw a brick at that wall, then it will bounce back. You can throw an arrow at the wall, then it will bounce back. So it's a non-specific defense against any type of bad guy which is trying to hurt it. And then think, behind that wall, you would have little archers. They fight arrows that are specific to maybe a French enemy.
And then you find an area that would be specific for the English or specific for Mongolian. So it's specific for a specific pathogen. So that is how your immune system is set up.
You've got an innate component of the immunity, which can protect against anything kind of in general. So it's not specific. And then you've got the adaptive component, which is specific for a specific type of pathogen. So you'd have a specific response against staph. You'd route a specific response against strep.
specific response against the chickenpox, specific response against the flu. So we'll talk about that innate and specific component. And that immunity, that is that resistance to a disease that you're probably familiar with if you've gotten your vaccinations. So the innate response, remember, that protects against a variety of different invaders, adaptive, it is specific for a specific pathogen. So components of that innate response.
So one major component is the skin and the mucous membranes. Skin, mucous membranes, and also special cells. So your skin. So I talked about that analogy of those troops landing on a beach. So just like some paratroopers land on a beach to try to attack a certain person they're fighting against.
You have these bacteria, these viruses, these pathogens that are landing on your skin. that want to break into your body to colonize it and cause infection so you see that first barrier of first barrier defense we talked about we talked about the skin so the pH of the skin right it is acidic so it is above 7 or below 7 below 7 to inhibit the growth of certain types of bacteria some bacteria like to live in a basic environment so we make our skin acidic so that the bacteria won't grow it's like if you know that somebody likes to live at a temperature that is 90 degrees you make the temperature of your place 70 degrees so that they won't want to live there So same thing with the sebum right is produced from those sebaceous glands that oil which functions to make it inhospitable for bacteria and also the vagina as the vaginal secretions So within the vagina, but it is an acidic environment So you have a bacteria within the vagina called lactobacilli. This is just FYI, I guess. It eats up carbohydrates in the environment. Eats up carbohydrates, sugar.
And then it produces lactic acid. and by doing that it makes the vagina makes it acidic around four or so so some sometimes what can possibly happen when taking a broad spectrum antibiotic right you could kill the good bacteria and then it could lead to make the environment more basic which can make the environment more hospitable for bacteria or yeast which like to live in a more basic So all of these things, the pH of the body serves a defensive function. And then your stomach, it is acidic because your stomach is a big pool of hydrochloric acid as we'll talk about when we talk about the digestive system.
So it can work to dissolve any different types of pathogens that are present and anything that likes to live in a basic environment. So that pool of hydrochloric acid has an immune function and also can help to digest proteins. And then, so saliva.
So saliva and tears. So within the saliva and tears, you have an enzyme called lysozyme. This enzyme, it can help to eat up the cell wall of different types of bacteria.
So bacteria, they have cell walls which surround them and protect them. And within the tears and within the saliva, you can have that enzyme called lysozyme. which can function to eat up and destroy that. And also you have the mucus within your digestive and respiratory tract. So that mucus acts like a fly trap.
So you got a little fly trap that's kind of sticky, and the fly lands into the trap and then it eventually dies. That's supposed to be a fly. So it's dying. So same thing within the respiratory tract and digestive tract.
You got mucus which lines the respiratory tract. It can function to It can function to trap any bacteria or different particles which are present in the environment. And then you have cilia, as we talked about when we talked about the respiratory tract.
So aligning this, you have mucus, which can trap microorganisms. Because we breathe 12 to 15 times a minute, and we're inhaling a whole bunch of different bacterial or viral particles. We don't get respiratory and tract infections all the time because we've got that mucus, which can trap those particles.
those pathogens and we have cilia which can brush which function to to brush them out of the environment so the next line of defense is within this we're still in the innate remember we're still in the innate right that general non-specific response so within the innate you've got your certain cells natural killer cells we'll talk about the inflammatory response different little pacman phagocytes proteins and the after process of fever is a part of the immune response as well. So the natural killer cells, those are certain types of phagocytes which can eat up and attack cancer cells or cells that are multiplying out of control or cells that are infected with a virus. so viruses work they are kind of like a trojan horse i think back in like greek mythology right the trojans were fighting the romans and the trojans were able to or trojan find the greeks whichever one right so the trojans were able to defeat the greeks because they brought them the gift of a horse and within the horse they had a whole bunch of trojan soldiers that were released and destroyed the whole army So that is what those viruses are like. They're like Trojan horses which have the instruction manual for the virus. So they're like bad news in a protein coat.
So a virus is as a protein coat and then within it, it has the instruction manual, which would be a nucleic acid. It could be DNA or RNA. How viruses work, they attack the host cell.
and they deposit their instruction manual into the host cell. So it docks like a spaceship. Then it will deposit its DNA or RNA into the nucleus and then use the cell as a factory machine, like a fax machine, not a fax machine, a copy machine, to create more copies of itself. And then once it's done making those copies, it will then explode out of the host cell and release the whole...
infestation of viral particles which can then go and infect other cells. So virally infected cells they, and we saw that within that first video we saw about the inside of a cell, AMP1 so these cells will then go on to infect other cells so virally infected cells will kind of put up little white flags that say hey I'm infected And then these natural killer cells will go in and attack. Same thing with the qi cells. They will go and attack those virally infected cells in the environment. And they secrete them.
So if you perforate your paper, you put holes within it. So they secrete a toxin called perforin, which will make holes in the virally infected cell and cause them to explode and disintegrate. Then the inflammatory response. The inflammatory response.
It is an important general response against tissue injury, whether it is a bacteria, a virus, whether it is an ingrown hair, whether it is trauma to the body. It is just a general response against tissue injury. So just like.
just like if there is a accident at the school and they call the ambulance and they call the police officer the police officer will rush to the site of injury so your blood cells will rush to the site of injury so your blood vessels they will your blood vessels will dilate just like the streets will open up to let the immune cells get to the site of injury so you get basal dilation facilitated by that histamine that we talked about when we talked about those blood cells. So your blood cells will dilate. And just like that friction, right, that friction of those blood cells zooming across will cause heat.
And then as you see here, these blood cells, the blood vessels will become permeable so that the blood cells can get to the site of entry. But as we know now, the blood has a bunch of fluid in it, that plasma. So that plasma will leak into the tissue and cause swelling.
will cause swelling and then you get pain as a part of the inflammatory response because the body produces these pain producing chemicals which signal that say hey there's something bad going on because pain is your body ringing the alarm and saying that something bad is going on within the environment. So I'll show a video which will describe the different steps in the inflammatory response. So what inflammation does is, so it makes sure that those damaging agents which may be causing infection, they get taken care of.
So you see this phagocyte eating up the bacteria. So they help to eat up any bacterial particle which could be present and set up the next agent when you get that repair process, which you guys described in AMP1. So just review those steps.
So these white blood cells, right, these neutrophils, right, they travel through the blood vessel just like this fireman is walking. These are able to go through the blood vessels because these vessels have been dilated and they're able to get through the blood vessel because they are permeable. So they're able to squeeze through the blood vessel in a process called diapedesis.
Diapedesis. So they're peddling to this side of injury. So then these do that chemotaxis. Remember, your damaged tissue, it releases these chemicals which attract the neutrophils just like perfume can attract the... that skunk to the side of entry.
So it attracts them to that side of entry, so that positive chemotaxis. And then you have phagocytosis, which is that last component. This is where those white blood cells, those neutrophils, can eat up any damaged particle which would be present in the environment.
So make sure you can, in short answer form, describe the process of inflammation. You can get the vasodilation, the blood vessels dilate. get vascular permeability.
The blood vessels become permeable to allow the white blood cells to get to the site of injury. And then through diapedesis, the white blood cells move from the blood vessel to the site of injury. And then through chemotaxis, they get further attracted to the site of injury and then they attack the damaging particle through phagocytosis and you get the redness because all the white blood cells are rushing to the site of injury. You get the swelling because all of that fluid is accumulating from the plasma is leaking into the site of injury.
You get heat because the movement of those white blood cells across your blood vessels and you get pain because your body is producing pain causing chemicals. So this shows the process of phagocytosis, engulfing. So somebody has dysphagia, right? They're not able to eat. that is a stroke in the area where the muscles that facilitate eating.
So, phagia, referring to eating. Phagocytosis, cell eating, engulfing those different microbes just like you would engage, eat your food. So, within the phagocyte, you'd have lysozymes which help to digest the food within the phagocyte. So, the... The phagocyte would eat the pathogen and engulf it forming a phagosome, this lysosome.
would join up with it, deteriorate what it ate, and then it would just digest it, and then out would come the digestible particles. So maybe this is a bacteria that has been consumed like the pebbles that Pac-Man eats. So antimicrobial proteins, and they play an important role in the defensive function of the bodies. Two of them are complement, which can act like a landmine.
And also interferon, which is kind of like your body's alert against viruses. So first I'll talk about complement. So complement, so those are kind of a group of 20 different proteins which are within the plasma, the liquid portion of your blood.
And they're produced within the liver. What they can do is they can facilitate that vasodilation. And they can also cause this process called opsonization where they can land onto the whole cell.
And then they could cause pores to open up and then it will cause the cell to blow up and explode. So it's like a little land mine which lands on the surface of the pathogen causing it to explode. And then interferon. So I talked about how the viruses work by infecting the host cell. So this would be the host.
So what if this host cell, let's say this is in the respiratory tract. So let's say this host cell is going to do its neighboring cell a favor. It's going to say, neighboring cell, you need to put your defenses up because there's a virus on the loose.
So what this cell will do, it will produce this interferon. Interferon, it will be released from that virally infected host cell. And then it will kind of give the signal to the neighboring cell to put its defenses up. so that it would be kind of protected against so the virus would not be able to infect it so that it is kind of an alert that a virally infected cell puts up so that the neighboring cell would not get infected by a virus.
So it's the natural antiviral your body produces. Think IV. Think IV.
Interferon for viruses. And then fever. So we see fever. See that crackling? fire so that is that abnormally high body temperature so i talked about how your body can make your skin acidic because certain bacteria like to be live in a basic environment same thing with your body temperature so it's like if you have an unwanted house guest right while they're asleep you turn the temperature up to maybe 90 degrees so they start sweating and then they want to leave your house so same thing with the bacteria so bacteria and virus they like to live within a certain temperature So if you turn the thermostat up within your own body, it makes it a little bit inhospitable for those viruses, for those bacteria, so they won't want to live there anymore.
So that is what we do with the virus, with fever. We turn up the heat within our bodies so that those pathogens will not like to live in the environment. And it can also help to speed up the immune response and also help to speed up the process of tissue repair.
And we talked about how the hypothalamus... is the body's thermostat. And also, it helps the binding of iron and zinc because microorganisms, a lot of microorganisms like to use the iron and zinc that we have. So high temperatures help to bind up the iron and zinc and say, no, you can't have it. Bacteria, we're going to keep it.
So in order to create that, inflammate that fever, Your body releases these pyrogens, right? Your white blood cells will release a pyrogen, which will stimulate the hypothalamus to increase its temperature. So now we'll get to the adaptive response. So it's like that archer who has an arrow that is zipped specific for whatever type of whatever they are trying to hunt.
So you have that third line of defense of the immune system, which is specific. for whatever type of pathogen is attacking you. If you have the flu, you create antibodies that are specific for the flu. You have T cells which will specifically attack the flu. You have the cold, you produce antibodies specific for the cold.
You have T cells which will specifically attack the cold. So you have different aspects of the of the immune risk of the adaptive immune response one is antigen specific so antigens those are substances on the surface of different pathogens that your body can recognize and create an immune response against so view it like a id card that these bacteria, viruses that these pathogens have that your body can then recognize and then create an immune response against. So it is specific for an antigen. So it can recognize an antigen on the flu.
So the flu is also called H1N1. The H and the N, those are particles on the surface of the flu that are antigens. So we see the flu, it can have. one little protein sticking out is the H, one little protein sticking out is the N.
Then your body can then recognize that pathogen, that antigen, and create a response against. And then the immune system is systemic, meaning that it happens all across the body. It's not just restricted to the site of infection and memory, right? That little floppy disk on your Microsoft Word that allows you to save your document or save as.
So memory, right, you get the infection, you get the flu, and then your body creates an immune response, and it also creates cells which will remember what that flu looks like. So the next time you encounter that same strain of the flu, your body will make a quick immune response which will then attack it. So it's like, fool me once, shame on me.
Fool me twice, shame on you. Because your body will remember what that flu virus or whatever microbe it is, but remember what it looks like so that the next time you encounter it, You will make a quick rapid response against it. So you have two components of that immunity. So humoral immunity refers to the action of your B cells producing those plasma cells releasing antibodies.
So this shows a B cell releasing these Y like structures, these antibodies. So this is showing humoral immunity. So think HB, humoral immunity. Humoral immunity refers to...
B cells turn into plasma cells releasing antibodies. So it refers to the acting of those antibodies. So little ninja stars that your body releases in response to a pathogen. So antibodies.
So humoral immunity refers to the antibodies. Cellular immunity, think CT. Think CT. Cellular immunity refers to the action of your T cells.
Your T cells. So this we see right here. We see a T cell. Then maybe this is a virally infected cell. We'll see it.
Attack it. Boom. cause it to explode so cell mediated immunity refers to the act of c cell t cells reacting against either viruses cancer cells or cells from a graft so we'll talk about the different components of the the cellular immunity humoral immunity and cell mediated immunity so those antigens non-self so we talked about those antigens that are on the surface of your red blood cells which can say hello i'm type a i'm type b so this is the type A antigen. But you can find those antigens on the surface of microbes. So you have a bacteria, and maybe this would be an antigen, a little antigen on its surface.
Or we have a virus, and you have the H and the N, which are examples of antigens that your body can then recognize, and then mount an immune response, and then mount an immune response again. So maybe those are carbohydrates on the surface of that bacteria. different types of proteins.
Pollen can be considered an allergen because that allergic response is your body creating an immune response against something that is innocuous, that really won't cause any, that really isn't that bad. So any substance, so make sure you know what an antigen is, any substance provoking an immune response. So antigen means antibody generating. So self-antigens, so those are a few. Those are little ID cards on the surface of your own body.
So on your red blood cells, you've got the ID card that says, yes, I'm type A, I'm type B. You have spleen. You've got all of these antigens that are surface of your tissues, which let them know that it belongs to you. Because your body will be patrolling, looking to see if any bad guys are present.
So your body has these antigens, which will recognize that you are self. So I'm not going to create a response against you. However.
We'll talk about autoimmune disease where the body cannot distinguish between self and non-self and then your immune system will attack itself. So, yeah, so this is an example would be those blood transfusions, right? If somebody type type B blood gets the wrong type B blood gets the wrong type of blood, they will mount an immune response against it because the body is like a family reunion that does not want other people located within it. So allergies.
Allergies. Those are, I kind of gave that analogy before where if somebody's knocking on your door. some cookies many person in the face it is L it is an exaggerated response to something that is not causing you any harm so those allergies but those are an exaggerated immune response to something that your body should not reach not be creating an immune response against those those small molecules pollen pollen is an example type of type of allergy you could you can attack your own self as well as we saw with multiple sclerosis as we talked about when we talked about the nervous system. So now we'll talk about that, the actual action of your B cells and your T cells.
So in order for them to function, they first need to become immunocompetent. They need to be trained. You don't want police officers, untrained police officers roaming the streets.
You don't want untrained immune cells within your within your body. So the immune cells, first, as we know, they grow and develop within the bone marrow. And then that immunocompetence, that is when they learn to recognize and learn to recognize the bad guys. So we see, first, those lymphocytes, they grow and develop within the red bone marrow. However, the B cells, they will...
become immunocompetent within the within the bone marrow. That's why they're called B cells because they grow up and develop within the bone marrow. G cells, they will migrate to the thymus where they become immunocompetent. The process of immunocompetence is kind of like within a when they're doing that police training. They show up a picture of a maybe a grocery store owner and then a cop is not supposed to shoot that picture.
However, they show a picture of a guy having a knife and then they will they're supposed to shoot that picture so the immunocompetence they're trained to recognize those non-self antigens they're trained to recognize the bad guys and not to attack the good guys within the body so once they have been trained to recognize the bad guys they will they will be programmed and then they will live within the within the lymph nodes And then once they become activated when a specific pathogen enters the body. So let's say we have a T cell which is kind of programmed to attack the flu. It's programmed, but it's not activated yet.
It will become activated when it gets exposed to the flu. And then you get a whole bunch of T cells which will attack against the flu. You get a whole bunch of B cells which will have antibodies which will produce the flu. which is anybody's against the flu so first they grow up and develop the red bone marrow become immunocompetent and then they will become activated and circulate within the circulate within the the bloodstream so we talked about those macrophages which are the, which can secrete, they're those pac-men within the spleen, liver, and throughout the body, and they also secrete different signals.
They secrete substances called cytokines. Those cytokines can work as kind of communication signals, which can stimulate immune cells to multiply, grow, and develop, or to attack certain pathogens. So we talked about that specific immune response. So on your B cells, we'll talk about the humoral immune response, which refers to the action of your B cells. So on your B cells, we see a B cell here.
On this B cell, it has a receptor, and it will bind to a specific antigen. So let's say this is a piece of the flu right here. It will bind onto that B cell, and it will become activated. Then that B cell, it will develop into a plasma cell, which will release antibodies right here.
And then the amazing part of the immune response is that you create memory. Those B cells will remember what that specific strain of the flu looked like. So this would be a memory cell, which will grow and develop. So upon next exposure, your body will quickly produce a whole bunch of antibodies.
So they'll produce and also they'll multiply. They'll produce clones and copies of themselves. So it's kind of like somebody is attacking...
You're able to make more copies of yourself so that you can attack the bully or whoever is attacking you. So this shows the B cell releasing those antibodies. So I'll go over the humoral response again.
So you'd see a...so this would represent... This would represent a B cell. Let's see right here. This would be a B cell right here.
And then this is the B cell receptor. On the surface of the... That's kind of messed up.
B cell receptor. So then it would recognize... First it would recognize an androgen. Let's say this is a piece of the flu.
Then it would produce a whole bunch of... plasma cells and then those plasma cells would do a process of clonal expansion where they would multiply and multiply to create more and more and more and more of the cells and then they would release antibodies which are specific for the flu that you saw. So those B cells turn into plasma cells and antibodies and then The B cell would also turn into memory B cells that would remember what this guy looks like.
So the next time he comes around, the B cells will make that quick response to it. And then so the different types of immunity. So the active immunity. that refers to when you...
so this would be a B cell that refers to when you... this would be a B cell so you introduce an antigen to that B cell and then it turns into a plasma cell and then releases antibodies releases those antibodies so it is actively producing those... antibodies. So for example, when you, so this would be somebody sneezes on you, you get the flu, your B-cell recognizes it and actually produces antibodies against the flu. An artificial type of active immunity would be, let's say this is the flu vaccine.
So they give you a dead weakened form of the flu, your body recognizes it, the B-cell recognizes it, and then actively produces those antibodies. Then the passive immunity That is when, let's say this is you. This is abstract. This is you.
This is a person. That refers to when the antibodies are just given to that person. So instead of actively producing those antibodies, they were just saying, hey, we're just going to give you those antibodies. don't actually produce me doesn't give you those anybody so let's say from mother to a child that's called nationally acquired passive immunity think now think babies take naps that nationally acquired passive so the mother's breast milk she nationally gives those antibodies to her child or you can have a type of immunity where let's say you have a when you get rabies I you want to quickly give that person antibodies to rabies don't have time for them to produce those antibodies against us so we will give them those antibodies or anthrax so within your within your serum so within James'serum he has antibodies for anthrax because he got that initial vaccine to it so within his serum he has antibodies so somebody gets exposed to anthrax they will take just those antibodies and give them to the person because they just want to quickly give it to them don't have time for them to produce it naturally.
So they're considered those borrowed antibodies. So you have different classes of antibodies. So they're Y shaped. They kind of look like these Y's.
They kind of look like these Y shaped structures. Right here. So we have...
So these, they're called, they call these portions the light chain. These right here are the heavy chains made up of amino acids. Remember, antibodies are made from proteins, right?
Those are examples of proteins. We see the importance of protein within the diet. In order to create those antibodies, you need to consume the protein. So if somebody is protein deficient, then they won't be able to produce those antibodies that their body needs. So you have these different classes of antibodies.
So think MAG, MAG or GAMED, whichever abbreviation you'd like to use. So the MAG. So M, think M for complement. Think M for complement.
They play a role in binding onto that complement. I think M for complement. I think M for complement.
So IgM immunoglobulin M. So M for complement. IgA... IgM...
Com... Let's see. So they play a role in complement.
IgA, think slime A. Think IgA, think slime A. Because they are found within mucus.
So the slimy mucus, you find that IgA within your mucus membranes. You find that IgA. Then IgD, think B and D.
Think Dave and Busters. So IGD is a receptor on the surface of B cells. So IGD is on the surface of receptor on the surface of B cells.
So Lindsey, your hand was an example of IGD because it was a B cell receptor. So IGD. IG, IGD, think D and D.
So the surface of B cells. So IGG. So IGG, think GAGA.
Because that is when that passes over the placental barrier. So it passes through the placenta going from mother to child. And it's also the most abundant.
So it is think general. Think IgG for general as well. General because it is the most abundant antibody. So think G for GAGA because it plasters the placenta in a pregnant woman to provide that baby's growing immune system with antibodies. And it also is in general.
And then IgE, think allergy. IgE, think allergy. IgE plays a role in the allergic response. So we talked about those. We talked about those basophils and also cells called mast cells which they have IgE on their surface and their little pinatas filled with histamine.
So when a pollen granule binds onto that IgE on the surface of that basophil or mast cell it will boom, explode and let out an explosion of histamine. So IgM, think complement. IgA, think slime A, you find it with your mucus membranes.
IgD. Think D and B, you find it on the receptor on the surface of your B cells. IgG, think general, is the most abundant.
And it's also found within the process of the placenta barrier. And IgE for allergy. So those functions of those antibodies, so they can neutralize.
So different bacteria release different toxins, and those toxins can cause a variety of damaging effects to the body. So the... antibodies they can surround the bacteria and prevent it from releasing those damaging toxins and it can kind of surround and neutralize other microorganisms as well. It could cause you know clumping right so if you have the wrong type of blood you could create an immune response against that type of blood cell and it can also work to facilitate the binding of complement. See that so this is the IgM on the surface, binding onto that complement, letting that big hole develop within the cell that will act like a lamb mind.
And it can act like steak sauce in a way. It can make it easier for those phagocytes to eat up the bacteria. So we see a bacteria that has those complement which makes it easier for the immune cells to eat them up. Kind of marks them for destruction. Now, this also facilitates the release of histamine.
So we see this is showing maybe a basal fill or a mast cell that has... IgE bound onto it and it binds onto it. This yellow red dot is an allergen. It binds onto it and causes poof, an explosion of histamine. So all these things are facilitated by those antibodies.
So now we talk about the humoral response, which refers to the action of those B cells turning into plasma cells, releasing those antibodies, the action of those antibodies. Now we'll talk about the cell mediated response. So think CT. Cell mediated refers to the action of those T cells which functions to fight against viruses, fight against cancer, fight against grafts.
And those T cells, they are like a basketball player that only can dunk if he or she gets an alley-oop from another player. They need to have antigens presented to them in order for them to be activated, in order for them to function. So... this shows a macrophage that has engulfed, let's say it has engulfed a viral particle. It will then kind of spit it out and present it to a T cell.
So a certain type of cell, T cell called the T helper cell. That T helper cell will then go and activate different B cells. Let's say B cells, you create some antibodies that will attack this virus. And then it will then signal to these killer cells.
Killer cells, you go and attack. cells that are infected with this virus. So first it needs to have the antigen presented to it by an antigen presenting cell.
So an example of antigen presenting cells are those macrophages which will then eat it up and then eat it and then present it to a T cell and then the T cell will then go ahead and do its job. So the different types of T cells. So we have cytotoxic T cells. Those are the T cells that do the killing.
So this shows a cytotoxic T cell. This maybe is a cell infected with a virus. That T cell will recognize once it has been presented, once the antigen has been presented to it and has been activated, that T cell will then go and attack a virally infected cell and secrete that perforin, which will perforate the cell and cause holes to develop and cause it to explode. Then you have the T helper cells.
The T helper cells they play a role in activating those killer cells and they also help to activate B cells. So the T helper cells they have two functions. They can activate the killer cells. So say they don't do the killing themselves.
What they do is they stimulate the killer cells to go and attack. And they stimulate the B cells to go and produce anybody. So you see if.
You're deficient in those T helper cells. It will be like a football team without a quarterback, a basketball team without its point guard. So that's what occurs with HIV, and we'll show a video that will describe how HIV infects those T helper cells.
So you kill the cells, which would usually be used to kill the virus. So the T helper cells, they die. T cell count drops, and you can develop infections. They're called opportunistic infections. So just like if your shields are down, then your enemy will take advantage of that.
If your immune system is down, then you can have different types of microorganisms which can grow and cause opportunistic infections. So this shows just the action of those cytotoxic T cells. They see it, they attack it, release that perforin, cause them to explode. You also have different types of T cells.
So those T cells, they will do that same process. They will multiply themselves to create more themselves and they'll also have memory. They'll also have memory T cells which will remember what that pathogen looks like, whether it is the flu, chickenpox, whatever it is.
Remember what it looks like so the next time it will make a rapid, quick response to it. Then you have T regulatory cells which can kind of tell those T and B cells to kind of calm down and make sure that immune response doesn't get out of control. So this image gives a good overview of the immune, of the humoral and the cell mediated response. So the EAT antigen is introduced to that B cell. B cell can then create plasma cells which will multiply and create a whole bunch of different antibodies.
Or it can develop memory cells which will click that floppy disk and remember what it looks like. and then the humoral immune response. So the macrophage engulfs whatever the antigen is and then presents it to a...
to either the killer cell or the helper cell. So it presents to the helper cell, right, this helper cell, it will develop into a memory T cell, and it can also go on to activate, it can also go on to activate the B cells. It can, that helper cell can also go on to activate the T cells.
So the, and then going, restarting to see how those killer T cells work. The antigen is engulfed, and then it can. stimulate those T cells to then go create memory T cells and then go multiply and go create more killer T cells, which will then go and attack whatever virus or pathogen is present in the environment. So graphs, so we talked about how your body is like a family reunion that doesn't know what any other organisms within it. So you can have different types of graphs.
So we saw in the beginning, we saw the skin, how maybe if somebody has a burn that they do a skin graft and replace that skin with skin from their own body so that is an example of an autograft you get a burn you take skin from your own body and transplant it to the other part so isografts those are if you have identical twins so identical twins so allografts allografts would be from an unrelated person, so allograft unrelated, so if isograft was maybe was, if this was, in fact, you know, full house maybe isograft was maybe the Olson twins right, they got an isograft, maybe one of them needed a kidney or something like that and then allograft, maybe the neighbor maybe Kimmy Gibbler donated her kidney to one of the the twins, allografts. So xenografts, that is taken from another species. So we talked about how we can have heart defects. Sometimes they use heart valves from other organisms to do grafts.
So think xeno is like a zoo. A zoo xenograft, you take a graft from another type of animal, different animal species. So allergies.
So allergies. So this shows how that allergic response occurs. So let's see, we'll go back. So those are called hypersensitivity. So if somebody is hypersensitive, they're very sensitive, you tap them on their shoulder, then they make like a quick response.
So same thing, that is a quick immune response to something that your body really should not make an immune response against. So hypersensitivity is just another word for hypersensitivity. and allergy. So we'll go through the steps in the development of the hypersensitivity. So there's kind of a two-step process.
So first, the antigen, let's say this is pollen. This little piece of pollen will be presented to a B cell which will turn into a plasma cell which will release that IgE antibody. Right here.
Then, the antigen will be released That IgE will bind onto a mast cell or a basal fill. Mast cells or a basal fill. So that the fly, the trap is set.
So it's like you have a rat trap. The rat trap is set. So now, right so the next time that allergen invades the body, it will then bind onto the IgG on the surface of that basal filler mast cell and then poof.
you get a big explosion of histamine. And as we talked about, the histamine causes vasodilation, vascular permeability, which causes all that fluid to go into the cap, go into the organ. It gets overstimulation of mucus because your body produces mucus as a trap for different pathogens. So too much of that mucus. And then you can get constriction of those bronchioles.
But... sometimes for allergic response they give the person an epi pen. So the epinephrine will bind on to what receptor on the surface of the bronchioles?
Theta. And then you get dilation of those bronchioles. And that anaphylactic shock, that is systemic, systemic, all around the systemic, that reaction occurs all across the body. So delayed hypersensitivity, that is when, for example, your tuberculosis shot, you get... You get the TB test and then after a while your body creates that immune response against it.
So it kind of takes a while for your body to develop an immune response against it. So the TB test is an example of a... It takes a while for your body to create an immune response against that, the antigen that was introduced to the body.
So autoimmune disease. So that is when your body attacks its immunodeficiency source. We'll start with immunodeficiencies. That is when your immune system is weakened. Your immune system is weakened.
You could either be born with it or, so congenital meaning that you're born with it. So an example would be like the bubble boy disease where the person was born with, they were deficient in both B cells and T cells and had nearly no immune system. So they were born that way.
Then they could be acquired. An example would be AIDS. That means acquired immunodeficiency syndrome.
So that virus, what the virus does is, so let's say this is a T helper cell. So this is the HIV, HIV virus. It will then invade a T helper cell.
They're also called CD4. So I think you ask for help. So CD4, the helper cell. So it infects it.
It uses the cell as a copy machine and then boom, explodes, releases a whole bunch of viral particles, thus killing the T cells. So your body will be just open season for other microorganisms to come in and cause different types of infection. And I'll show a video which will describe what occurs in HIV and AIDS. And then autoimmune disease, when your body attacks itself.
So some examples would be multiple sclerosis, which we talked about and which you guys, you all. you all understood was when the body attacks that myelin sheath on the surface of those axons. So you're no longer able to send and receive those different signals as well. And then myasthenia gravis, that is when those, so we have the neuromuscular junction. Acetylcholine is released.
So this is ACH. Acetylcholine is released. Binds onto its receptor.
released binds onto its receptor and you get contraction of the muscle. But what if you had antibodies that were against that, that were against the acetylcholine receptor? You would not get contraction of the muscle so you get, you get see it can't bind, you can't get contraction of the muscle so you can get weakness of the muscle's impairment.
of movement and we saw in the beginning, we saw in AP1 the video of that young woman who was not able to speak properly because she had myasthenia gravis, her muscles were not able to contract because she had receptors were blocked on her, those acetylcholine receptors were blocked. So diabetes, type 1 diabetes, that is when the pancreas is being attacked. They call that juvenile onset diabetes.
see the onset of it during the early teenage early teenage years so those beta cells usually produce so the blood sugar is high insulin is released by those beta cells i think big beta insulin glucagon those beta cells release the insulin which will then decrease the the blood sugar but in type 1 diabetes your body is attacking those beta cells so The blood sugar will be high because insulin is like the doorbell. It's like the person that rings on the doorbell. It rings on the doorbell to let glucose get into the cell.
But without the insulin, the door doesn't open. You get a whole bunch of glucose within the blood, as we talked about a few times already. Then rheumatoid arthritis, when we talked about the joints, we saw that image of the woman who had her joints were kind of disfigured. because her body was attacking her own joints. So the arth referring to the joints, itis referring to inflammation.
And then glomerulonephritis, that is often when people get, that is a result of maybe untreated strep throat. So your body, so you get the streptococcus, which causes the strep throat, and then the body produces antibodies. So this would be the glomerulus. The glomerulus is a ball of capillaries in the kidney which filters out blood.
We'll talk about this when we go over the renal system. So this little glomerulus is a ball of capillaries in the kidneys which filters blood. So somebody gets a strep infection.
So this would be the strep. Your body produces antibodies against that strep. Those antibodies will then go and attack the glomerulus of the kidney, causing inflammation within the glomerulus, causing glomerulonephritis. So strep antibodies.
attack the kidneys. And then lupus, right, that is an autoimmune disease that is systemic. It occurs throughout the body. It can affect the kidneys, heart, lungs. You can see that butterfly rash.
A rash that kind of looks like a butterfly is one of the main symptoms of lupus. So it's systemic lupus. The erythematous, remember the ery, those erythrocytes.
So red, you see that red rash, right, so red rash, that erythematous rash along the surface. A butterfly rash along the surface of the face can affect a wide variety of different organs in the body. And we'll see some videos which will describe that. Another type of disorder is rheumatic fever.
That is kind of similar to glomerulonephritis. That is when you get a strep infection that maybe has gone untreated. So this is strep.
This is strep. Your body produces antibodies against the strep which can then damage the valves within the heart. Not a lot is known about how these autoimmune disease develop. How these autoimmune disease develop. It's just that your body is not discriminating between self and non-self.
So I'll show a few videos which will describe some immunodeficiencies and immune disorders.