this picture looks a little bit overwhelming but this is showing the steps of the inflammation response so just keep in mind I mean how tiny this is that looks like a giant stabbing weapon of some kind that's just a splinter so a splinter is gonna break through that epidermis which remember the top layer of your skin is pretty much dead and so it's there for protection that's supposed to slough off every day so if you've betrayed that now things have entered your body so this picture is showing all that bacteria in there so the damaged tissue begins to release histamine which causes swelling this is why we take antihistamines right is to get rid of our itchy watery eyes during allergy season so the histamine causes the capillaries to get a little leak year so normally those fenestrations are there those pores are there we'll now they get a little bigger so that way the white blood cells those phagocytes can get out there and gobble up all the bad stuff the platelets will also move out of the capillary to help seal off that wound I feel like we've mentioned the inflammatory response a lot but it is pretty crucial this is a nonspecific immunity defense because again we don't really care what's getting in there we just don't want it in there so whether you got some poison from the plant that stabbed you or if you got some bacteria we don't care we just want to keep it all out so the inflammatory response does a lot of things it helps to dilute those harmful substances so by releasing a lot of water and other things from the capillary bed it dilutes like if that plant was poisonous we're also allowing better oxygen exchange and nutrients to get sent to the site of injury so we can repair the tissue we send out those clotting factors and those white blood cells we also just simply let the body know something's wrong when something is inflamed on your body and kind of throbbing and achy yeah sucks but at least lets you know that something's going wrong also helps to wall off and isolate the area because whatever has now entered our body we want to make sure that it doesn't have a free pass to the entire thing so the four signs redness heat swelling and pain all of this is caused by chemicals that we call the inflammatory chemicals histamine which again is what causes kind of the itchy watery eyes and swelling kinds which dilate your blood vessels to allow more stuff to exit the blood system and complement which we'll talk about on another slide the inflammatory response process begins with the macrophages showing up and realizing they've got a lot of stuff to gobble up so they send out some chemicals other chemicals are involved like the kind needs which we just mentioned the prostaglandins which we mentioned when we did the endocrine system remember aspirins shuts off your prostaglandins so that kind of initiates the inflammation response histamines causing swelling and complement basically again we're gonna have a slide that talks about complement basically complement is just a whole bunch of chemicals that help your immune system so they call it complement because it complements the immune system so all of this results in your vessels dilate letting all that stuff go but that results in redness because the blood is rushing to that area and intense heat the heat is purposeful bacteria for the most part like it at 98.6 so if you have an injury like an infected nail or hangnail or something if you make that area really really warm temporarily the bacteria sometimes can't reproduce or it may even kill them we want to increase the permeability of those capillaries we want to let fluid go which is called exudate you don't have to know that term but when we send that fluid out which is mostly water it's gonna have those clotting factors it's gonna have antibodies we're trying to fight and and kind of heal that injury but that causes edema which is swelling well edema causes pain because you have all of that fluid pushing on your nerves so the problem is people try to treat inflammation when really unless it's just completely unbearable we should let it go because it's a sign your immune system is doing what it needs to do your body makes a ton of antimicrobial chemicals so a cytokine is any defense chemical so you don't really need that term because it's pretty generic lysozymes are chemicals that are in your tears we saw those when we talked about the lacrimal system remember these are a genius chemical because it attacks cell walls and so it's not gonna harm your tissue so this is great interleukins there's 26 different kinds of those we don't have to know details other than this just helps white blood cells communicate so I think of it like when you're at an accident site and the cops use their radios it just helps them communicate better interferons this is the only one we have against viruses which we will deal with on another slide but the key with interferons just think viruses basically it's gonna interfere with the viral life cycle chemokines encourage white blood cell migration to the infection I think of this like a flare you get into a car accident you send up a flare which means you need help tumor necrosis factors a tumor is just a bunch of cells that have started dividing out of control necrosis means death so you actually have chemicals that help kill tumor cells when some of your cells start going through mitosis a little wildly you're able to kill some of those perforin I think when something's perforated like a piece of paper has little holes in it when it's perforated this is a chemical that's made by the cytotoxic T cells which we're gonna address later on it basically inserts a pore into the target cell so it kind of like stabs them to death which i think is kind of ambitious and so this is a chemical made by what we call our natural killer cells saline solution your skin is very salty right well salt remember kind of sucks out water so the fact that your skin is really salty keeps a lot of bacteria from being able to establish themselves because it would dehydrate them and then hydrochloric acid the acid in your stomach helps with digestion certainly which will have that chapter but it's also chewing up a lot of your gunk you can spend a whole semester on the immune system and thank goodness we're not going to so four complement all I want you to know is they complement your other defenses because it's made up of 20 different proteins that are in your blood plasma and they do all kinds of different things excuse me they can kill cells by destroying cell membranes they can help the phagocytes show up to fight fight they can promote foreign cell lysis so encourage foreign cells to basically explode so they do tons of stuff but again for complement we're just thinking these are proteins that complement your body's other defenses kind of like if I showed up at a war zone and made sandwiches I'm not actually fighting the fight but I'm helping the fight viruses viruses are a huge problem for us viruses are not alive so we can't use antibiotics because antibiotics are anti life so when you get sick with a virus usually just kind of screwed that cold virus that I'm still kind of getting over after three weeks they basically say okay get rest drink fluids yeah who's got the time for that so a virus is just a piece of DNA or RNA that's in a protein coat they're very tiny and it's very hard for our body to recognize these as bad because our whole body is protein based so when we see this thing enter our body and it has proteins on it we don't normally recognize it as the enemy so when a virus infects a cell the cell cannot save itself that cell is doomed so the only thing it can do is kind of take one for the team and it can kind of warn all of the other cells that are around it so basically it gives off this chemical interferon to say I've been infected almost like a flare this tells all of the other nearby cells to get their viral distant defenses up is this gonna save every other cell no it's kind of like during a hurricane when you board up your house is that gonna protect your house no not necessarily your house may get completely leveled but you'd be a fool if you didn't try so it basically tells the other cells there's a virus in the area you need to do your best to not get infected is it gonna protect them maybe maybe not but it's better than doing nothing so interferons interfere with viral multiplication so little picture here is on the next slide so this is showing if you look on the left at the top the virus is injecting the cell with its piece of viral DNA the problem is this gets infiltrated into our DNA and when we go to read the DNA when we go to do transcription and translation we don't realize that that piece of DNA isn't supposed to be there so viruses basically trick us into reading their DNA for them and making their parts for them it's pretty genius so this picture here is showing on the left that this this molecule or sorry this this cell has realized it's been infected by a virus so it releases interferon molecules basically saying guess what guys I've been infected so you can see on the bottom picture there the interferon is docking with the cell next door basically saying okay you better do everything you can to try to block that viral DNA because it's coming for you so it's just again like putting pic or putting on plywood on windows during a hurricane it may save your windows it may not but this is about all we can do against viruses is hopefully up our defense the third line of defense is what we call specific defense so this is when you're actually acting on specific antigens so this isn't like putting up a wall to say nope I don't want rabbits in my yard or deer or my neighbor's dogs this is putting up a specific defense like you lay you set out an ant trap for a particular kind of ant so these involve your lymphocytes so remember your lymphocytes from lab those are the angels of our immune system so this is a very specific type of white blood cell that makes your antibodies we're making these antibodies which are also called immunoglobulins I just called them antibodies we make these from our b-cells which we will see against foreign antigens so antigens are things that are on all of our cells as well but in this case we're referring to the ones that are on foreign cells like pollen microbes like bacteria venom a transplant an organ from a stranger danger these will cause your body to react to make antibodies we've already done this in lab but it's been a while where we looked at all of the different types of leukocytes so leukocytes is a generic term for white blood cells they're all phagocytes and they're named for the stain so that's why their names are kind of strange so remember basophils we didn't have to ID those we could only see those on pictures release histamine so those are very common during an allergy attack neutrophils those we identified by having three to five lobes definitely the most abundant these guys show up when your skin is injured remember puffs I love the word plus is a bunch of just dead neutrophils basically neutrophils that just gobbled themselves to death which I I kind of respect asana fills attack parasites so these guys are usually high in your bloodstream when you have a parasitic worm but it can be also asthma or hay fever and monocytes become macrophages so those guys have the kidney bean on the inside and they can eat things five to six times their size which again I admire I would love to see a glass of wine or a pizza five times my size I know I wouldn't be able to manage it but I would have a really good time trying the fifth one are the lymphocytes so remember those guys are the angels of our immune system because this is what gives us true immunity so we'll focus on this one a lot more there are three different classes of lymphocytes you have number one the natural killer cells destroying a Broadway range of foreign or infected cells you have the B cells which I tried to highlight here B cells come from your bone marrow and they become antibodies so that's a lot of bees there which kind of help us remember it and then t-cells I should have highlighted the tea for finest so natural killers B cells that come from your bone marrow and T cells that come from the thymus these are our three lymphocytes where do these cells all come from well they come from the stem cells in our bone marrow which we saw before so when we looked at it before we were looking at the erythrocytes that get rid of their nuclei these guys keep their nuclei so they start in the bone marrow and then they either migrate to the thymus gland and become T cells so T and T there or they become they go to the bone marrow for B for bone and go become B cells so T cells become from the thymus B cells come from the bone marrow so they go to both of these locations to become immuno competent basically what that means is they have to learn who the home team is they have to learn all of the antigens in your body so they know how to react to enemy cells once they've gotten educated they circulate in the blood and in the lymphatic so I was trying to be clever so we have lymphocytes here B cells bone-marrow antibodies so if we look at this little picture here it's showing the B cells on one side and the T cells on another so when you get exposed to an antigen which is the little pink box your B cells get activated so you can see the little antibodies on the surface of that B cell so he fights that antigen and then becomes plasma cells which are just going to churn out that antibody to protect you from getting that exact same infection again and we also want to create B memory cells and these hang out so that way in case you ever see that and that particular antigen again you'll be ready to fight it you won't have to take the time most the time when you get sick you have that window where you feel like ass on a cracker because you have to make antibodies so once you've made memory cells you won't have that ass on a cracker face you'll have a weapon that's ready to attack the t-lymphocytes again thymus gland which is why they're called this go to your they leave your bone marrow after they're developed they go to the thymus gland so they can learn your antigens we got a no self from non-self otherwise how do we know who to fight we saw this guy before when we were talking about the endocrine system remember the thymus gland is so weird because it's one that actually gets smaller as you get bigger and that hardly ever happens but if you don't mature your immune system you're going to be dead so there's no point in maturing an immune system when you're near 20s because if you didn't already have a working immune system some disease would have taken you out there are two types of t-cells cd4 and cd8 and their names are kind of stupid because their name for a molecule that's on their surface so cd4 cells are not killer cells these guys are gonna recognize your cells specific immune cells that are presenting foreign antigens so I know that doesn't make any sense so on my next slide I tried to draw which when I draw on PowerPoint it doesn't usually end well so this is showing the cd4 cells in action so if you look at the top left there it looks like a cloud oh yes drawing on PowerPoint so this is a macrophage so this is an aggressive phagocyte he's cruising around your body he's gobbling up bacteria he's gobbling up viruses he's gobbling up bits of dead cells this is a good guy so when he encounters a bacteria we want to gobble him through phagocytosis which is the next picture there but we want to be prepared in case we see this bacteria again because what are the odds that you would just have one bacteria in your body chances are if one of these macrophages finds a bacteria there's a whole lot more where that came from so I want this macrophage to let the body know that this bacteria is inside so what he does is he eats the bacteria and then he puts the bacteria's antigens on his surface this would be like you eating McDonald's and then stapling the chicken nugget box to your leg so all day long you'd be walking around people go oh you had chicken nuggets so this macrophage is now presenting these bacterial antigens so your cd4 T cell is gonna dock with that bacterial antigen we don't want to kill our macrophage this is like killing our trash guy this is a good guy but we want to react to that antigen in case we see it again so this cd4 cell reads that bacterial antigen and says okay we're gonna be on the lookout to kill any of these cells that have like any bacteria to have this antigen so we're gonna copy ourselves we're gonna become helper T cells helper T cells activate and alert all the other branches of your immune system like the inferior interferon if this was a virus or the prostaglandins or the any of those other chemokines that were on that list the tumor necrosis factors if those are necessary like so whatever chemical lysozymes whatever chemical we need in whatever situation this is this guy's these helper T cells are gonna activate it so that's why I have a little picture of Paul Revere even though Paul Revere wasn't the only person that was running through the town saying the British are coming the British are coming he was an early alert system to let us know we were being invaded we also want to copy the cd4 cells into memory t-cells so that way if we see this bacteria again we will know he's bad the problem is this is kind of a design flaw right we are putting all of our immune system hopes and gene and dreams into one basket if there's a problem with your helper t-cells you can't call in the cavalry for help you can't engage the rest of your immune system and so this is kind of a flaw because unfortunately HIV the virus that leads to AIDS has figured out how to take these guys out so it's like shooting Paul Revere or shutting off the fire alarm system in your building you're not gonna get that early alert that there's a problem we can't activate we can't activate the rest of our immune system so this picture a little bit crazy is just showing the same thing where in this case a virus infects this macrophage he puts the viral antigens on his surface the t-cells then bond with that antigen and realized okay this is the enemy so we want to create helper t-cells in case we see this antigen again we'll be ready to activate our entire immune system and memory t-cells in case we see these again but this picture is also showing the B cells and the B cells are what make your antibodies so you can see that your b-cells are responding to that same antigen we're gonna turn out antibodies against that virus so this is pictures showing both t-cells and b-cells same thing with this picture this is showing B cells and T cells so when there's a foreign antigen in our body our B cells make antibodies to clear it out but we also want to create the memory B cells in case we see this again we do the same thing with the T cells we want to activate them so that way they can kill cells that have that antigen and will remember them for next time the cd8 cells are killers so I always remember this because I think if you ate something you killed it I mean not necessarily of course but everything we eat used to be alive so it's just the way that I remember the difference so these guys are killers so these are gonna recognize non immune cells presenting foreign antigens and kill them so again this doesn't make much sense so I tried to draw it out so the difference between this picture and the last one this is now a body cell that has been infected so this isn't your garbage man this isn't one of your very valuable macrophages that's cruising around looking for bad guys this is just simply a plain old cell so this could be a liver cell a skin cell a brain cell a muscle cell a fat cell that's been infected you've got millions of these so if this guy gets infected he's gonna take one for the team in the sense that we want to kill him so I kind of like to think like if I had some kind of horrible disease I would either want to be in isolation to protect everybody or you have my permission to take me out like I wouldn't want to spread like Ebola to like 10,000 people and kill them so it's the same thing here this is a body cell that we can sacrifice because we got tons of them so if the body cell gets infected he puts the antigens of whatever infected him on his surface whether it's a virus bacteria whatever so this would basically be like you have a cold and so you put a little sign on your body that says I have a cold or I have the flu so the cd8 cell is gonna dock with that antigen realize the cells infected and kill it because it's better to kill this cell than to let this infection spread but again what are the odds that just one cell is infected so we want to be prepared so the cd8 t-cells clone themselves into memory cells in case we see this an antigen again we're ready to go cytotoxic T cells these are very aggressive cells that are now going to cruise around your body looking for this particular antigen if they see that antigen they will kill that cell and so that's pretty intense right so we also have the suppressor T cells that will suppress the cytotoxic T cells so I think of cytotoxic T cells like the Navy SEALs that is a whole branch of our military that's kind of intense what we expect the Navy SEALs to do is crazy and so sometimes they'll just get so into killing they'll get so into their mission that they almost forget like okay I need to kind of dial it back a little bit but that's what the suppressor T cells are for they're there to kind of say you know what you're overdoing it don't go too crazy so this is just reviewing the different t-cells don't worry about cell-mediated it just means self-controlled and we don't care so for populations of t-cells the memory t-cells so that way if we see this antigen again we can respond a lot faster helper t-cells are helping out all of the rest of your immune response suppressor T cells keep the cytotoxic T cells from working too hard so it actually decreases that immune response and the cytotoxic or killer T cells are cruising around directly killing cells with chemicals with that per friend that we saw earlier so I just visualize them kind of stabbing other cells to death they actually have to make physical contact to kill I love this picture because it's showing how aggressive that cytotoxic t-cell is taking on that cancer cell so he's basically stabbing it you can see those little cytoplasmic extensions coming off there to stab it to death so it's inserting this chemical into the target cells membrane and poking holes in it what do all of the specific defense mechanisms have in common it's all about the antigen so it's all about fighting a particular antigen if you get a polio vaccine that is going to be looking for the antigens that are on the polio virus it is not helping you against a cold virus it affects the entire body so no matter where that virus or bacteria or whatever enters your response will be the same and it's about making memory cells memory cells are how we become immune we have to remember these antigens so our immune response is quicker the second time so if I get a cold and I pass it to Brent I feel like crap for two weeks I get over the cold Brent gets sick he's coughing and sneezing he gives me the virus back but I now have a weapon so I don't have to go through the two weeks of feeling like crap because I have these memory cells that remember that antigen and I attack it this is something I stole from the internet so it has some good things and bad things like I don't care that you know which ones effective against cancer and which ones affected against viruses it's basically just summing up what we just did that the B cells are there to make the antibodies making those plasma cells which turn out the antibodies to fight the good fight and we have our memory cells to keep us immune whereas the T cells we are not making any antibodies we're making memory cells so we know that this guy is the enemy but we're not making any antibodies these guys do direct killing remember they're stabbing those cells to death