All right in this video I wanna go through the different types of hypersensitivity and then talk about a few examples. So first we have type one which are anaphylactic reactions and then the time beginning it's very very quick some people it's immediately accidentally get exposed to a peanut or something and their reaction is immediately. Here's the key that IgE and I'll show you an image of this IgE binds to to mast cells or basophils and both of that when IgE which is those are the antibodies associated with allergic reactions when they bind to a mast cell or basophil you get a degranulation when it's released is very inflammatory react to something this is primarily histamine. There are other ones but histamine's the big one. So that's why if you're having an allergic reaction there's a couple of things you can do. An antihistamine would be a good idea if it's a minor deal but if it's a more serious one you need something to really to deal with these symptoms like the shock instead of the actual problem. So like an antihistamine would help stop these mast cells or basophils from releasing from releasing histamine whereas if you were actually having an anaphylactic reaction you need epinephrine just because it counteracts the problem. What happens is during an anaphylactic reaction your airway closes up and your blood vessels open which is what happens in a parasympathetic state. So you use epinephrine to jack up your sympathetic nervous system to close the blood vessels and open the airways. All right so let's go ahead and I do have some images here we'll go through. So here we see an example. You see IgE antibodies there once they've been triggered by an antigen. So you see that right here. Once they've been triggered by an antigen they're gonna cover mast cells and basophils and when that happens that's gonna cause the release or degranulation of a mast cell or basophil releasing histamine. So here you see it actually happening. That's like an antihistamine and those kind of drugs and stuff their job is just to stop this degranulation process. So histamine's definitely the most important one. It makes your blood vessels very permeable and stretches them out which is gonna cause the swelling and redness and those kind of thing. You're gonna get a lot of mucus you're gonna get muscle contraction which is gonna make it difficult to breathe. All those kind of things are going to happen. There are other ones too. There are very inflammatory things like I call them like they're hormones but they're cell to cell communication like prostoglens and leukotrienes. Those are gonna play a role as well. So that's why you're gonna get all that inflammation and swelling and muscle contraction of your lungs and all that mucus is gonna occur during this process. All right so that's what would happen during a type one or anaphylactic reaction. So what the big concern would be then would be anaphylaxis. So you have what's called anaphylactic shock. So basically what happens is you know when you think of shock when I think of shock as losing blood. Losing or % of your blood volume but what happens with this what happens with anaphylactic shock is not that you're losing blood but all your blood vessels basically dilate and you don't have enough blood because you get a huge drop in blood pressure. So it definitely can be fatal. It does kill some people. I'd say bee stings and stuff would be the most common example of a fatal one. That's why you want to make sure you have the EpiPens the epinephrine in order to deal with that. So this would actually be what would happen. People that are allergic to penicillin this is actually what would happen. Penicillin can actually partially bind to these and cause some problems. And so if you're allergic to penicillin this would actually be why you would be. You could develop and type one anaphylactic reaction. All right there are some weird things you can do to desensitize yourself from these let's not talk about that. So that's a systemic anaphylactic anaphylactic shock is a life-threatening one but many people get what is called localized anaphylactsis where there might you know if you're exposed to something it might asthma would be an example where it only affects your lungs or maybe it only affects like mucus membranes in your nose that kind of stuff. So those would be some examples of a more localized type of anaphylactics. Hives I guess hives would be a good example as well. All right let's see if you're looking to identify reaction like I put here. Just look at these these are some things that would cause allergic reactions like pollen and dust mites. Here we see an actual test. These are not the best tests in the world. There really aren't a lot of really good there really aren't any good skin tests or any tests for that matter. So really with allergies it's almost like avoidance or like an elimination provocation situation would be your best bet. You know you just avoid the foods that are potentially allergenic or whatever else. You kill your dust mites by washing stuff and that type of thing. All right so that would be those are some good examples of your type one reactions. The type two reactions I've done a separate video on blood typing hemolytic disease in the newborn. But type two or cytotoxic reactions they usually occur in five to hours. So instead of IgEs IgMs and IgGs actually cause complement to be... Complement is one of your defenses that actually can drill holes in the cells basically. So the transfusion reaction in the hemolytic disease of the newborn would be the best examples of that. All right next we have a type three or immune reaction. So you've heard I'm sure you've heard of these in some way shape or form but type three reactions as you see here they're gonna form complexes. So type three reactions they work against soluble antigens that are in the serum of your blood. So instead of it being like a cell structure it's actually in the serum of your blood where this is going to be an issue. It's usually gonna be igGs that's not on here but igGs play a major role in the type three immuno complex reaction. I'm trying to think of the best example to share with you here. While there certainly are some immune reactions that can cause inflammatory kidney diseases that can actually kill the kidneys that are type three. And lastly we have your type four or delayed reactions. Or what are called delayed cell mediated reactions. So let's go ahead and look at an example there. I think I have one. Let's see what it says here first. So these can be delayed reactions to hours. The trick with this stuff is that it's hard to know especially like with food or exposure of something it's hard to know like that's why if you're doing elimination provocation diet you want to only add foods back in very very slowly. Let's say if you eliminate all these potentially allergenic foods and add milk back in a day and then in two days add something. Well it could be and then you have a problem that night it could be a quick reaction to whatever you ate today or a more delayed reaction to whatever you ate two or three days ago so keep that in mind. So type three's not that important type four though this is going to be if your body the graft host of these if your body rejects transplanted tissues poison ivy and those kind of things are gonna be a type four reaction. These are gonna take a little longer. I'm trying to think... Latex allergies would be a delayed reaction like this contact dermatitis would be an example of this the skin test tuberculin skin test you guys had to do test for TB would have been an example of this one as well. So all right these are gonna be your examples of delayed reactions. I'm just gonna go ahead and show you an image here. Let's see I've covered that one that one that one. Well this is actually this is gonna be how you can create something called thrombocytopenia proferand but that one's not a big deal. Let's go ahead and I'm trying to think if we should cover this one. This is an immune complex one this is what happens at type three. Just remember that it happens notice that it's not happening on cell surfaces it's happening in the serum there so nothing to know there. And then here we have your contact dermatitis. So you see that the chemical from the poison ivy can combine with your skin proteins and form this reaction. So you can get the actual contact dermatitis there. So really nothing to know there. I just wanted to go through them all just this is not a very important video to be completely honest. I probably should have told you that at the beginning eh? But this is just over some different examples of types of hypersensitivity.