Immune System | Summary

welcome to this video on the immune system this is a review of the immune system and it could be intended for a student that is preparing for an exam on the immune system such or standardized exam like the tea's test or just a basic overview maybe when you're first starting to learn about the immune system so the immune system is divided into two parts there's the innate immune response and there's the adaptive immune response and we will discuss each of these separately and then talk a little bit about how they are related if the innate immune response had a nickname nickname it would be I was born ready baby now even though babies might not have a strong of an innate immune system as an adult they are born with the ability to do all of these innate responses and compare that with the adaptive immune response which if it had a nickname it would be I'm always up to learn I'm always ready to learn and remember because memory cells are going to be a big part of its response and then if we were going to give just a couple of important points the idea is is that in the innate immune system these cells and mechanisms are immediately able to act upon pathogens are able to immediately act on pathogens they don't need to be activated they do not require activation and let's go ahead and put a box around that in orange because that's a key idea to compare it with the adaptive immune response the adaptive immune response of dead require activation so these cells the T and B cells that we'll talk about require activation and then a second thing is that they react and respond to a specific pathogen not to just anything that is different or strange the way the innate response would and then the third thing is that once they do respond and take out the pathogen they form memory cells and these will protect you from getting sick with that pathogen hopefully ever again okay let's go ahead and put a box around that in orange now we're going to go back to the innate immune system and talk more in depth about that so the innate immune response has physical barriers chemical barriers chemicals called complement that punch holes and cell walls and inflammation so for physical barriers these are things like your skin and your mucous membranes these are the parts of your body that first come into contact with the potential pathogens we can go ahead and highlight physical barriers in yellow chemical barriers are things like saliva that contained before all of your bodily secretions that contain an enzyme called lysozyme and that is capable of breaking the bacterial cell walls sweat has chemicals in it that are able to help neutralize pathogens things like stomach acid would also fall under this category of chemical barriers so you can go ahead and highlight chemical barriers in yellow next is compliment a compliment is a bunch of chemicals that are always circulating in your blood and when they are encounter a pathogen or somehow are triggered by some other part another white blood so let's say that turns them on so I guess in that sense it's a tiny bit of they do require a little bit of activation here but these chemicals will bind together I'll put triggered instead of activated when triggered I'm going to turn this a little bit to sorry a minute like this okay that when triggered form a complex that's called a membrane attack complex and they punch holes in the cell membranes of pathogens and so they can punch holes and then inflammation most everyone's heard of this it has some Cardinal symptoms those Cardinal symptoms are that the area that is inflamed is red because of increased blood flow it's hot because of increased blood flow it's swollen because of increased blood flow and it's painful because the pain receptors in the area are both stretched and become more sensitized during inflammation so these are the Cardinal symptoms of inflammation notice that all of them have to do with the blood vessels becoming more leaky so that an area can have more blood flow which can contribute to fighting the overall infection so the leukocytes that are involved in the innate immune system are most of them let's go ahead and put that in orange and we're going to compare the leukocytes involved in the innate immune response with the adaptive immune response when we get to that part - so these are some different white blood cells that are involved first of all neutrophils these are granulocytes that are able to secrete chemicals they're very common the most common kind circulating in your blood and then there are basophils and these are named because they are basic loving and they have granules that will take up purple colors when we stain them and so if you see them under a microscope they usually just look really purple and these secrete histamine so I'm gonna put under neutrophils if they're very common and they can release bleach and peroxide and we compare that with basophils they release histamine and they're very closely related to a cell called a basophils that's found in the mucous membranes I'm actually going to put there sorry did I say they're very really closely related to a cell called a mast cell that is found in a lot of mucous membranes in the tissue so basophils are more circulating in the blood mast cells more in the tissues and then a third kind of granula site meaning has all these granules in it these ones are acid-loving and they take up an acidic pink dye and so we call them escena fills that means acid-loving in greek and these seem to be very important in fighting off like parasitic helmets so worm infections parasitic worms and they also seem to be quite elevated in allergies then another kind of white blood cell for leukocyte that is involved in the innate immune response is a cell called a macrophage so macrophages just like they sound they're big eater they're very good at phagocytosis and then there's this kind of cell that's very similar called a dendritic cell and both of these together are what we call antigen presenting cells and they are going to present antigens to a different kind of white blood cell to start off the adaptive immune respond this response these are antigen presenting cells and those include macrophages and dendritic cells are antigen presenting cells okay and then we'll go ahead just a little bit lower down here and then this last kind of cell that I've drawn here is meant to represent a natural killer cell now this cell is a lymphocyte and we sometimes think of lymphocytes as being more associated with the adaptive immune response but natural killer cells get to stay in the innate immune response category because they do not require activation now a note to remember is that all leukocytes no matter what kind they are originate from the bone marrow they're all produced in the bone marrow and then they differentiate that means they become different from each other and the lymphocytes of the adaptive immune response they have to go to the lymph organs generally for their final maturation and what I like to call training to be good lymphocytes and that's a process called hematopoiesis that makes all of these let's go ahead and box this in green alright and now we'll talk about the adaptive immune response so I already told you that these hats cells have to be activated well how do they get activated it starts with what's called a helper T lymphocyte and these helper T cells are activated by antigen-presenting cells and those are the cells that we mentioned the macrophages and the dendritic cells so once a helper T cell is activated by an antigen-presenting cell it will stimulate other kinds of white blood cells these are called cytotoxic T cells and so sorry another room to put this here cytotoxic T cells and then B cells let's go ahead and highlight our lymphocytes in purple so helper T cells when they get stimulated and are activated by an antigen presenting cell then they stimulate cytotoxic T cells and B cells now the cytotoxic T cells they are able to directly attack pathogens so if you can pretend that this is a pathogen is directly destroyed by the cytotoxic T cells and then B cells when they are activated they get really really big which I didn't draw that too much on here but imagine that it gets really really big because it's gonna become an antibody making machine so all its gonna do is make antibodies and so when we see these under the microscope instead of calling them B cells at that point we call them plasma cells because they're filled with so much cytoplasm as they are making the all these proteins and so will make the antibodies in orange here so these plasma cells produce antibodies and then the antibody stick to the pathogen and they start to take it out of commission and both by stopping it from doing what it wants to do and also the presence of the antibodies make cells like macrophages really attracted to it and then they're more likely to engulf that pathogen okay you might notice that I have some little cells right here and these represent memory cells and so after the B cell has been activated it will multiply itself and some of these will become memory B cells and when the T cell is activated it will then multiply and some of the cells will become memory T cells and then those are the ones that will circulate potentially for the rest of your life occasionally I'm going through mitosis to keep the population fresh and that will protect you from future onslaught of whatever it was that made you sick the first time and then maybe you'll never get sick from that again if adaptive immunity works properly so then just a little more about those leukocytes so the two that are involved they're both lymphocytes this is a T lymphocyte and I just talked to you about the helper and the cytotoxic T cells and there's also suppressor T cells it appears that there are many different kinds of T cells that sort of fine-tune and regulate this response and then B lymphocytes are the other kind of cell involved and these are patrolling through your body and I want to end with just a little explanation of how they do that patrolling so if you look at this bottom picture this represents a blood vessel and you're gonna have white blood cells that are circulating you know in this blood stream so these represent blood cells or white blood cells and they are able to Patrol and they enter the tissues if needed and then they drain from the tissues via the lymphatic vessels and so they're these lymphatic vessels don't have red blood cells in them so they just contain water and other things that have drained out of the cell I'm gonna put this in yellow this tissue so and so these white blood cells are also traveling in your lymph the lymph is the name for the fluid that is in there and then they pass their limp organs like your tonsils your appendix maybe I'll put a remind you on here the tonsils the appendix the thymus these are all examples of lymph organs and then all of your lymph nodes too so these white blood cells pass through these lymph organs and most of them are actually hanging out there and they are always on patrol so that in just a few minutes is a summary of the immune system good luck with whatever you're trying to learn today see you in the next video

Channel: susannaheinze

Views: 129,778

Rating: 4.9260654 out of 5

Keywords: immune system, lymphatic vessels, T cells, B cells, antibodies, innate immune response, adaptive immune response, granulocytes, natural killer cells, neutrophils, eosinophils, basophils, mucous membranes, complement, lysozyme

Id: QdYuibhnUuE

Length: 16min 10sec (970 seconds)

Published: Sun Apr 28 2019