 Good morning, everyone. Am I audible to you? I am audible to you all, okay. The screen is visible, no? The screen is visible or not? We will be discussing immunity first. Immunity first. What do you people understand by immunity? The word immunity. What is the meaning of that? Just a minute. What is the meaning of word immunity? Tell me that immunity is the ability of your body to defend itself against infection. Yes or no? It is the ability of... Just give me a minute. I am trying to... Just a minute. Yes. Am I audible now? Some technical issues are there that I was trying to fix. Now it's okay. Yes. Let's see. Let's see. We have to discuss immunity. Okay. Immunity. What is immunity? Immunity is the ability of body to fight against the disease or you can say infection. This is there. This is the definition. These days, you people keep on hearing. Immunity booster should be there. Okay. That is going to help you to build, you can say, fight against corona and all. Now sound is okay. Himanshu. Himanshu sound is okay now. Okay. Let's see. If you will talk about immunity, basically, immunity is of two types. One is innate immunity. One is acquired immunity. Yes or no? One is innate and another is acquired. Meaning of innate immunity is it is present from birth. Okay. A child who has born. Okay. Even that child have this kind of immunity. This is known as innate immunity. Okay. And acquired is what? That person or that organism that is going to acquire it during the lifetime. Yes or no? You people can reply a bit. You people can reply a bit. Agreed? You people can, you can say over here it is present from the birth and it is present. You can say quite during lifetime. One important thing is, one important thing is innate immunity. It is known as specific and it is specific or adaptive. Why it is so? Can you people tell me? Anybody? What is the meaning of being a specific or non-specific? What is the meaning of that? What is the meaning of a specific or non-specific? Try to understand. You have always some kind of ability to fight against any organism. Whether it is tuberculosis bacteria, whether it is some virus, etc. Okay. This will act against everything. Yes or no? This will act against everything. But what about acquired immunity? Do everybody have immunity against COVID-19 right now? Do everybody have immunity against COVID-19 right now? At this point of time? No, it is not there. Because once COVID-19 virus is going to infect the body, then only we can develop immunity against COVID-19. Okay. And that kind of immunity which will be acquired because of infection from COVID-19 virus will be only for COVID-19 virus. Yes or no? It is not going to work against the tuberculosis bacteria. It is not going to work against the tuberculosis bacteria. Agreed? So if you will see innate immunity having four barriers. One is the physical barrier. One is physiological barrier. One is cellular barrier and one is cytokine barrier. What all components are there? That is going to produce you people immunity right from the birth. It is physical barrier. It is physiological barrier. It is cellular barrier. And it is cytokine barrier. Later on we will see that. Let's see. What is the meaning of physical barrier? What is the meaning of physical barrier? If some of the bacteria settle down on your body, this is bacteria process, settle down on your body. Agreed? Now this bacteria has to cross your skin. If some bacteria is going inside your oral cavity, it has to cover the mucous membrane present in the ural cavity. So any bacteria or virus or any pathogen, pathogen is disease causing agent, is pathogen. Any of that is there. In that case what will happen? Tell me what will happen? Understood? In that case that bacteria or virus or any fungi, anything that is there has to cross your skin, mucous membrane, etc. So a skin forms, you can say physical part of your innate immunity. What if some of the, like you are eating food and some bacteria is there in the food? What will happen? Try to understand my point. You are going to chew the food. In that case what will be there? Lysozyme is present in the saliva. Lysozyme is present in the saliva. So do you know what the Lysozyme is going to do? It will dissolve, dissolve, it will dissolve the peptidoglypen, peptidoglycan. What is peptidoglycan? Please let me know dear. It is present in cell wall of bacteria. It is present in cell wall of bacteria. Yes or no? Peptidoglycan is present in the cell wall of bacteria. Agreed? Everyone? Lysozyme present in saliva is going to dissolve the peptidoglycan. In that case the bacteria will be killed. So if somebody will ask you, which is the antibacterial agent present in saliva? What will you say? What will you say? Tell me. Lysozyme. Yes, great. The thing is everyone is getting a yes. Some of you are replying, some are not. So if you know that in a stomach also HCl is secreted. Even it is going to act as antibacterial agent. Not only antibacterial, you can say antipathogen agent. Many other pathogen will be, are going to be killed by this acid that is secreted from stomach. So in this case, if some pathogen is crossing your physical barrier in that case or going to enter inside, these are there to assist the physical barrier. Yes or no? Physiological barrier. Understood? Physiological barrier is there to assist the physical barrier. Till now the pathogen has not entered your body. Hence they are known as external barrier also. Agreed? Till the bacteria is there in the lumen of stomach or in oral cavity or on the skin. It has not entered your body. Hence they are known as external barrier. Now what if bacteria or any other pathogen that is going to cause disease enters your body? What will happen then? Tell me. What will happen then? If bacteria be able to cross your physical barrier and you can say physiological barrier, after that how things are going to be managed? There are certain cells in your body that is going to attack that microorganism and going to kill it. Yes or no? Tell me. There are certain cells in your body that will attack that microorganism and going to kill it. Tell me dear. Do you people agree with me? Do you people agree with me? Yes. Next thing. If the bacteria or any pathogen is going to clear your physical and physiological barrier, in that case now comes cellular barriers in play. Let's see. One is polymorpho-nuclear leukocyte. Polymorpho-nuclear leukocyte. Polymorpho-nuclear. Why it is polymorpho-nuclear? Because this cell having nucleus which is multi-lobed. You people can see. Isn't it? So multi-lobed nucleus is there. Its nucleus keep on changing the shape. Hence the word polymorpho-nuclear leukocyte is used and this word is used for a cell present in the blood known as neutrophil. Neutrophil. It is having multi-lobed nucleus. And what it do? It engulf the microorganism. What is that process known as phagocytosis? It is present in the case of acute infection. Okay. If you will doctor, if doctor will see your blood report. Yes. That is neutrophil only. Okay. I have written over here. They are neutrophils. Okay. If doctor is going to see your blood report. He is going to understand. He is going to understand whether it is acute infection or chronic infection. How it is possible? In acute infection, he will see neutrophil in more number. Acute means a fresh infection that has taken place within 72 hours or so. Okay. Then comes monocyte. Monocyte is there for chronic infection. A long-standing infection. Yes or no? A long-standing infection that is there. Like something which is older than 72 hours or so. Or you can say one week like that. If doctor will see increase in monocyte in your blood, he will understand that infection is older. And if he will see, neutrophil is there in the blood, he will understand that the infection is acute. Means that has taken place some time back only. Then comes macrophages. What do you people know about macrophages? Please tell me dear. What is your concept of macrophages? Have you heard about this cell? Have you heard about this cell? What is the relation between monocyte and macrophages? Yes, what is the relation between monocyte and macrophages? Anybody else? Monocytes are macrophages. Yes, somewhat you are right. See, monocyte is there in the blood circulation. Monocyte is there in the blood circulation. Till it is there, in the blood circulation, it is monocyte. Once it comes out in the tissue space, it becomes macrophages. Okay. So, the monocyte is going to become macrophages. Once it enters the tissue space. Yes or no? There are two types of macrophages that you people need to know. One is fixed macrophages and one is wandering macrophages. Okay. Fixed macrophages are going to remain inside some particular tissue. Some particular tissue and wandering macrophages are there. They are motile and keep on moving through the tissues. Some examples are there. Like dust cell is there. It will remain in the lung only. If somebody will ask you, macrophages of lung is known as. What will you say? Okay. Let's see. One question is there. The process of phagocytosis is performed in lung by. First is dust cell. Second is osteocytes. Third is cuffer cells. Fourth is osteoclast. What do you think? What will be your answer? What will be your answer? Please tell me, dear. It is dust cell in the lung. It is osteocytes in connective tissue. It is cuffer cell in liver. And it is osteoclast in bone. And it is microglial cells in brain. Everyone agrees? Do you have any doubt in this? What is the meaning of fixed macrophages? Fixed macrophages are going to remain inside a particular tissue. One more cell that is required over here is natural killer cells known as NK cells. What do you think? What is the role of natural killer cells in this? What is the role of natural killer cells in this? How natural killer cells are going to create, you can say, kill a pathosin? How it is going to kill? Let's see. It is going to create a pore over here. It will create a pore. All the cytoplasm will move out and this bacterial cell will be killed. So how natural killer is going to kill? It is going to kill by creating pore in the cell. Yes or no? It takes part in apoptosis. Do you know what is the meaning of apoptosis? This word apoptosis, see apoptosis is programmed cell death. All your cells, after you can say completing its life cycle has to be killed in a programmed manner. The cell also ages. After aging what happens? That cell has to be killed. That is known as apoptosis. Apoptosis is programmed cell death. All your cells present in the body are destined to be killed once it completes its life cycle. Yes or no? So this is the cellular barrier that is there. Either a skin will not let the bacteria go in or the physiological barrier like, you can say, a seed in the stomach or lysosamine saliva is going to kill the bacteria. If bacteria will enter into the cell, if bacteria will enter into the, you can say, body rather, if it will enter the body then cells present over there is going to kill it. Now, do you people know what is the process of egocytosis? What is the process of egocytosis? Aditya is asking sir, how does that happen? What? Creating pores? Aditya? Apoptosis, see apoptosis is actually genetically programmed. Okay, cells are there. Natural killer cell will come. It will create pore in the cell. Okay, and say after creating pores, what will happen? Similar thing will happen. The cytoplasm will move out and cell will be dead. Yes or no? Cell will be dead. Yes or no? Yes. Now, do you know what is egocytosis? Do you people know what is egocytosis? Egocytosis is the process of cell eating. How? Cell is going to eat something that is not beneficial for your body. Let's see. Try to understand my point. I have some pathogen over here. Can you see this pathogen? I have some pathogen over here. That pathogen is going to attach to the cell membrane of egocytic cell. Yes or no? You see this point. It will be attached to the cell membrane of the egocytic cell. Agreed? Agreed? Now you see. It will form an inward depression like this. It will form an inward depression like this. After that, you say, see, this point is going to be closed over here and will break up from here and there is a vacuole that is formed known as phagocytic vacuole. Pathogen came, attached to the cell membrane, invagination is formed and after that this invagination will break off and will form a phagocytic vacuole. Yes or no? Everyone? Any pathogen has arrived, got attached to the cell membrane of the phagocytic cell. Invagination is formed and that invagination breaks off to form a phagocytic vacuole. Step one, two, three, step four. Have you people understood? Tell me. Got it? Yes or no? Yes. Now you see. Do you people know Lysosome? Lysosome? You are aware about Lysosome, no? Yes. What is the content of Lysosome? What is the content of Lysosome? Please let me know. What is the content of Lysosome? Enzymes. Which kind of enzyme, dear? You told enzyme. Which kind of enzyme? Hydrolytic enzyme. Yes. Hydrolytic enzyme. Okay. Lysosome content is a hydrolytic enzyme. It will digest everything that is present in this bacteria or the pathogen that is there. Once phagocytic vacuole is formed, it will fuse with primary Lysosome. Primary Lysosome. If somebody will ask you, what is primary Lysosome and what is its content? Primary Lysosome only contain the hydrolytic enzyme. Now you see, once it will fuse with it, this bacteria is inside the hydrolytic enzymes. So what will this enzyme do? This enzyme will digest the bacteria, fungi, etc. Whatever is there, it is going to digest that. Any pathogen you can see. You can say, hydrolytic enzyme present in this Lysosome is going to digest this entity. It will digest it. After that, what will happen? It will be released from here. You can say few useful things are there. Useful things are there. Useful things are there. That will be released. And those things that are not useful will be kept inside this. This is known as residual body. So what is the content of residual body? The residual body contains waste substance after, you can say, left after digestion is over. Now you see, this residual body will go, will fuse with the cell membrane and all the content is, you can say, forced outside by the process known as exocytosis. One is phagocytosis and one is exocytosis. So what will happen? Try to understand my point. A pathogen came, attached to the cell membrane, form an invagination. After that, a phagocytic vacuole is formed. Once it will attach to the Lysosome, it will form phagolizosome. Now after digestion is over, useful substance are taken out. Wastes are excreted through residual body as the process known as exocytosis. So phagocytosis is the process of cell eating. Yes or no? Tell me, are you people clear with phagocytosis? Yes. Now we are saying, yes. Anybody having doubt? You people actually understood the role of Lysosome in your body, in your cell actually? It is the cell organelle. So it is rightly to say, it is present in the cell. So in this way, okay, now one is cytokine barrier. One is cytokine barrier. What is that? Cytokine barrier is through. Tell me cytokine barrier. What are cytokines? What are cytokines? Please let me know. Cytokines are cellular messengers. Cytokines are cellular messengers. What all cytokines are there? They are interleukins, lymphokines and interferos. They are interleukins, lymphokines and interferos. Agreed? What are cytokines? The word cytokines means cell. They are cellular messengers. They actually communicate between the cells. What is the role of interleukins? Interleukins. It communicates between leukocytes, lymphokines. It is for lymphocytes. Means they communicate between the lymphocytes. Then interferos. What is interferos? They are going to protect against the viral infection. One cell is going to release these interferos to protect other cells. If viral infection will be there, in that case it is going to protect against the viral infection. You people keep on hearing this thing that viral infections are self-limiting. Viral infections are self-limiting. What is the meaning of that? Self-limiting. You people have common cold. You keep on acquiring that disease, that sneezing and mild fever. So that is common cold. Agreed? Common cold is there. You people have not heard about common cold. This is a viral disease. It gets cured in 3 to 7 days itself. You do not require any medicine from outside. Antibiotics, you people are going to take in case of bacterial disease. Agreed? So, see over here. Due to these interferos, the bacterial disease, viral disease are actually viral disease. Due to these interferos, viral diseases are actually self-limiting. What? Self-limiting. They will usually get cured itself. You do not require any other intervention. Whether it is dengue, whether it is common cold, it will be cured. You can say on its own. Now, I will be talking about acquired immunity. Acquired immunity. What is the meaning of that? It is acquired during lifetime. It is also known as adaptive immune response. Because it is a specific. Because of that only, it is a specific. A specific means it acts against some particular disease. Agreed? It acts against some particular disease. Yes or no? Tell me dear. It do not act against, because it is not like, if you try to understand my point, I am going to write again. If it develops against some disease, it is effective against that disease only. Yes or no? Tell me. Tell me. Yes. Now, try to understand my point. Acquired immunity is of two types. One is immoral and one is self-mediated. One is immoral, one is self-mediated. Immoral is due to B lymphocytes and self-mediated is due to T lymphocytes. Agreed? Now, try to understand my point. What happens? This is your bone marrow. What do you think? What is the difference between B and T lymphocyte? Tell me that B lymphocyte as well as T lymphocyte. B lymphocytes and T lymphocytes. Both are produced in bone marrow. Yes or no? Where are they produced? Where the production had happened? It is there in the bone marrow, but maturation of T lymphocyte takes place in thymus. Hence, the word T lymphocyte is used and its maturation also takes place in bone marrow. Hence, this B. Agreed? Agreed? Everyone? No issue? Try to understand my point. What I want to tell you all? See over here. Some bacteria, virus or tumor cell is there. It will circulate in your blood. It will be caught by antigen-presenting cells. You know what antigen-presenting cells are there? Like in your school, PT teachers are there. If you people are caught doing some unruly things, that PT teacher is going to catch you and will present you against the headmaster or the principal. Yes or no? If you get caught doing something that is unruly, you can say you are going to be caught by your PT teacher and he will take you to the headmaster. Yes or no? Or the principal? Yes. The same role is done by antigen-presenting cells. What they do? They are going to catch any bacteria, virus or tumor that is circulating in your blood. And it will take that cell to, you can say T lymphocytes. It will take that cell to T lymphocyte or B lymphocyte. Yes or no? So they will ask you what all antigen-presenting cells are there in your body? You will say dendritic cells, macrophages and lymphocyte. There are three. This is important one. Agreed? See over here. So if you will talk about humoral immunity, what is the meaning of that? Humoral immunity? What is the meaning of word humor? Tell me. Humor means your body fluid. Humor means your body fluid. Yes or no? What happens? The antibody secreted by B lymphocytes, secreted by B lymphocyte. Try to understand my point. Antibody secreted by B lymphocyte are dissolved in the body fluid. Hence they are known as humoral immunity. Agreed? You people understood this thing? Now you see. What is antigen and what is antibody? What is antigen and what is antibody? See there are certain substance present on the cell surface. They are certain substance present on the cell surface are known as antigen or immunogen or aglutinogen. Try to understand my point. That is the identification of this cell. Identification of this cell. Yes or no? If some cell, try to understand my point. What I want to tell you all? If some cells that are there, getting my point, it is circulating in our blood. Yes or no? How our body is going to recognize whether this is, you can say our own cell or they are the foreign cell? How the body is going to recognize? By this antigen only. And with response to this, you can say your B lymphocytes are going to secrete a substance that is known as antibodies. Yes or no? What are they? What are they? They are gamma globulins. Do you know how many types of proteins are there in your blood? Do you people know how many types of major proteins are there in the blood? Tell me dear. How many types of major proteins are there in the blood? Anybody? It is fibrinogen. No. Major proteins I am asking. It is fibrinogen. Okay. It is albumin and it is globulin. Globulins. Okay. So what is the function of globulin? Question is what is the function of globulin? One is immune defense. Second is blood clotting. Third is coloid, osmotic pressure. Fourth is bleeding. What do you think? What is the function of globulin? They are forming your antibody. Antibodies are gamma globulin. Gamma type of globulin protein. So the answer will be what is the function of globulin? Tell me dear. Can you tell me? No. I have told you now only globulins. It will be immune defense. Blood clotting is the function of fibrinogen. Colloid, osmotic pressure is the function of albumin. Go and read your blood part. Answer will be immune defense. So if you will talk about immural immunity, it is brought about by building pocytes. They are going to secrete gamma globulins and they are antibodies only. They are only known as antibodies. Yes or no? Now, important thing. What is the structure of your antibody? What is the structure of your antibody? That is being produced in your blood. If you will talk about the structure of antibody, this is there. See. You can see one is the light chain and one is a larger heavy chain. Yes or no? So how many light chains and how many heavy chains you people are going to see in this antibody? How many of them are there? How many light chains and how many heavy chains are there? APC, antigen presenting cell. Yes, I will go. Let's see. You want to ask something about antigen presenting cells? Aditya, am I audible? What they do? See, if some bacteria, virus or tumor cell is there, who is going to catch that? To say, who is going to catch that somebody who is a foreign cell has arrived in your body, this antigen presenting cell? It will catch it and will take it to T lymphocytes or B lymphocytes. Any of that? Okay. That is known as T helper cell. Later on, I will let you know. Later on, I will let you know. Now see. You people understood? How many heavy chains and light chains you people can see over here in the structure of antibody? How many of them are there? Tell me. There are two heavy chains and two light chains that are there. Yes or no? You see, how they are connected? There are two Sulfurna. So, what is this known as? Dysulfide linkage. Yes or no? This is known as Dysulfide linkage. Agreed? I am going to tell you. This is Dysulfide linkage. So, how light chain and heavy chain as well as heavy chain amongst themselves? You see, Dysulfide linkage is present between the light chain and heavy chain as well as between the two heavy chains also. Tell me. So, how they are connected? If somebody will ask you which linkage is present in the antibody? What will you say? The Dysulfide linkage, no? Agreed? Now you see. This is the antibody circulating in your blood. Okay. And this is an antigen present on the surface of some bacteria, etc. Okay. Any of the cell? Do you know? Can you see this site and this site? Can you observe them? Can you people observe them? Tell me dear. What is the difference between them? Either you people reply, yes or no? They are perfectly fitting. Yes. Anybody else? What is the difference between this site and this site? Tell me. What is the difference between them? Try to understand my point. Now definition is there. This site that is present inside antibody is known as antigen binding site. This is known as paratope. What is there? Paratope. So, paratope is an antigen binding site present on the antibody. And what is epitope? What is epitope? It is a site that is present on antigen which is going to fit into the paratope. Agreed? Everyone? Have you people understood definition of paratope and epitope? Tell me dear. What is the difference? Paratope is present inside antibody and epitope is present inside antigen. Yes or no? Do people completely agree by the definition of paratope and epitope? It is important. Agreed? Now you see your light chain as well as heavy chain having two regions. One is variable, one is constant. This is the variable region of light chain and this is the constant region of light chain. Yes or no? This is the variable region of heavy chain and this is the constant region of heavy chain. Yes or no? Agreed? Tell me. Everyone? So if somebody will tell you or ask you over here, try to understand my point. Everyone? If somebody will ask you over here that paratope is present between, I am going to write the lines. You people should be agree with that. I will say paratope is present between the variable region, heavy chain, light chain. Do you people agree? Now you people see this question. If you people agree with answer, it's alright otherwise I will explain. Basically you people try to understand the definition of a structure of antibody first, two heavy chain, two light chain. Then heavy chain as well as light chain having constant and variable region. Heavy chain as well as light chain having constant as well as variable region. Then one is paratope and one is epitope. Yes or no? Yes or no? Tell me. Agreed? Now do you people know what is the linkage between a linkage that is present inside antibody? That is disulfide linkage. You people can see what all places are there. I have shown that over here also. Okay? Same diagram, a cartoon diagram is there. Now you see this question. Which of the following element is required to maintain the shape of antibody? Is it sulfur or not? Is it sulfur or not? Yes. Good. Now I will be talking about types of antibody. I will be talking about types of antibody. Try to understand my point. It is game. G-A-M-E. They are the main types and one more is D. I-G stands for immunoglobulins. Globulin is the name of protein and immuno is there for, because it is there for immune response. Now try to understand my point. What I want to tell you all? One is IgG. One is IgA. You can remember it by G-A-M-E game. What about IgG? Try to understand my point. I will tell you. This is the most abundant antibody that is there. 80% of total antibody that is there. Agreed? One more thing. You people know what is placenta? What is placenta? This kind of antibody can cross the placenta. Only IgG type. You people leave this thing, activate complement system, increase pachocytosis, because I have not taught you people the complement system. Now try to understand. Solve this question. Which of the following antibody can cross the placenta? Tell me. First is IgG. IgA. IgM. Fourth. IgE. What will be the answer? One. Great. See over here. This will be the answer. Now how many paratopes are there in IgG type antibody? How many paratopes are there in IgG type antibody? Tell me that. Two. Great. Ritu is saying two. Yes. One and two. Now in IgA type of antibody, there are two molecules joined together with the help of a J-chain. So that is from a dimer. Can you people calculate how many paratopes are there in IgA type of antibody? How many paratopes are there in IgA type of antibody? Everybody is saying four. So its answer is four. See, now they will ask you which antibodies present in saliva or colostrum. Colostrum is initial. It is present in, you can say milk produced by mother during initial days of, you can say after parturition. So you see over here. If somebody will ask you which type of antibodies present in colostrum. It will be which type of antibodies present in colostrum. It is IgA. In colostrum, in saliva everywhere. See, IgM. What about IgM? Tell me. What about IgM? It is a pentamer. There are five molecules. One, two, three, four, five molecules are joined. So how many paratopes are there in IgM type of antibody? How many antibody, you can say paratopes are there in IgM type of antibody? Can you people calculate? They are 10. Yes or no? Yes. 10. And this is the first antibody that is going to appear after any infection. It appears after any infection. Out of IgA, IgM, IgE and IgD, which is going to appear after, you can say appear first after infection, IgM type. What about IgE? It is responsible for allergic reaction. If somebody will ask you a question, antibody responsible for allergic reactions, what will you say? IgA, IgM, IgG, IgE. What will be the answer? IgE. Agreed? Everyone? Sir, what is the difference between IgE and IgG? See, no. They have different structures. You people see this line. A good question was there. Chemical structure of constant region determines the particular class of that immunoglobulin belongs to. Means, variable region can be same or two antibodies, but constant regions are different. Whether it is the IgG type or IgE type, it is determined by which region of the antibody. Tell me dear, whether it is IgG type or IgE type will be determined by which region of the antibody it is by constant region. Yes or no? So, the major difference between IgG and IgE type antibody in the constant region is there. Yes or no? You got it? The constant region is going to differentiate. So, this is done. If you will talk about functions of antibody, I will like to tell you people this thing especially, opsonization. What is opsonization? By opsonization, the antibody is going to cover the complete antigen. See, involves coating of microorganism by antibody and making it suitable for phagocytosis. Like many microorganisms are there. They are not suitable for phagocytosis and how they became become suitable for it by the process of opsonization. Yes or no? Tell me dear, rest you people can understand. Opsonization is an important thing. Now, do you people know what is primary response and secondary response in equidimunity? What is primary response and see, IgD do not have much defined functions. You see over here, I have written functions are uncertain. Okay, that is produced. You can say that is minor antibody that is there. Okay, its function is not defined that much like others do. Yes or no? So, what is difference between primary response and secondary response and which is more intense? Try to understand. It is written in Hindi. I think you people are going to. Primary response is when first time infection and it is after first time you can say. You can say second time onwards. Onwards. What do you think? What do you think? The first time infection and what is the difference between first time infection and second time infection? Like some disease like a smallpox had happened to me first time. Or chickenpox had happened to me. You can say first time. And if it will be happening again, again, in that case, you see everybody. Have you people understood? Okay. What is primary and secondary response? If any infection is going to happen with you people first time, it is primary response and secondary response. This is the response of your antibody. You can say immune system. This is showing the antibody level. See over here. Here and here, you people can observe. Production of IgG antibody is really very high in secondary immune response. Secondary immune response is very intense. Yes or no? Secondary immune response is very intense. Agreed? What happens? So that is causing secondary immune response to be that intense. See over here. One is B cells. When some antigen or some bacteria is arriving in your body. If some antigen, try to understand my point. I am drawing a diagram. This bacteria is entering your blood. It has entered. Your B lymphocyte is going to change into plasma cells. And these plasma cells are going to produce some antibodies. The B lymphocytes are going to change into plasma cells and these plasma cells will produce antibodies. Yes or no? Tell me. So if somebody will ask you, the antibody is produced by plasma cells or B lymphocytes. And what is plasma cells? If they will ask, what will you answer? Plasma cells are formed from B lymphocytes only. Another name of the plasma cell is cartwheel cell. Cartwheel cells. Because if you will look into the microscope, its nucleus looks like this. Agreed? Everyone? What is cartwheel cells? They are plasma cells. They are plasma cells. Yes or no? Now I am trying to find out reason behind this. Why secondary response? If some infection is happening second time, why it is so intense? Try to understand. Every time infection is there, it is going to produce some memory cells. Which cells? Memory cells. Yes or no? It is going to produce memory cells. Memory cells are there. So try to understand. If the infection is happening first time, your immune system is going to have memory of this. Agreed? Memory of this. And when it will happen second time, these memory cells that was produced during first infection, you can say infection, it will start forming the, you can say, antibody very fast. First time the infection had happened, it has, you can say it has taken some time to produce antibody. But once it is taking place, you can say once it has taken place, after that for second time, these memory cells starts producing antibody very rapidly. So before this bacteria go inside the body and multiplied, you can say it will be neutralized by the antibody produced. You people got the answer? Why primary secondary response is more intense? And which kind of antibody is produced in more amount during the secondary response? Tell me. It is because of memory of your immune system. Yes or no? It is because of memory of your immune system. Yes or no? Tell me. Got it? This is the principle of vaccination also. This is the principle of vaccination also. Vaccination is based on memory of your immune system. Agreed? This is the, this very is the principle of vaccination that is there. What we do in vaccination? It is your blood. See, this is bacteria, bacteria, bacteria having two parts. One is disease causing parts, causing part that is known as Birolenz factor. What? And one part, rest of the part is, the rest of the part do not cause disease. And this is the antigen. Okay? What I will do? I will remove this. Okay? I will remove this. If I am removing the disease causing part, will that bacteria cause disease in our body? Will that bacteria cause disease in our body? Tell me. No. But, try to understand. This antigen is there. This antigen is there. And antibody is produced in your body in response to antigen? Yes or no? Do you people agree? Do you people agree or not? Yes. So, if I am going to put this bacteria inside your body, which do not have the disease causing factor, will it cause disease? Will it cause disease? No. But, will it produce antibodies and memory cells? Everyone. I am saying if I will remove the disease causing factor of the bacteria, in that case, will the bacteria cause disease? Will it cause disease? Yes or no? Only two, three people are replying. You have to reply. Everyone? No. But, it can produce antibody and memory cells. Yes or no? It will not cause disease, but it will produce memory cells. And that memory cells will be responsible for secondary response. And this is the principle of vaccination. Yes or no? Somebody will tell you that vaccination is based on memory of your immune system. Will it be right? Will it be right? Yes. This is all about your humoral immunity. Now, the cell mediated immunity. The cell mediated immunity. Try to understand my point. Cell mediated immunity. First thing is, it is brought about by T lymphocytes. It is brought about by T lymphocytes. Agreed? How many types of T lymphocytes are there? How many types of T lymphocytes are there? There are four. This is known as T suppressor. This is known as T cytotoxic. This is known as T memory and this is known as T helper. Try to understand my point. T cytotoxic, T suppressor, T memory and T helper. Try to understand my point. When the same diagram that we have discussed, I am going to tell you people now. There is a n-T-Zen that is coming and joining the n-T-Zen presenting cell. That can be a lymphocyte. That can be a dendritic cell. That can be a macrophages. And what it do? It is going to activate the T lymphocyte to proliferate. Now, T suppressor, T cytotoxic, T memory and T helper will be produced. Now, try to understand my point. What will be the action of T helper cell? What will be the action of T helper cell? It will activate T cytotoxic cell. Agreed? As well as your plasma cells to produce antibodies. How many types of T cells that you people know? Four types. T suppressor, T helper, T cytotoxic and T memory. Yes or no? Everybody agree, no? There are four. And what is when a n-T-Zen comes, what T helper do? It activate cytotoxic T cell as well as plasma cells to produce antibodies. So, can I say that cell mediated immunity as well as immoral immunity is interconnected? Are they working independently or in, you can say, they are working together? In other words. Agreed? Now you see, if this is happening, what will happen? This cytotoxic T cell will kill the pathogen by creating pores. How? By creating pores. Yes or no? By creating pores. Agreed? One more cell I have told you people who, that cell was creating pore to kill the pathogen. One more cell I have told you. Which cell were there? One more cell were there which were creating pores to kill the cell. Kill the pathogen. Tell me the name. Tell me the name. Anybody? Anybody? Natural killer cells. I have told you no? So if somebody will ask you how T cytotoxic cell is going to kill the pathogen. What will you say? What will you say? It is by creating pores. Agreed? Everyone, what is the function of T cytotoxic? I have made it clear. This is the function of T helper. I have made it clear. Now, what is the function of T separation? See, your immune system should know to work, you can say, in a much aggressive manner. Otherwise, it will start attacking its own cell. So what T suppressor cells do? They keep a check on your immune system so that it can work. It should work, but in a commanded way. Yes or no? Everyone? Yes. What is the role of T memory? The same role that is there for B memory. And what is the role of T helper cells? It activates cell mediated immunity also and it activates humoral immunity also. Now, one question is there for you people. In thymus gland, one hormone is secreted, thymocene. Agreed? Thymocene hormone is secreted. Tell me. Thymocene hormone is secreted. Everyone, what is the function of this thymocene? Thymocene helps in differentiation of T cells. Helps in differentiation of T cells. Means, how these four types of cells are formed? Under the effect of thymocene. Yes or no? Under the effect of thymocene. Yes or no? Everyone? One question I would like to ask you people. If thymus gland degenerates, in that case, which immunity is affected? Which immunity is affected? Tell me dear, whether it is cell mediated, whether it is humoral or both? What will be your take on this? What will be your take on this? Please answer. Can you people hear me? Yes. Ritu is saying both. Anybody else? Anybody else? Aditya, let's see. If thymocene is there, in that case only, all the four types are formed. All the four types are formed. Even T helper is formed by that way only. If thymocene is not there, even T helper will not be formed. In that case, both will be affected. Agreed? Agreed everyone? Now, active and passive immunity. What do you think? What's that? We have two types of immunity, active and passive. What is active immunity? Try to understand my point. Let's discuss something that is going on now only. In case of Corona, what happens? Have you heard about many things like a plasma therapy, self-isolation or you can say COVID recovery, fate? These things we have learned these days? Yes. Try to understand my point. Try to understand my point. What is active immunity? The antibody is formed inside the body of same individual who has infection. If I got infected and antibody is forming inside my body only, I am not taking anything out from outside. That will be active immunity. And if antibody is formed inside, you can say is supplied from outside, is from outside getting my point. In that case, it will be passive immunity. Now you try to tell me over here, question is there. Plasma therapy in a COVID-19 patient is active immunity, 2nd passive immunity. What will be there? Please tell me. Plasma therapy in a COVID-19 patient will be the active immunity or passive immunity. Yes or no? Tell me. Anybody plasma therapy is given? The antibody is taken from some other body and it is given? So it will be active or passive? Yes. It is saying passive. It is passive because if I have COVID, antibody got developed inside my body and somebody is, you can say, not responding to the treatment. In that case, what will happen? Doctor will isolate plasma from my body and give that to the person who is not forming antibody. So the person who got infected, who got infected is getting antibody from somewhere else. That will be a passive immunity. Yes or no? You got difference between them? Active and passive immunity? Somebody is saying active. It is passive dear. Others? Plasma therapy is active or passive? You people should reply. Everyone should reply. Are you getting or not? Please tell me. Either yes or no? Yes. Pranab is saying yes. Aditya is saying yes. Clear. Yes. Now we will talk about some disease. See, what is your health? Immunity people got no? Active, passive, cell mediated, humoral. Okay. Structure of antibody. Those things should be clear because those are the basic things of immunity that you people need to know. Types of antibody, their response, their function that you people need to know. Now human health and disease. What is health? Health is defined as a state of complete physical, mental and social building. Physical health means there is no disease, no fever, no wound, nothing is there. Mental means that person should be very cool, do not have any mental illness and social. If somebody is not behaving socially proper, you can say socially in a proper way, that person is not supposed to be a healthy person. So three components are there. Physical, mental and social. What is the disease? Disease is any deviation from a healthy condition. Disease is any deviation from a healthy condition. What is pathogen? Pathogen is disease causing agent or organism. They are known as pathogens. They are known as pathogens. Now see, disease, types of disease. One is congenital disease and one is acquired disease. Congenital is something that is genetic or present from the birth. And acquired is not present at the time of birth, but it is acquired during the lifetime. Agreed? Try to understand my point. One is hemophilia, sickle cell anemia and Down syndrome. Getting my point? So one question is there. Which of the following is not a congenital disease? One question is there. I am going to ask you people. Question is, which of the following is not a congenital disease? One is sickle cell anemia. Second is Down syndrome. Third is hemophilia. Fourth is cancer. What will you say? One is sickle cell anemia. Another is Down syndrome. Another is hemophilia and one is cancer. Which of the following is not a congenital disease? I think it is cancer. Because cancer is acquired during lifetime. It is not present during the intrauterine life. Yes or no? Everyone? Cancer, yes. Let us see. Now, further, the acquired disease is of following types. One is infectious and one is non-infectious. One is infectious or communicable. Another is non-infectious or non-communicable. Agreed? In infectious, there are two. One is contagious and one is non-contagious. Contagious is corona. Tuberculosis is common cold. They can spread by simple physical means. For being non-contagious and infectious, they require a vector like a mosquito. Malaria, dengue are communicable but non-contagious. It is not going to happen like you went to meet your friend in the hospital and you will develop dengue. No. A mosquito bite should be there. You went to a hospital and you developed malaria. No, not like that. What happens in COVID? Even if you are sitting beside your friend and you can see your friend having COVID-19 virus, it will easily spread to you. By simple physical means, in that case, it is contagious. And if it is not taking place by simple physical means, rather they require a vector, it will be known as what? Non-contagious. See over here. Non-communicable disease can be degenerative, deficiency disorder, allergic disease, hormonal disorder, mental disorder. You can see. What is T-generative? Like heart disease, like epilepsy. Deficiency disorder. It is due to deficiency of some nutrient, like very, very, like night blindness. Allergic disease, asthma or asthma that you people know and hay fever. It is due to allergy of some of the thing. It is due to allergy of some of the thing. And what is hormonal disorder? It is osteoporosis and diabetes. Osteoporosis and diabetes. Diabetes is due to a hormone known as insulin. Yes or no? Everyone? No. Cancer. Try to understand my point. Cancer should not be genetic. That will fall under acquired disease only. Genetic means due to some gene defect that is there. After birth, anything is happening. That will not fall under genetic disease. For cancer, cancer is not a genetic disease. Rather genetic predisposition is there. Like if a mother having breast cancer, in that case, the daughter have more chances of developing that. More chance is there. You cannot say 100% of the cancer you can say is going to be there. So for cancer, genetic predisposition is there. Genetic predisposition is there. Rather it is a genetic disease. It is not a genetic disease. According to the causative organism, communicable diseases are fallen types. One is bacterial disease. Do you know what all bacterial diseases are there? The most common is typhoid fever. The typhoid fever also known as enteric fever. Enterone means what? Enterone means your GIT. Gastrointestinal tract. It is going to infect that only. What is the name of pathogen that is going to cause enteric fever? Please tell me. It is Salmonella typhi. Agreed? Which is the affected organ? A small intestine. What is the mode of transmission? It is fecaloral root. Means buy food. Somebody eats some infected thing. You can say typhoid get develops. It will go out through the feces. The mosquito will sit on this. It will again sit on the food and a normal person will eat this food which is infected by typhoid bacteria through the oral root and they will develop typhoid. So what is the mode of transmission? It is fecaloral root. Somebody will ask you by what root typhoid get develops? What will you say through infected food? Yes or no? Typhoid develops from infected food? Yes or no? Everyone? Yes. Imansu is saying yes. Mode of transmission? How? What is the sign and symptom? Do you people know? What is the meaning of sign and what is the meaning of symptom? What is the meaning of sign and what is the meaning of symptom? You know, somebody goes to a doctor and say, doctor, I have fever. I have headache. What a patient complain? That is a symptom. And after that, doctor writes the investigation. Like doctor writes Vidal test. That is a sign. Like something that is there in your blood. Like leukocyte increased. So what patient tells is symptom and what doctor find through investigation is sign. Okay. So sign and symptom is high fever, 39 to 40 degree Celsius, pain abdomen, constipation because intestine is affected, weakness, headache. Okay. Relative bradycardia. Do you know what is the bradycardia? Usually in fever, your heart rate increases, but in typhoid it decreases. Then the normal fever. Getting my point? So you see over here, what is the test that you people going to suggest in case of Vidal? What is the test you people are going to suggest is Vidal in case of typhoid? Okay. So if somebody will ask you, what is Vidal test? What will you say? What will you say? It is, what have I asked? What is the test for typhoid? What will you say? Vidal test. Agreed? No issues. So salmonella typhi is the bacteria. Okay. A small intestine is the affected organ. Pico oral root is the mode of transmission. And these are the sign. Vidal is the test. Okay. One interesting fact is there. Okay. If somebody have typhoid, bacteria persist in gallbladder. You know what is gallbladder? It is there in the digestive system. I will let you know. Bacteria persist over there in the gallbladder. Agreed? Bacteria persist over there in gallbladder. So even if the person will cure, will get cured, after that through the fecal matter bacteria keep on coming out. And that person if I have typhoid and I got cured, I have a potential of infecting others through this bacteria which is stored in gallbladder. Agreed? This lady, typhoid Mary, she was a cook by profession. She keep on spreading typhoid for a very long time. Okay. There is a story regarding her. One is pneumonia. One is pneumonia. Pneumonia is caused by streptococcus pneumonia and hemophilus influenzae. There are two bacteria that is there. Okay. Which organ is affected? Alveoli of lung. Alveoli of lung. Agreed? No issues? Alveoli of lung will be affected. How it is transmitted if somebody having? You can say pneumonia. Okay. And sputum, do you know what is sputum? After having cough, people use to, you can say throw out some mucous, that is sputum. So through infected sputum, what all things will happen in pneumonia, that person will have fever, chills, difficulty in breathing, cough with sputum. Okay. Do you know what is the meaning of this word? Sinosis. Do you know what is the meaning of the word sinosis? Sinosis means bluish discoloration. Sinosis means bluish discoloration. If somebody will ask you, like you people are going to appear for KVPUI, no defined syllabus is there. Okay. They can ask you simple things. Like if I will say sinosis, it looks like it is a big thing, but it is a very logical thing. Do you know what is the color of venous blood? Venous blood means blood having low oxygen level, bluish. And what is the color of arterial blood? It is bright red. Yes or no? Tell me. What is the color of venous blood? What is the color of venous blood? It is bluish. So try to understand my point. Try to understand my point. The person having infected alveoli. So will oxygen exchange is going to be affected over here. Fluid get filled in alveoli. So this person will get less oxygen or not. If somebody, okay, so bluish red will be there. So what will happen if somebody having oxygen deficiency in the blood, that blood will give appearance like bluish. Okay. So you can say bluish discoloration in the nail bed, in the tongue. At these places it can be seen. So whenever, whenever, getting up on bluish red, I will say, over here. So if somebody will develop pneumonia, you can say bluish discoloration in nail bed, tip of tongue. Okay. That is known as cyanosis. Okay. Tuberculosis. The causative organism is mycobacterium tuberculosis. Okay. And toxin known as tuberculin is released. That all, that's all. Okay. A affected organ is lung. It can be intestine. It can be lymph node. It can be anything. Usually we know that TB is related to lung only. No. It can be there in any part of the body. It can be there in the bone. Okay. Now what happens in TB? Try to understand my point. What happens in TB? Cough is there. Sputum is there. Loss of appetite will be there. Weakness will be there. Okay. Happy people know about this thing. Dots. You can see some of the, you can say, promotion, promotional video regarding dots. This can be asked because these are the general knowledge things. Dots. Anybody know? What is the problem that is going to happen earlier? Okay. The doctor is going to give medicine. Patient is going to take that medicine for few days because treatment of tuberculosis lasts for three to four months. Okay. So, patient is going to take medicine for 15, 20 days. Get relieved. After that, patient starts, he stops the medicine. After getting some relief, patient stops the medicine. Agreed? Because of that, what happens? Multi-drug resistant TB used to develop. So, what happens now? Dots is direct observation therapy in that some of the antibiotic are given, are given under the, you can say, under the observation of the health professional. Like, patient goes to primary health center. Okay. The NM or you can say NM or the doctor, anybody or nurse who is there, that person makes sure that, you can say, patient is going to take the medicine under his observation. Hence, the direct observation therapy. So, if somebody will ask you, dots is related to which disease? Dots is related to which disease? TB. Tuberculosis. Good. Over here. C over here. What is the name of vaccine of tuberculosis? B, C, Z. What is the name of the vaccine of tuberculosis? B, C, G. Bacillus of colomet and borin. They were the scientists who has developed this vaccine. So, for tuberculosis, causative organism, name of the toxin, dots and B, C, G vaccine are the important points. Yes or no? Now, tetanus. Do you people know which organism is going to cause tetanus? Clostridium tetanus. You keep on hearing after having some cut. If some simple cut will be there, your parent is going to give you, you can say, take to the doctor and doctor used to give you one infection, you can say injection. Sorry. What I want to tell, you can say tell. When you have a cut, in that case, doctor is going to give you one, you can say injection. Doctor is going to give you one injection. That injection is there to prevent tetanus only. Yes or no? That injection is going to prevent the tetanus only. It is also known as lockjaw caused by clostridium tetanine. And vaccine is DPT. DPT vaccine is for three diseases. DPT vaccine is for three diseases. Diphtheria, pertusis and tetanus. You see, this is pertusis. This is diphtheria. Okay. So it is for diphtheria, pertusis and tetanus. So if somebody will ask you which vaccine is there for three diseases, what will you say? DPT. Remember these things. Viral disease. The common cold that you people used to develop is caused by rhinovirus. Influenza is caused by myxovirus. What we make a mistake, usually we write over here, influenza is caused by hemophilus influenza. It is wrong. Because hemophilus influenza is going to cause pneumonia. So influenza is caused by which virus? Myxovirus. You people will remember these things. See, myxovirus. Swine flu is caused by H1N1 and avian influenza is caused by H5N1. Remember these things. You can write it down. That much is not needed for you people. See over here. H stands for heme aglutinin and neuraminidase. They are the glycoproteins present on the surface. Heme aglutinin and neuraminidase. Because of that only H and N is written. Because of these two enzymes. This thing you people can understand. They are the glycoproteins present on the surface of virus. So there are many groups H1, H5, H9 like that. So we can hear these things. You can read these things in newspapers. That swine flu is caused by S5N1. Avian influenza that is bird flu is caused by H5N1. Yes or no? Agreed? Everyone? You understood? H and N, in KBBY they can ask you. Getting my point? Because these things you people keep on reading in newspaper. And they think that if you are going to be a scientist and you think like that you should be aware of these general things. So heme aglutinin and neuraminidase. They are the glycoproteins present on the surface. Based on that only we decide H1N1 and H5N1. They are very important. These are there. A few more things we will discuss in the next class. Okay. I hope you people have understood. Yes, I will share. I will share in half an hour. Okay. I will share the notes and if you have any doubt you can ask me. I think my number is there on the group also. So you people can ask. Okay. Bye. Bye everyone.