Human Health and Diseases PDF

Human Health and Diseases © 2022, Aakash BYJU'S. All rights reserved Key Takeaways Health 1 2 Immunity 3 Innate 4 Acquired Lymphoid organs Primary lymphoid organs Secondary lymphoid organs © 2022, Aakash BYJU'S. All rights reserved Factors affecting health Vaccination Types 5 Importance Immunisation...

Human Health and Diseases © 2022, Aakash BYJU'S. All rights reserved Key Takeaways Health 1 2 Immunity 3 Innate 4 Acquired Lymphoid organs Primary lymphoid organs Secondary lymphoid organs © 2022, Aakash BYJU'S. All rights reserved Factors affecting health Vaccination Types 5 Importance Immunisation 6 7 Bacterial diseases Typhoid Fungal diseases 8 Pneumonia 9 Helminthic diseases Ringworm Ascariasis Protozoan diseases Malaria Amoebiasis © 2022, Aakash BYJU'S. All rights reserved 10 Filariasis 11 Viral diseases Common cold Immunodeficiency 12 13 Tumour cell vs normal cell HIV/AIDS Life cycle 14 Stages of infection Modes of transmission Prevention © 2022, Aakash BYJU'S. All rights reserved 15 Causes of cancer 16 17 Treatment of cancer Addiction Tumour & types Stages of cancer 18 19 Classes of drugs 20 Opioids Cannabinoids Cocaine © 2022, Aakash BYJU'S. All rights reserved Tobacco addiction 21 Effects of tobacco Diseases Withdrawal symptoms 22 23 Summary © 2022, Aakash BYJU'S. All rights reserved Adolescence Good Humor Hypothesis Health, for a long time, was considered as a state of body and mind where there was a balance of certain ‘humors’ (liquids). Blood Yellow Bile Black Bile Phlegm © 2022, Aakash BYJU'S. All rights reserved Humors = Fluids in the body It was believed that increase of black bile in the body increases fever. Blood Circulation Hypothesis  In 16th century, William Harvey, an English physician, conducted a series of experiments to understand blood and its circulation.  He provided many important insights into the blood circulation system.  Research led to the understanding that blood circulation makes sure that the right body temperature is maintained.  Consequently, “good humor hypothesis” of health was disregarded. © 2022, Aakash BYJU'S. All rights reserved Health Mental well-being  Since then, great works of pioneers and their discoveries have changed the definition of health.  According to WHO, health is the state of complete physical, mental and social well-being and not merely the absence of disease and infirmity. Health Physical well-being Absence of diseases © 2022, Aakash BYJU'S. All rights reserved Social well-being Health Consequences of good health High efficiency at work © 2022, Aakash BYJU'S. All rights reserved Low maternal & infant mortality Economic growth Increased longevity of individuals Factors Affecting Health Genetic factors  Parents pass on their traits through genetic materials to offspring. Mother Father Offspring © 2022, Aakash BYJU'S. All rights reserved  Sometimes, genetic material undergoes some changes due to mutation which can be harmful. Mother Father Offspring with defective gene Factors Affecting Health Genetic factors  The mutations that are inherited by offspring can lead to genetic disorders. A disease/disorder can be caused in an individual due to a change in the DNA sequence inherited from parents. Example: Down’s syndrome, Sickle-cell anaemia, etc. © 2022, Aakash BYJU'S. All rights reserved Factors Affecting Health Lifestyle  Lifestyle includes food and water we take, rest and exercise we give to our bodies, habits that we have or lack, etc.  For example, good personal hygiene.  Poor hygiene affects health and can make an individual sick. © 2022, Aakash BYJU'S. All rights reserved Sedentary lifestyle Sugary drinks Junk food Factors Affecting Health Infections Pathogen An infection is the invasion of an organism's body tissues by diseasecausing agents known as pathogens. Human body has various mechanisms to tackle infectious diseases. © 2022, Aakash BYJU'S. All rights reserved Pathos Refers to ‘disease’ Gen Refers to ‘producing’ Immunity Innate immunity  It is an ability to fight pathogens which is present since birth.  It is non-specific as it fights against all kinds of pathogens.  It is non-adaptive. © 2022, Aakash BYJU'S. All rights reserved The ability of the host to fight the disease-causing organisms, conferred by the immune system is called immunity. Based on how it is obtained it is categorised into two types. Acquired immunity  It is an ability to fight pathogens which is developed over a period. Immunity Types of immunity Innate 1st Acquired 1st categorisation line of defence Physical barriers Humoral Cell mediated Physiological barriers 2nd categorisation 2nd line of defence Cellular barriers Cytokine barriers © 2022, Aakash BYJU'S. All rights reserved Active Passive Innate Immunity When a pathogen attacks, it faces the 1st line of defence which comprises of different barriers. Physical barriers Physiological barriers  These provide mechanical defence against microbes.  These include skin and mucous membrane.  Mucus membrane forms the coating on the epithelium lining of respiratory, gastrointestinal and urogenital tracts.  It traps the microbes. © 2022, Aakash BYJU'S. All rights reserved   Our whole body is covered by skin. Skin acts as shield and prevents pathogens from entering our body.  Physiological barriers provide harsh conditions to microbes such that they cannot survive.  Acid in stomach, saliva in mouth and tears kill these microbes.  Tears and saliva have lysozyme enzyme which destroys them. Innate Immunity 2nd line of defence Cellular barriers Human body is guarded by many cells which fight against pathogens. These cells form the second line of defence. © 2022, Aakash BYJU'S. All rights reserved Cytokine barriers If pathogens are able to cross all these barriers and are successful in infecting the cells, then our body uses a special kind of immunity known as cytokine barrier. Innate Immunity Cellular barriers  The first type of cellular barriers are neutrophils.  They are also called polymorphonuclear leukocytes (PMN, PML, or PMNL) because of varying shape of their nucleus. (PMNL) Neutrophils © 2022, Aakash BYJU'S. All rights reserved Helps in phagocytosis of invading bacteria Innate Immunity Cellular barriers  The second type of cellular barriers are monocytes.  Monocytes transform into third type of cells called macrophages.  They can detect the region of infection.  Macrophages have the ability to phagocytose pathogens and digest them. These cells can also release cytokines. Macrophages Monocytes  Give rise to macrophages in tissues © 2022, Aakash BYJU'S. All rights reserved   Phagocytosis of the invading bacteria Release cytokines Innate Immunity Cellular barriers   The fourth type of cellular barriers are killer cells. These cells can release chemicals which kill the bacteria as well as the infected cells. Natural killer cells  © 2022, Aakash BYJU'S. All rights reserved Kill the invading bacteria Innate Immunity Cytokine barriers   © 2022, Aakash BYJU'S. All rights reserved These are certain proteins produced by infected cells, which protect non-infected cells from further infection. Example - Interferons produced by virus infected cells. Interferons stimulate the synthesis of certain proteins that inhibit the production of viral proteins which are required for their replication. Acquired Immunity     Pathogen specific Initiates primary response on encountering a pathogen for the first time Effector B and T cells are produced to counter the infection Memory B and T cells are also produced o Generate a secondary/anamnestic response © 2022, Aakash BYJU'S. All rights reserved Acquired immunity Humoral/ antibody mediated immunity Cell mediated immunity (Provided by B-cells) (Provided by T-cells) Acquired Immunity Humoral immunity Pathogens (antigen) enter the cell B-lymphocytes get activated Antigens    Some B-cells differentiate into plasma cells to secrete antibodies against pathogen © 2022, Aakash BYJU'S. All rights reserved Undifferentiated B-cells become memory cells to protect against future attacks  Antigen derived from - Antibody + generating Generally, large molecules Mostly proteins or polysaccharides on cell walls of bacteria or coats of virus Structures like pollen grains, white of an egg, shell fish, dust, blood cells of other organisms , drugs and chemicals can also act as antigens. Humoral Immunity Antibody  Each antibody and its clones are specific to a particular antigen. There are several antibodies of different specificity referred to as polyclonal response. © 2022, Aakash BYJU'S. All rights reserved C -s- | s- Since it’s a protein, it has amino end (N terminal) and carboxyl end (C terminal). | -s- | s-  C -s-s-s-s| -s- | s-  Immunoglobulin is a Y shaped protein consisting of four peptide chains. |  These are also called immunoglobulins (Ig) as these are globulin (protein) molecules helping in immune response. -s- | s-  Plasma B cells release soluble protein molecules called antibody. C |  C Immunoglobulin (Ig) Humoral Immunity Antibody The lighter peptide chain is linked to the heavy peptide chain via single disulphide bond. © 2022, Aakash BYJU'S. All rights reserved -s- | s- C Light chain (L2) | There are total 16 disulphide bonds in the entire structure. C | -s- | s-  Heavy peptide chains are connected to each other via two disulphide bonds. -s-s- | -s- | s-  Therefore, structurally, an antibody is denoted as H2L2. -s- | s-  Heavy chain (H2) C |  Immunoglobulin has two heavy peptide chains denoted as H2 and two light peptide chains denoted as L2. -s-s-  C Immunoglobulin (Ig) Humoral Immunity Antibody      Antibody recognizes and binds to molecular shapes on antigen called epitopes. Specific binding Epitopes whose shape doesn’t complement with the antigen binding site of the antibody cannot be recognized by the antibody. Non - specific binding Antibody fixes to the epitope which is complementary to the antigen binding site of the antibody. Antibodies are very specific to an antigen. Different types of antibodies are IgA, IgG, IgD, IgM and IgE. © 2022, Aakash BYJU'S. All rights reserved Pathogen Acquired Immunity Cell-mediated immunity Bone marrow produces immature lymphocytes Travel to thymus and differentiate into Tlymphocytes Helper T-cell - Stimulate B-cells to produce antibodies and killer T-cells to destroy non-self cells Cytotoxic/Killer T-cell - Secrete perforins which causes the cells to burst by perforating cell membrane and allowing entry of excess water Suppressor T-cell – Suppress the function of cytotoxic T-cells and helper cells to protect body’s own cells T-lymphocytes migrate to lymphoid tissue and differentiate into one of the four: © 2022, Aakash BYJU'S. All rights reserved Memory T-cell - Remain in lymphatic tissue and recognize invading antigens even after several years of first encounter Mechanism of Detecting Foreign Antigens Major Histocompatibility Complex  The cells present antigens with the help of protein complex called MHC.  MHC is present on all cells of our body.  T-cells come in contact with the MHC of cells and decide whether a given antigen belongs to the body or not. MHC  If cell is damaged or attacked by a pathogen, it presents antigen on MHC and T-cells elicit immune response against the pathogen.  MHCs are encoded by several genes located on chromosome 6. © 2022, Aakash BYJU'S. All rights reserved  MHCs are also referred to as Human Leukocyte Antigen (HLA) Mechanism of Detecting Foreign Antigens Major Histocompatibility Complex Whenever macrophages and dendritic cells encounter pathogens, they present antigen on their surface with the help of major histocompatibility complex. Macrophage Dendritic cell © 2022, Aakash BYJU'S. All rights reserved Pathogen Pathogen Antigen presenting macrophage cell Antigen presenting dendritic cell Organ Transplantation  Organs like eyes, liver, heart and kidneys need to be transplanted in case they fail to function satisfactorily.  So, the healthy organ from a suitable donor is transplanted into the recipient.  When the T-cells come close to the cells of the new organ, they check whether the peptide is self or non-self.  When the graft (transplanted tissue/organ) has MHC which is non-self, the Tcells treat it as antigen and reject it by raising immune response. GRAFT REJECTION Living donor T - cell Recipient Graft cell © 2022, Aakash BYJU'S. All rights reserved Organ Transplantation  Tissue matching (MHC matches) and blood group matching are essential before undertaking any graft/transplant.  The body is able to differentiate ‘self’ and ‘non-self’ and the cellmediated immune response is responsible for the graft rejection.  Even after tissue and blood group matching, the patient has to take immunosuppressants all his/her life.  When a patient takes immunosuppressants, his immunity levels become lower. © 2022, Aakash BYJU'S. All rights reserved Vaccination  Vaccination is the administration of vaccine in order to stimulate the immune system against the pathogen, thereby developing protection from a disease.  The principle of vaccination is based on the property of ‘memory’ of the immune system.  They also generate memory T and B-cells that recognise the pathogen quickly on subsequent exposure.  Vaccines stimulate the production of antibodies and provide immunity against diseases whenever there is an infection in the future. © 2022, Aakash BYJU'S. All rights reserved Vaccines Types of vaccines Antigen only Antigen Only © 2022, Aakash BYJU'S. All rights reserved Killed/Weakened pathogen Killed/ Weakened Pathogen RNA RNA Vaccination  When the body is vaccinated against a pathogen, a primary immune response is generated which creates memory B cells.  Memory B cells are then able to mount a defence attack against an actual pathogen – this is the secondary immune response. Level of antibodies in blood Primary immune response Secondary immune response Time First exposure to pathogen Secondary exposure to pathogen Graph showing antibody response to pathogens © 2022, Aakash BYJU'S. All rights reserved Importance of Vaccination  It protects the population and also leads to herd immunity. ○ Herd immunity is a form of protection from infectious diseases. ○ When sufficient percentage of a population becomes immune to an infection, (through vaccination or previous infections), it reduces the likelihood of infection in individuals who cannot get vaccinated for medical reasons. ○ When a lot of people in the population are not vaccinated, the whole unvaccinated population is susceptible to the disease. ○ In such a scenario, people who cannot be vaccinated due to medical reasons are more likely to get infection and suffer serious disease. © 2022, Aakash BYJU'S. All rights reserved Importance of Vaccination Myths Facts Vaccines cause autism There's no evidence or link between any vaccine and autism Vaccines contain dangerous toxins Some vaccines have very low levels of toxins, which is harmless Vaccines can infect us with the disease we are trying to prevent Symptoms appear after vaccination because of our immune system’s response against it and not the disease © 2022, Aakash BYJU'S. All rights reserved Adaptive Immunity Active immunity  Active immunity comes into play when host is exposed to antigens.  Antibodies are produced.  It is slow but long lasting. 1  Natural Infectious agents gaining access into body naturally- natural active immunity © 2022, Aakash BYJU'S. All rights reserved 2  Artificial Resistance induced by injecting vaccine- artificial active immunity Adaptive Immunity Passive immunity  The ready-made antibodies are administered into the body of a patient to protect against foreign agents.  Passive immunity is fast but does not last for a long time. 1 Natural  The foetus receives Ig G antibodies from the mother through the placenta during pregnancy.  The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (Ig A) to protect the infant.  These are some examples of natural passive immunity. Ig G antibody through placenta © 2022, Aakash BYJU'S. All rights reserved Ig A antibody through colostrum Adaptive Immunity Passive immunity Artificial  Artificial passive immunity is the resistance passively transferred by administration of pre-made antibodies like in the case of anti-venom vaccine.  In the process of vaccination, a preparation of vaccine containing antibodies are introduced into the body. Pre-made antibody administration © 2022, Aakash BYJU'S. All rights reserved Immune System Lymphoid organs  Organs where origin and/or maturation and proliferation of lymphocytes occur.  Lymphocyte is a type of white blood cell that is the part of the immune system.  Lymphoid organs are involved in the immune system. Lymphoid organs Based on the role in the development of the immune cells Primary lymphoid organs © 2022, Aakash BYJU'S. All rights reserved Secondary lymphoid organs Primary Lymphoid Organs Primary lymphoid organs are the organs where immature lymphocytes are produced and are differentiated into antigen-sensitive lymphocytes. Primary lymphoid organs Bone marrow © 2022, Aakash BYJU'S. All rights reserved Thymus Primary Lymphoid Organs Bone marrow  It is the main primary lymphoid organ.  It is the site of lymphocytes production and self renewal.  It provides micro-environments for the development and maturation of the lymphocytes. Bone marrow  The cells, molecules, and structures (such as blood vessels) that surround and support other cells and tissues is called microenvironment.  It is located in most of the bones.  It is considered equivalent to Avian Bursa of Fabricius.  Some lymphocytes migrate from bone marrow to thymus through blood. © 2022, Aakash BYJU'S. All rights reserved Bone Primary Lymphoid Organs Thymus  It is a bilobed organ.  It is located near heart, beneath the breastbone.  It provides micro-environment for the development, maturation and selection of some lymphocytes.  It is very large in size at time of birth, size starts reducing after puberty.  It is the site where T-lymphocytes mature. © 2022, Aakash BYJU'S. All rights reserved Thymus Secondary Lymphoid Organs ❖ Naïve lymphocytes move to secondary lymphoid organs which is the training ground of these lymphocytes, arriving from primary lymphoid organs. ❖ Secondary lymphoid organs provide antigen to the lymphocytes for the interaction. Antigen Lymphocytes © 2022, Aakash BYJU'S. All rights reserved Secondary Lymphoid Organs  These lymphocytes then proliferate and increase in number when a pathogen attacks.  They increase in number to fight against the pathogens.  Mature lymphocytes differentiate into effector cells and elicit immune response.  Effector lymphocytes -They identify antigens and kill the pathogen. © 2022, Aakash BYJU'S. All rights reserved Secondary Lymphoid Organs Organs where mature lymphocytes interact with the antigen and then proliferate to become effector cells. Tonsils Lymph nodes Spleen Appendix © 2022, Aakash BYJU'S. All rights reserved Peyer’s patches Secondary Lymphoid Organs Tonsils Spleen  These are two round lumps.  It is a large bean shaped organ.  Location - Either side of back throat  Location - High, left side of abdominal cavity.  They provide 1st line of defense against ingested or inhaled pathogens (They are the first ones to attack the pathogen).  It contains lymphocytes and phagocytes (celleating cells).  It acts as filter of blood and traps blood-borne microorganisms.  It is a large reservoir of erythrocytes (RBC).  It is commonly referred to as graveyard of RBCs. © 2022, Aakash BYJU'S. All rights reserved Secondary Lymphoid Organs Appendix Peyer’s patches  It is a finger like structure.  They are patch like structures.  It is located at the junction of small intestine and large intestine.  They are located in the mucosal layer of small intestine, usually in the ileum area.  The function of appendix is unclear.  They trap microorganism which enter through digested, absorbed food.  Trapped antigen stimulates and activates the lymphocytes present there. © 2022, Aakash BYJU'S. All rights reserved Secondary Lymphoid Organs Lymph nodes  They are small, solid node like structures.  Location - Various points along the lymphatic system.  Traps microorganism which enter lymph and tissue fluid.  Trapped antigen then stimulates and activates lymphocytes present there  Lymph nodes have a huge, extensive network in the entire body which constitutes an entire system called lymphatic system. © 2022, Aakash BYJU'S. All rights reserved Immune Tissue Mucosa associated lymphoid tissue  Mucosa-associated lymphoid tissue (MALT) specializes in mucosal defense and is present on the body's mucosal surfaces.  It constitutes 50% of lymphoid tissue in human body.  Location - Lining of major tracts o o o MALT (50%) Respiratory tract Digestive tract Urogenital tract © 2022, Aakash BYJU'S. All rights reserved Tissues of immune system Immunisation Active immunity It is a process by which an individual's immune system becomes equipped with antibodies against a pathogen. Natural Artificial Active immunisation Exposure to an antigen triggers the immune system to produce antibodies in the host body. Certain vaccines belong to this category. © 2022, Aakash BYJU'S. All rights reserved Types of adaptive immunity Passive immunity Natural Artificial Passive immunisation Preformed antibodies are injected into the body to provide a quick immune response. Vaccines made from toxins belong to this category. Passive Immunisation  It is needed when a person has insufficient time to produce antibodies against a high risk of infection.  For example, a bite from a venomous snake introduces deadly toxins inside the victim. o This can have dangerous effects and can be fatal in some cases. © 2022, Aakash BYJU'S. All rights reserved Passive Immunisation  In such cases, an injection with preformed antibodies against the snake venom is given to the patient. These antibodies neutralize the venom and reduce its effects.  These antibodies are usually generated in horse or rabbits, collected and kept ready for emergency use. © 2022, Aakash BYJU'S. All rights reserved Allergy Dust Pollens The exaggerated response of the immune system to certain antigens present in the environment is called allergy. Substances which trigger such exaggerated response Animal dander Allergens Certain medicines © 2022, Aakash BYJU'S. All rights reserved Food items Mites Allergy Symptoms Rash Watery eyes Running nose, sneezing Sore throat, difficulty in breathing © 2022, Aakash BYJU'S. All rights reserved Allergy Diagnosis  Patient is exposed to or injected with very small doses of possible allergens, and the reactions are studied. Treatment  The use of drugs like antihistamine, adrenaline and steroids quickly reduce the symptoms of allergy.  These drugs decrease inflammation or act against the histamines. © 2022, Aakash BYJU'S. All rights reserved Autoimmune Diseases  In an autoimmune disease, the immune system mistakes part of the body like joints or skin as foreign and starts attacking them (self-cells).  Example: Rheumatoid arthritis o It is inflammation of joints. o It worsens with age. o Its symptoms are joint pain and stiffness. © 2022, Aakash BYJU'S. All rights reserved Diseases  Condition where functioning of one or more organs of body is adversely affected.  It presents with different signs and symptoms. Types of diseases Non-infectious diseases  Do not spread  Also known as non-communicable or non-contagious diseases e.g.: o Cancer o Diabetes o Genetic disorders o Allergy o Autoimmune diseases, etc.. © 2022, Aakash BYJU'S. All rights reserved Infectious diseases  Spread from one person to another  Also known as communicable or contagious diseases  Caused by pathogens Disease Bacteria Fungi Pathogens Virus Protozoa Helminths © 2022, Aakash BYJU'S. All rights reserved Bacterial Diseases Typhoid Pneumonia Plague Dysentery Tetanus © 2022, Aakash BYJU'S. All rights reserved Tuberculosis Cholera Diphtheria Typhoid Causative agent - Salmonella typhi Mode of transmission Symptoms  Salmonella can be transmitted through contaminated food and water.  Sustained fever (39-40OC)  Insects like flies can be carriers for the Salmonella.  Flies sitting on human faeces can pick up these bacteria. o When the same fly sits on food, it transmits bacteria to food, thereby acting as a carrier  Migrates to different organs through blood  Weakness  Stomach pain  Constipation  Headache  Loss of appetite  Intestinal perforation or death may occur in severe cases Test  Widal test © 2022, Aakash BYJU'S. All rights reserved Pneumonia Causative agent - Bacteria like Streptococcus pneumonia, Haemophilus influenzae Symptoms Mode of transmission  By inhalation of droplets/aerosols released by an infected person  By sharing glasses and utensils with infected person  Hospitalised patients and people with weak immune system are affected by pneumonia more often.  Alveoli of the lungs are infected and get filled with fluid leading to respiratory problems  Fever  Chills  Cough  Headache  Lips and nails may turn grey to bluish in severe cases © 2022, Aakash BYJU'S. All rights reserved Fungal Diseases Mucormycosis Fungal acne Candidiasis © 2022, Aakash BYJU'S. All rights reserved Ringworm Aspergillosis Athlete’s foot Ringworm  Mycelia of pathogenic fungi grown on epidermis of the skin  Diagnosed by scraping the lesion and observing under the microscope Transmission: o Through direct contact with an infected person or pet o By sharing of combs, bath towels, nail cutters etc. with infected person Treatment: o o Topical creams, antifungal soaps and shampoos Oral antifungal drugs are also given in severe cases © 2022, Aakash BYJU'S. All rights reserved Causative genera  It is caused by three genera of fungi o Microsporum o Trichophyton o Epidermophyton Symptoms  Fungi specially infect areas like neck, armpit, trunk, groin, scalp and under the nails  Circular, red, flaky, itchy and burning rash  Appearance of dry, scaly lesions on various parts of the body such as skin, nails and scalp Ringworm Variations  Tinea pedis o Also called Athlete’s foot o Commonly seen in sportsmen who wear tight shoes o Appears as red flaky rash between the toes © 2022, Aakash BYJU'S. All rights reserved  Tinea cruris o Leads to pain in groin and perineum  Tinea barbae o Affects bearded areas of the face and neck Helminthic Diseases Ascariasis Filariasis Enterobiasis Trichuriasis Schistosomiasis Loiasis © 2022, Aakash BYJU'S. All rights reserved Ascariasis  Ascaris (roundworm) is a parasitic nematode which infects small intestines.  It is also known as intestinal worm.  This disease is found in tropical countries with poor hygiene and sanitations.  The worms live and mature in the small intestine.  They grow to an extent that they block the intestinal passage. Causative organism Ascaris lumbricoides Ascaris © 2022, Aakash BYJU'S. All rights reserved Ascariasis Transmission  Infected human’s faeces containing Ascaris eggs can get mixed with the soil due to Oral faecal poor sanitary facilities. route  Unwashed fruits or vegetables that are grown in contaminated soil can transmit the ascariasis eggs when healthy humans consume them. Infected host Vegetables grown in fields contaminated with faeces Flies Unwashed Hands New host Contaminated water © 2022, Aakash BYJU'S. All rights reserved Ascariasis Symptoms Treatment  Anti-helminthic drugs like Albendazole and Mebendazole are given to kill worms  In severe case, worms block intestinal passage. They are surgically removed. Abdominal and muscle pain Presence of Presence of worms worms and and eggs ineggs feces in feces Abnormal Abnormal weight weightloss loss  Ascariasis can be prevented by practicing proper hygiene and sanitation. Anaemia © 2022, Aakash BYJU'S. All rights reserved Fever Blockage of intestinal passage Filariasis Causative organism The parasitic worms live in the lymphatic system (lymph nodes/lymphatic vessels). Wuchereria bancrofti and Wuchereria malayi Lymphatic system Also called Elephantiasis, due to its resemblance to leg of an elephant © 2022, Aakash BYJU'S. All rights reserved Filariasis Transmission Treatment  Through the bite of female mosquito vectors. E.g.: Culex mosquito  Anti-helminthic drugs are given to kill the worms. Symptoms  They reduce the density of early stage (microfilariae) in blood stream.  Slowly developing chronic infection and inflammation of organs  Swelling of legs, scrotum and other parts  Usually affect the lymphatic vessels  Thus, they help prevent spread of parasites to mosquitoes.  In severe cases, where worms block the intestines, worms are surgically removed. © 2022, Aakash BYJU'S. All rights reserved Protozoan Diseases There are many protozoan pathogens that only infect humans and can be deadly. Babesiosis Malaria Amoebiasis Leishmaniasis Cryptosporidiosis Trypanosomiasis © 2022, Aakash BYJU'S. All rights reserved Malaria Causative organism Plasmodium Female Anopheles mosquito  Plasmodium is transmitted through the bite of female Anopheles mosquito. © 2022, Aakash BYJU'S. All rights reserved Malaria Plasmodium are of 4 types:  Plasmodium vivax Common Plasmodium falciparum Plasmodium ovale Plasmodium malariae Plasmodium vivax  Plasmodium ovale - Rare  Plasmodium falciparum Most dangerous, can be fatal  Plasmodium malariae  It involves two hosts - human and mosquito. © 2022, Aakash BYJU'S. All rights reserved Lifecycle of Plasmodium  Infected mosquito sits on human host to suck blood. © 2022, Aakash BYJU'S. All rights reserved  Malarial parasite Plasmodium are found in the salivary glands of mosquito as sporozoites. Lifecycle of Plasmodium  Mosquito injects Plasmodium sporozoites into the human body  Injected sporozoites reach bloodstream  From the bloodstream, sporozoites travel to the liver. © 2022, Aakash BYJU'S. All rights reserved Lifecycle of Plasmodium  The sporozoites now infect the liver cells and reproduce asexually  Sporozoites multiply inside liver cells and develop into schizonts. © 2022, Aakash BYJU'S. All rights reserved Lifecycle of Plasmodium  Each sporozoite multiplies to form schizonts that matures to form ˜ 40,000 merozoites.  Liver cells rupture over a period of several weeks to release merozoites © 2022, Aakash BYJU'S. All rights reserved  Merozoites released from liver re-enter the bloodstream.  At this stage, merozoites are also called cryptozoites. Lifecycle of Plasmodium  The merozoites infect the RBCs and reproduce asexually.  The released parasites then infect other new RBCs. © 2022, Aakash BYJU'S. All rights reserved  The merozoites mature and multiply to form blood-stage schizonts. Lifecycle of Plasmodium  The merozoites develop sexually into gametocytes in the RBCs.  The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. © 2022, Aakash BYJU'S. All rights reserved  When a female Anopheles mosquito bites an infected person, these parasites enter the mosquito’s body and undergo further development, the mosquito takes in the Plasmodium gametocytes along with the blood. Lifecycle of Plasmodium  These gametocytes enter the mosquito gut.  These zygotes develop and mature in the mosquito gut to finally form sporozoites. © 2022, Aakash BYJU'S. All rights reserved  Then the male and the female gametocytes fuse to form zygotes i.e., they reproduce sexually. Lifecycle of Plasmodium  The sporozoites formed then enter the salivary glands of the mosquito.  Then these sporozoites are injected into the human body during the next blood meal i.e., when the mosquito bites another human being. © 2022, Aakash BYJU'S. All rights reserved  Same mosquito injects the sporozoites into uninfected human and the cycle continues. Malaria Headache Fatigue Symptoms Fever Nausea Muscle ache © 2022, Aakash BYJU'S. All rights reserved Vomiting Chills Amoebiasis  Amoebiasis is caused by a protozoan. Causative organism Entamoeba histolytica Transmission  House flies act as mechanical carriers (transfer parasites from faeces to food and water).  Drinking contaminated water and food infects the person. © 2022, Aakash BYJU'S. All rights reserved Amoebiasis Symptoms Effect  Entamoeba histolytica is a protozoan parasite in the large intestine of human which causes amoebiasis (amoebic dysentery). Fatigue Loose stools with blood and mucus Large intestine Stomach ache © 2022, Aakash BYJU'S. All rights reserved Constipation Viral Diseases  Many viruses causes various diseases - Mild to severe. Common cold Hepatitis COVID-19 Flu Mumps  People sneezing and coughing without covering the mouth leads to spread of droplets that carry viruses. Measles Polio Rabies Rubella Smallpox © 2022, Aakash BYJU'S. All rights reserved Common Cold Causative organism Rhinovirus  Rhinovirus affects nasal and respiratory tract (not the lungs). Transmission  Common cold virus cannot be treated with any medications.  Contact with infected surfaces like mouse, keyboard, pen books, cups etc  Aerosols from an infected person Symptoms  Cough  Sore throat  Headache  Fatigue  Nasal congestion and runny nose  Hoarseness in voice © 2022, Aakash BYJU'S. All rights reserved Immunodeficiency Inability of the immune system to fight against infectious diseases Types Immunodeficiency Primary or congenital immunodeficiency © 2022, Aakash BYJU'S. All rights reserved Secondary or acquired immunodeficiency  Congenital and is caused by genetic factors  Example - SCID (Severe combined immunodeficiency) Acquired and caused due to external factors Example – HIV/AIDS HIV/AIDS  AIDS or acquired human immunodeficiency syndrome is caused by the infection of human immunodeficiency virus.  HIV causes AIDS.  HIV is a virus that infects the macrophages and T lymphocytes (since it affects and damages the immune cells), thus it leads to immunodeficiency.  However, all HIV positive individuals do not have AIDS.  All individuals with AIDS are HIV positive. Macrophage Human immunodeficiency virus - HIV © 2022, Aakash BYJU'S. All rights reserved T-lymphocyte HIV/AIDS  Initial HIV infection itself does not cause AIDS.  HIV progresses in three different stages – acute, chronic and AIDS.  Thus, AIDS is the ultimate stage of HIV infection.  So, a patient who is HIV positive might be in any of the 3 stages, not essentially AIDS. Acute HIV © 2022, Aakash BYJU'S. All rights reserved Chronic HIV AIDS Human Immunodeficiency Virus Structure Reverse transcriptase (present within the capsid) Viral envelope (outermost layer) Glycoprotein (spike - like structure, embedded in envelop) Capsid (made up of protein, present within the envelop ) ssRNA (HIV is a type of retrovirus as it contains two single stranded RNA) © 2022, Aakash BYJU'S. All rights reserved Reverse Transcriptase – Function  The process of formation of DNA from RNA is called reverse transcription.  The enzyme reverse transcriptase is used in this process.  This helps in the formation of viral DNA within the host cell. DNA RNA Transcription Reverse transcription © 2022, Aakash BYJU'S. All rights reserved Human Immunodeficiency Virus - Life Cycle Surface of the T-cells have receptors Viral RNA gets enclosed in capsid and then into the new viral envelope Glycoprotein of HIV virus binds with receptors present on the surface of Tlymphocytes Viral RNA translates to form structural proteins Capsid uncoats and the virus then fuses with the plasma membrane of T-cells Viral RNA is produced by means of transcription which then moves into the cytoplasm of T-cell RNA transcriptase facilitates conversion of viral RNA to DNA Viral DNA moves into the nucleus and merges with the host genome © 2022, Aakash BYJU'S. All rights reserved No. of T-lymphocytes/Immunity Human Immunodeficiency Virus – Life cycle  After the new viruses are formed, they attack and kill the T-lymphocytes.  As a result, T-lymphocyte count drops in the blood, thus weakening the immunity. © 2022, Aakash BYJU'S. All rights reserved Secondary Lymphoid Organs HIV progression Acute HIV  T lymphocyte count decreases  Occurs after first few weeks of infection  Develop flu like symptoms Acute HIV infection Before HIV infection Infection  Initial stage Weeks to months T-lymphocyte Years HIV  During this phase, the HIV multiplies rapidly and spreads throughout the body, destroying some lymphocytes.  HIV level in blood is very high in this stage, thus increasing the chances of transmission. © 2022, Aakash BYJU'S. All rights reserved HIV/AIDS – Stages of Infection HIV progression Chronic HIV  Asymptomatic stage Acute HIV infection Before HIV infection Chronic HIV infection Infection  Lasts for several years, ~ 10 years Weeks to months T-lymphocyte Years HIV  During this stage, the HIV continues to multiply in the blood, but at a very low rate.  The HIV levels overall drop considerably.  However, over time, levels of T-lymphocytes drop too. © 2022, Aakash BYJU'S. All rights reserved HIV/AIDS – Stages of Infection HIV progression AIDS  The body is prone to several infections due to weak immune system.  (AIDS-defining illnesses are seen.) Acute HIV infection Before HIV infection Chronic HIV infection AIDS Infection  The last stage is Acquired immunodeficiency syndrome. Weeks to months T-lymphocyte Years HIV  The last stage of HIV infection is AIDS (acquired immunodeficiency syndrome).  In this stage, the immune system is the weakest. Thus, it is prone to several infections.  Some of these infections are even fatal.  These infections are called opportunistic infection or AIDS defining illnesses. © 2022, Aakash BYJU'S. All rights reserved HIV/AIDS – Stages of Infection AIDS – defining illness (common diseases that people suffering from AIDS become susceptible to)  Candidiasis : Fungal infection  Mycobacterium avium complex : Bacterial infection  Toxoplasmosis: Parasitic infection (Toxoplasma) © 2022, Aakash BYJU'S. All rights reserved HIV – Modes of Transmission Infectious fluids HIV can spread through different body fluids from the infected people. E.g. - blood, semen, rectal fluid, pre-seminal fluid, breast milk and vaginal fluid. Susceptible areas Mucous membrane  These fluids have to come in contact with specific susceptible areas in the body to transmit HIV. Vaginal Oral Tip of penis © 2022, Aakash BYJU'S. All rights reserved Anal  The mucous membranes of mouth, anus and sex organs are the susceptible areas of transmission.  This kind of transmission through body fluids, is common with breast milk and also through sexual fluids during sex. HIV – Modes of Transmission Susceptible areas Injuries  HIV can get in through open cuts either through sex organs or any other part of the body.  Sometimes it may be transmitted through sores in mouth or genitals too. Sores Open cuts  HIV can also be transmitted when infected objects come in direct contact with blood. Direct into blood © 2022, Aakash BYJU'S. All rights reserved HIV – Modes of Transmission There are the different ways with which a person can contact HIV disease.  Blood transfusion - Blood transfused from a person infected with HIV.  Pregnancy - The infected mother can transmit the virus through placenta to the baby, and even through mother’s milk after the birth of baby.  Non-sterile instruments - Needles or syringes used by an HIV patient will have some blood on it, which when reused by a non-infected person will result in transmission.  Unprotected sex - Sex without condom is way to come in contact with the vaginal fluid, semen or pre-seminal fluid. Non-sterile instruments © 2022, Aakash BYJU'S. All rights reserved Blood transfusion Unprotected sex Pregnancy HIV – Modes of Transmission How HIV is NOT transmitted? Sharing food Insect bite Touching Sharing pool © 2022, Aakash BYJU'S. All rights reserved HIV - Treatment & Diagnosis Treatment  Antiretroviral drugs - Partially effective, cannot prevent death but can prolong the life o Zidovudine or Azidothymidine (AZT) - First and still the drug of choice  Other drugs with similar action as AZT are all nucleoside analogs, similar to the naturally occurring nucleosides in RNA and DNA o Block conversion of retroviral RNA into DNA o Examples - Dideoxyinosine (DDI), dideoxycytidine (DDC), stavudine (D4T)  Zidovudine and Nevirapine are given to HIV positive pregnant women to ensure that their children do not carry the infection. Diagnosis  Enzyme Linked Immunosorbent Essay (ELISA) is the widely used test  Western blotting is used for confirmation of ELISA positive cases © 2022, Aakash BYJU'S. All rights reserved HIV – Prevention  The first step towards prevention of HIV infection is educating and creating awareness amongst people.  In India, NACO (National AIDS Control Organisation) is a governmental organisation that provides leadership to HIV/AIDS control programme.  It has approved “Teach AIDS” curriculum to be used in India.  It monitors blood bank licensing and blood donation activities.  It controls/monitors the testing and reporting of infection transmitted through blood transfusion. © 2022, Aakash BYJU'S. All rights reserved HIV – Prevention World Health Organisation  WHO has come up with several methods to prevent the transmission of HIV: o Free distribution of condoms o Ensures usage of disposable needles in hospitals o Conducting camps for regular check-ups in HIV prone population o Making blood safe from HIV © 2022, Aakash BYJU'S. All rights reserved Tumour Cell vs Normal Cell Normal cell Tumour cell Cell division is definite and regulated Cell division is indefinite and unregulated Contact inhibition present - Cell growth gets arrested when two or more cells come in contact Contact inhibition fails leading to unregulated growth. Growth factors bring about controlled cell differentiation Cell proliferation is uncontrolled Absence of normal angiogenesis amidst cells dividing normally Extensive angiogenesis (blood vessels formation) is seen in regions of tumour © 2022, Aakash BYJU'S. All rights reserved Tumour Types of tumours Benign tumor Malignant tumour  Grows quickly and spreads to other body parts  Localised at particular location  Does not spread to other body parts  Not as harmful as malignant tumour  Causes limited damage to body © 2022, Aakash BYJU'S. All rights reserved  Are mass of proliferating cells called neoplastic or tumour cells  Process by which cancer cells spread to other body parts is called metastasis  Cancer cells metastasise when they get into bloodstream or the lymph nodes and form secondary tumours across various sites in the body. Causes of Cancer Physical agents Ionising radiations (higher energy radiation) like X-rays and gamma rays and non-ionising radiations (lower energy radiations) like UV cause DNA damage leading to neoplastic transformation (abnormal growth of mass of tissue). © 2022, Aakash BYJU'S. All rights reserved Chemical agents Chemical carcinogens present in tobacco smoke have been identified as a major cause of lung cancer. Biological agents  Cellular or Proto-oncogene is a gene involved in cellular metabolism.  Mutations (changes) in a proto-oncogene may cause it to become an oncogene, which can cause the growth of cancer cells. Causes of Cancer Biological agents Oncogenic virus Viral oncogene Receptor Viral DNA Cancer causing virus is called oncogenic virus. These viruses bind to specific receptors present in the cells in our body. © 2022, Aakash BYJU'S. All rights reserved These viruses transfer their DNA to the host cell nucleus where the viral oncogene becomes part of the host DNA and hence the cell becomes neoplastic. Neoplastic cell Tumour Detection of Cancer  Diagnosis of cancer cannot be done just on the basis of symptoms as they may resemble symptoms of many other diseases.  Hence, we use other tools for confirmation. Cancer detection tools Biopsy Suspected tissue is extracted, sliced into thin pieces, stained and viewed under microscope © 2022, Aakash BYJU'S. All rights reserved Radiography X-ray ELISA CT scan MRI Uses X-ray to generate 3-D images of organs Uses magnetic field and nonionizing radiations Molecular biology Used to detect genes with inherited susceptibility for certain cancers Stages of Cancer  Benign tumour  Confined to the place where it started  Often curable Stage 0  Early-stage cancer  Contained within the organ  Not spread to lymph nodes and other parts of the body Stage 1 Outer layer Cancer lumps Muscle Sub mucosa Mucosa © 2022, Aakash BYJU'S. All rights reserved Stage 2 Stage 3  Later stages of cancer  Grow deep into the tissue  May have spread to lymph nodes but usually not other parts of the body Stages of Cancer  Advanced cancer  Grows deep into the tissue  Spreads to lymph nodes and other parts of the body (metastasis) Stage 0 Stage 1 Outer layer Cancer lumps Muscle Sub mucosa Mucosa © 2022, Aakash BYJU'S. All rights reserved Stage 2 Stage 3 Stage 4 Treatment of Cancer Common approaches for treatment of cancer Chemotherapy Surgery Radiation therapy Immunotherapy © 2022, Aakash BYJU'S. All rights reserved Treatment of Cancer Chemotherapy  Chemotherapeutic drugs are used to :○ ○ ○ kill cancer cells stop the spread slow their growth  The drugs are administered by :o mouth o in shots (injection using syringe)  Side effects of drugs are :o Hair loss o Anaemia o Tiredness, etc o Intravenously (in veins) Chemotherapeutic drugs Cancer cells Treatment of cancer with the use of drugs © 2022, Aakash BYJU'S. All rights reserved Treatment of Cancer Surgery Immunotherapy  Localised cancerous masses are removed through surgical procedure.  Immune system is not able to detect and destroy the tumour cells.  This process is highly effective for benign tumours as they are localised.  So, the patients are administered with biological response modifiers (glycoproteins) such as αinterferons which activate their immune system and help in destroying the tumour. Radiation therapy  The affected body part is exposed to radiations like X-rays, protons or other types of energy to kill the cancer cells. © 2022, Aakash BYJU'S. All rights reserved Types of Cancer Based on the Site of Origin Carcinomas Sarcomas These are cancerous tumours of epithelial tissues. These are cancerous tumours of connective tissues such as blood vessels, muscles, bones, etc. © 2022, Aakash BYJU'S. All rights reserved Leukemias Lymphoma These are cancer of the blood cells. These are cancer of the lymphatic systems such as spleen, lymph nodes, thymus glands, etc. Classes of Drugs Habitual administration of drugs either obtained from illegal or legal sources that are administered for creating pleasurable effects and harms one's health is called drug abuse. Generally, the abusive drugs belong to following classes. 1 2 3 Opioids Cannabinoids Coca alkaloids Most of these are obtained from flowering plants and some from fungi. Morphine belongs to the class of drugs called opioids. © 2022, Aakash BYJU'S. All rights reserved Opioids  Opioids are extracted from latex (whitish milk) of poppy plant Papaver somniferum.  Opioids and its derivatives act on the central nervous system and gastrointestinal tract in humans.  Opioids attach to proteins called opioid receptors on nerve cells in the brain, spinal cord, gut, and other parts of the body.  Opioid derivative, morphine undergoes acetylation to produce another derivative heroin.  Opioids are administered by either injecting or snorting. © 2022, Aakash BYJU'S. All rights reserved Structure of morphine Opioids Effects  After opioid administration, the common effects seen by people are: o Physiological o Psychological Vomiting Constipation Slowdown in body function Euphoria o Physical © 2022, Aakash BYJU'S. All rights reserved Cannabinoids  Cannabinoids are class of drugs obtained from the inflorescence of plant Cannabis sativa. Types of cannabis Marijuana - leaves Hashish - cannabis extract Charas (Resin) - whole plant © 2022, Aakash BYJU'S. All rights reserved Structure of cannabinoid molecule  Cannabinoids (Ganja/Charas/Hashish) are administered by inhalation or oral ingestion. Coca Alkaloids/Cocaine  Coca alkaloids are also called as cocaine.  They are obtained from Erythroxylum coca, native to South America.  They are commonly called as coke or crack.  They are administered by snorting. © 2022, Aakash BYJU'S. All rights reserved Euphoria Paranoia Hallucinations Increased body temperatures Energetic Increased heart beat Did you know  Hallucinations are caused by other plants as well such as: Atropa belladonna  Datura Morning glory Fly agaric Several such plants have been used for hundreds of years in: o Rituals and religious ceremonies o Folk medicines © 2022, Aakash BYJU'S. All rights reserved Drugs with History of Abuse  At low dose:  Relieve tension and anxiety  Induce sleep At prescribed doses, aids in treating:  Anxiety  Alcohol withdrawal  Insomnia  Anaesthetic  Seizure control © 2022, Aakash BYJU'S. All rights reserved Barbiturates (Class of sedative hypnotics) Benzodiazepines (Class of tranquilisers) Slight overdose can cause death or coma Overdose along with alcohol can be lethal Drugs with History of Abuse  Treats attention deficit hyperactivity disorder (ADHD) Amphetamines  Narcolepsy Overdose causes physical and physiological disorders  Were used as antidepressants  Hallucinogen  Treat mental illness (anxiety, psychosomatic diseases)  Used as antidepressants © 2022, Aakash BYJU'S. All rights reserved  Overdose leads to psychosis Lysergic acid diethylamide (LSD)  Lacks accepted safety under medical supervision Addiction It is the habitual, physiological and psychological dependence on a substance (tobacco, alcohol, drugs) which is beyond control of the body. Addiction Tobacco © 2022, Aakash BYJU'S. All rights reserved Drugs Alcohol Tobacco Addiction Tobacco  It is obtained from the leaves of plant Nicotiana tabacum.  It is being consumed for about 400 years.  Tobacco contains a poisonous alkaloid called nictoine that is a major component of tobacco, cigarettes and is responsible for addiction to these. Modes of tobacco use Smoking  Inhaling tobacco smoke from cigars, cigarettes, bidis, pipes and hookah. © 2022, Aakash BYJU'S. All rights reserved Chewing  Tobacco in powdered form can be chewed with paan.  It is also placed between the lip and the gum for a period of time then spat out. Snuffing  When powdered tobacco is taken through nose, it is called snuffing. Effects of Tobacco Increased blood pressure Increased risk of heart disease Increased heart rate Sterility in men © 2022, Aakash BYJU'S. All rights reserved Stimulates adrenal gland to release adrenaline and noradrenali ne Withdrawal Syndrome Carbon monoxide  Carboxyhaemoglobin compound does not readily dissociate unlike oxyhaemoglobin (formed when oxygen combines with haemoglobin) or carbaminohaemoglobin (formed when carbon dioxide combines with haemoglobin).  Thus, haemoglobin molecules are not available for the transport of oxygen, and this leads to oxygen deficiency in the tissues. In alveoli Hb Free haemoglobin © 2022, Aakash BYJU'S. All rights reserved + O2 HbO2 In tissues Oxygen Oxyhaemoglobin Diseases Caused by Smoking Tobacco Cancer Heart diseases Diseases caused by smoking tobacco Bronchitis Emphysema Gastric ulcers © 2022, Aakash BYJU'S. All rights reserved Adolescence  Adolescents are individuals within the average age group of 12-18 years who are transitioning from childhood to adulthood.  Apart from major physical changes due to attainment of sexual maturity, adolescents also undergo cognitive, social and emotional changes as they gradually mature into adults. © 2022, Aakash BYJU'S. All rights reserved Adolescence Curiosity to try new things Academic stress Why are adolescents more likely to get addicted Perception that it’s the fashion © 2022, Aakash BYJU'S. All rights reserved Unsupportive family structures Common Effects of Drugs and Alcohol Abuse Continuous use of these leads to over dependence on them. Aggressive behaviour Drop in academic performance Common effects Lack of interest in personal hygiene © 2022, Aakash BYJU'S. All rights reserved Stealing to buy these products Diseases Caused by Alcohol  Decreases sleep Effects on brain Increased urine output (Diuresis)  Person loses judgement  Coordination of muscles is lost  Slurring of speech  Loss of consciousness Liver disorders like cirrhosis © 2022, Aakash BYJU'S. All rights reserved Misuse of drugs Drugs are not harmful, however when taken for a purpose other than medicinal use or in amounts/frequency that impairs one’s physical, physiological or psychological functions, it constitutes drug abuse, which is harmful. Doping  Drugs are misused by certain sportspersons.  They misuse narcotics, steroids, diuretics and hormones to improve their performance.  This is called doping. © 2022, Aakash BYJU'S. All rights reserved Side Effects of Doping In females Masculinisaton Excessive hair growth Increased aggressiveness Enlargement of the clitoris Mood swings Abnormal menstrual cycle Depression Deepening of voice © 2022, Aakash BYJU'S. All rights reserved Side Effects of Doping In males Acne Decreased sperm production Increased aggressiveness Potential for liver dysfunction Mood swings Gynaecomastia(breast enlargement) Depression Premature baldness Reduction of size of the testicles Prostate enlargement © 2022, Aakash BYJU'S. All rights reserved Withdrawal Syndrome The body tends to experience withdrawal if the consumption of drugs/alcohol is suddenly stopped which makes it even more difficult for the person to stop using these. Anxiety Shaking Symptoms Nausea © 2022, Aakash BYJU'S. All rights reserved Sweating Withdrawal Syndrome  It is difficult to overcome withdrawal syndrome and go completely clean.  Thus, prevention is better.  Preventing kids from diverting to alcohol or drugs should be a high priority. How to avoid getting diverted to drugs? Avoid undue peer pressure Every child is unique in their own terms. Encouraging children for better academic performance is good; however comparing them to their peers, scolding them for not scoring well, should be avoided by the parents and teachers. © 2022, Aakash BYJU'S. All rights reserved Withdrawal Syndrome How to avoid getting diverted to drugs? Education and counselling Counselling the child regarding stresses in their life and how to overcome them is important. Seeking help from parents and peers The child should be comfortable enough to share his/her problems with his/her parents and friends and find appropriate solutions to the problem. Seeking professional guidance in case of psychological disorders © 2022, Aakash BYJU'S. All rights reserved Summary Types of immunity Innate 1st line of defence Physical barriers Acquired 1st categorisation Humoral Cell mediated Physiological barriers 2nd categorisation 2nd line of defence Cellular barriers Cytokine barriers © 2022, Aakash BYJU'S. All rights reserved Active Passive Summary Types of Adaptive immunity Active Natural  Infectious agents gaining access into body activates natural immunity © 2022, Aakash BYJU'S. All rights reserved Passive Artificial  Resistance induced by injecting vaccine is artificial immunity Natural  Receiving readymade antibodies naturally from mother  E.g. - IgG through placenta and IgA through colostrum Artificial  Artificial administration of readymade antibodies  E.g. - Anti-venom injections Summary Lymphoid organs Based on the role in the development of the immune cells Primary lymphoid organs Thymus Bone marrow Secondary lymphoid organs Spleen Tonsils Peyer’s patches © 2022, Aakash BYJU'S. All rights reserved Lymph nodes Appendix Summary Humoral immunity Pathogens (antigen) enter the cell B-lymphocytes get activated Some B-cells differentiate into plasma cells to secrete antibodies against pathogen © 2022, Aakash BYJU'S. All rights reserved Undifferentiated B-cells become memory cells to protect against future attacks Cell-mediated immunity Bone marrow produces immature lymphocytes Travel to thymus and differentiate into Tlymphocytes T-lymphocytes migrate to lymphoid tissue and differentiate into one of the four: Helper T-cell Cytotoxic/ Killer T-cell Suppressor T-cell Memory T-cell Summary Vaccination is the administration of vaccine to stimulate the immune system against the pathogen, thereby developing protection from a disease. Types of vaccines Antigen only © 2022, Aakash BYJU'S. All rights reserved Killed/Weakened pathogen RNA Summary Dust Pollens The exaggerated response of the immune system to certain antigens present in the environment is called allergy. Substances which trigger such exaggerated response Animal dander Allergens Certain medicines © 2022, Aakash BYJU'S. All rights reserved Food items Mites Summary Bacterial diseases Typhoid Pneumonia Salmonella typhi Streptococcus pneumoniae Viral diseases Common cold Rhinovirus © 2022, Aakash BYJU'S. All rights reserved Acquired Immunodeficiency Syndrome Human Immunodeficiency Virus Summary Helminthic diseases Fungal diseases Protozoan diseases Filariasis Ringworms Malaria Wuchereria bancrofti and Wuchereria malayi Microsporum, Trichophyton, Epidermophyton Plasmodium Ascariasis Amoebiasis Ascaris lumbricoides Entamoeba histolytica © 2022, Aakash BYJU'S. All rights reserved Summary Viral diseases Polio Rabies Dengue fever Poliovirus Lyssavirus, Rhabdovirus Flavi-ribovirus Flu Smallpox Influenza virus Variola virus Chickenpox Chikungunya Rubella Varicella zoster Chikungunya virus Rubella virus Mumps Measles Hepatitis Paramyxovirus Rubeola virus Hepatitis virus © 2022, Aakash BYJU'S. All rights reserved