Diseases and Immunity PDF

Diseas e and Immun  https://www.youtube.com/watch?v=JnlULOjUhSQ A pathogen is a disease-causing organism Pathogens are passed on from one host to another and therefore the diseases they cause are known as transmissible Diseases Pathogens can be passed on from host to host in different ways,...

Diseas e and Immun  https://www.youtube.com/watch?v=JnlULOjUhSQ A pathogen is a disease-causing organism Pathogens are passed on from one host to another and therefore the diseases they cause are known as transmissible Diseases Pathogens can be passed on from host to host in different ways, including: (a) by direct contact, including through blood and other body fluids (b) indirectly, including from contaminated surfaces, food, animals and air  Body defense ange the flash cards to form a classification System chart of our defense System Phagocytes engulfing and Chemical barriers digesting Nose hairs Chemical barriers are pathogenic cells make it difficult for pathogens to get past chemical substances in the them further up the nose so they are not body which help to trap or inhaled into the lungs destroy pathogens Stomach acid Cellular barriers the acidity kills pathogens Mucus are the protection offered by the cells of our that enter our digestive Traps bacteria that immune system(WBCs), which take part in system via the food we eat. enters the respiratory combating against pathogens and disease system via air Skin Mechanical barriers Lymphocytes overs almost all parts of your body to Mechanical barriers act as a producing antibod prevent infection from pathogens. If it is physical obstruction in ies cut or grazed, it immediately begins to order to prevent pathogens heal itself, often by forming a scab. from entering our body.  Nose hairs make it difficult for pathogens to get past Mechanical barriers them further up the nose so they are not Mechanical barriers act as a inhaled into the lungs physical obstruction in Skin order to prevent pathogens overs almost all parts of your body to prevent from entering our body. infection from pathogens. If it is cut or grazed, it immediately begins to heal itself, often by forming a scab. Body Mucus Chemical barriers Traps bacteria that enters the defens Chemical barriers are respiratory system via air e chemical substances in the Stomach acid body which help to trap or the acidity kills pathogens that destroy pathogens enter our digestive system via the System food we eat. Cellular barriers Lymphocytes are the protection offered by the cells producing antibodies of our immune system(WBCs), which Phagocytes take part in combating against engulfing and digesting pathogens and disease pathogenic cells  Phagocytosis Phagocytosis is the mechanism by which phagocytes digest pathogens. Phagocyte extends itself and engulfs the pathogen Enzymes digest the pathogen.  Antigens & Antibodies All cells have proteins and other substances projecting from their cell membrane These are known as antigens and are specific to that type of cell Lymphocytes have the ability to ‘read’ the antigens on the surfaces of cells and recognise any that are foreign They then make antibodies which are a complementary shape to the antigens on the surface of the pathogenic cell. The antibodies attach to the antigen and cause agglutination (clumping together) This means the pathogenic cells cannot move very easily At the same time, chemicals are released that signal to phagocytes that there are cells present that need Watch tothe be video for more understanding….. destroyed https://www.youtube.com/watch?v=qWSWWPZYGH U  Active Immunity Passive Immunity lymphocytes produce memory cells, which are long- Passive immunity is a short-term defense again lived cells that remain in the blood even after the a pathogen by antibodies transferred from one infection is over. They have the ability to rapidly individual to another (rather than making their produce the original antibodies if it were to come own). across the same pathogen/antigen again. Making antibodies and developing memory cells for This is when ready-made antibodies, from future response to infection is known as active another source, are introduced to the immunity body There are two ways in which this active immune Passive immunity is a fast-acting, short- response happens: term defence against a pathogen by 1. The body has become infected with a antibodies acquired from another pathogen and so the individual, eg: lymphocytes go through the process of making From mother to infant via breast milk - antibodies this is important as it helps the very specific to that pathogen. young to fight off infections until they are older and stronger and their immune 2. Vaccination system is more responsive Injecting antibodies for certain diseases where the individual is already infected Active immunity is slow acting and provides long- and a fast response is required, lasting immunity like rabies or tetanus Vaccination Autoimmune disease Some diseases are caused by the immune system targeting and destroying friendly body cells. Type 1 diabetes is an example of an autoimmune disease whereby immune cells attack insulin producing beta cells in the pancreas.  Controlling Spread of Measure Disease Hygienic food Keep food at low temperatures so microbes cannot grow/reproduce slowly. preparation Wash hands and utensils properly before cooking food Cooks food well long enough to kill bacteria. Keep the food covered. Wash hand well before handling food. Good personal Wash your hands with soap that removes pathogens. hygiene Use tissues while coughing and sneezing. Wash hands after using washroom. Waste disposal Dispose waste food in a sealed container to prevent growth of vectors. Keep dustbins covered. Waste should be discarded away from human habitation. sewage treatment Homes and public places to have proper plumbing systems and drains to safely remove faeces and waste that could be breeding place for pathogens. Treatment of sewage to remove solid waste and remove pathogens before being released into the environment. clean water supply Water used for drinking and cooking should be treated with chemicals/ozone/ultraviolet rays to kill microbes.