Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Lesson 5.1 Immunity By Carone Fitness Immunity Immunity To protect you from being sick all the time, your body is constantly defending itself against infectious agents. Immunity is the body’s natural defenses against infection. 1 Immunity Immunity There are two types of immunity: Non-specific immunity Specific immunity Immunity Non-specific Immunity Non-specific immunity is the body’s natural defense that protects against infectious agents in a universal way. Non-specific immunity has four forms: Physical barriers Chemical barriers Body cells Inflammatory response 2 Immunity Physical Barriers The first line of defense against infection is provided by physical barriers. The main barrier is your skin. Unbroken skin keeps pathogens from entering your body’s tissues. Immunity Physical Barriers Mucus membranes are the soft, skin-like linings of your nose, mouth, and lungs that produce mucus. This mucus traps pathogens and keeps them from entering your body. Some mucus membranes are lined with cilia. Cilia are tiny hairs that catch pathogens before they enter the body. The pathogens are then expelled when you sneeze or cough. 3 Immunity Chemical Barriers The enzymes in tears and saliva are chemical barriers that help destroy bacteria. Pathogens in food can be eliminated by the gastric juices in your stomach, which are very acidic. These gastric juices also serve as a chemical barrier. Immunity Body Cells Once pathogens reach your bloodstream, your body alerts certain cells of the invasion. These cells are known as phagocytes. Phagocytes are white blood cells that group together to destroy foreign organisms. The process of phagocytes engulfing and terminating pathogens is known as phagocytosis. 4 Immunity Inflammatory Response When your body is invaded by pathogens, it triggers the inflammatory response. The inflammatory response is the body’s response to foreign pathogens characterized by an increased blood flow to facilitate the movement of phagocytes into body tissues. Symptoms of inflammation include: Heat Redness Swelling Immunity Specific Immunity Specific immunity is the body’s way of fighting off pathogens that have evaded its non-specific immunity. During specific immunity lymphocytes fight against the pathogens. Lymphocytes are a kind of white blood cell that can be found in blood vessels and lymph vessels. There are two main types of lymphocytes: B Cells and T Cells. 5 Immunity Specific Immunity When B cells encounter a pathogen, they begin to grow and multiple. The B cells then develop into plasma cells. The plasma cells release antibodies to destroy the pathogen. Antibodies are proteins that destroy or neutralize pathogens. The antibodies then remain in the blood to become active if that same pathogen enters the body again. Immunity Specific Immunity There are two categories of T cells: killer and helper cells. Killer T cells are triggered to multiply by the presence of abnormal body cells. They attach themselves to the foreign cells and release toxins to destroy them. Helper T cells aid B cells and control other aspects of the immune system. 6 Immunity Prevention In order to provide protection from pathogens, your body develops a natural resistance to those pathogens. This is known as immunity. Research and modern technology have led to the creation of vaccinations. Vaccinations provide antibodies that are needed to fight off a certain pathogen, should you ever be exposed to it. Immunity Prevention Other guidelines you can follow to help prevent infectious diseases include the following: Make sure to get good nutrition, regular exercise, and adequate sleep. Shower frequently in order to keep your hair, skin, and nails clean. 7 Immunity Prevention Avoid sharing eating or drinking utensils with other people. Wash your hands frequently. Store and prepare food properly. Presented By Carone Fitness 8