Immune system
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Immune system and its mechanism of response again microbial infection. Importance of Immune cells.
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Immune system
- 2. Contents Immune system Microbial Infection Defense against Microbes Immune system response
- 3. Introduction Immune system is made up of Special organs, cells and chemicals that fight infection(microbes)
- 4. Immune system Immune system – records microbial entry Main parts are WBC Antibodies Lymphatic system Thymus, Bone marrow, Spleen
- 5. Immune system – Main Characters White Blood Cells Bone marrow Soldiers of the body Constant Patrol Antibodies Microbes/Toxins Antigens Mark microbes / toxin as foreign.
- 6. Immune system – Main characters Lymphatic system Network of delicate tubes Manage fluid level Lymph nodes & lymph vessels Lymphocytes Thymes Bone marrow Spleen
- 7. Immune system and Microbial Infection First Line of Defense First Line of Defense Second Line of Defense Third Line of Defense 01 03 02
- 8. About the Disease Mars is a cold place. The planet is full of iron oxide dust Mars Is a gas giant and the biggest planet in the Solar Jupiter It’s a gas giant, composed mostly of hydrogen and helium Saturn
- 13. About the Disease Mars is a cold place. The planet is full of iron oxide dust Mars Is a gas giant and the biggest planet in the Solar Jupiter It’s a gas giant, composed mostly of hydrogen and helium Saturn
- 25. Immune system How does our Immune system works? 01
- 26. Games Play now
- 27. Identify Immune organs Macrophage Click on the cell which perform Phagocytosis Basophil
- 28. Macrophage Macrophages are specialized cells involved in the detection, phagocytosis and destruction of bacteria Next
- 30. Dendritic cells Click on the Non APC Neutrophil
- 31. Dendritic cells It is one of an Antigen presenting cell Back
- 32. Neutrophil Not an Antigen Presenting cell Next
- 33. Skin Which of the following is first line of immune system? Macrophage
- 34. Skin Next
- 35. Macrophage Back
Hinweis der Redaktion
- Every day we’re exposed to millions of microscopic germs – bacteria, viruses, fungi, parasites. Our immune system protects us from them so that we don’t get sick. But sometimes a germ (or pathogen) is able to get into our system – through a cut, from breathing in droplets from someone’s cough, or if our immune system has become weakened. When this happens, our body launches an attack Our immune system is essential for our survival. Without an immune system, our bodies would be open to attack from bacteria, viruses, parasites, and more. It is our immune system that keeps us healthy as we drift through a sea of pathogens. Crucially, it can distinguish our tissue from foreign tissue — self from non-self. Dead and faulty cells are also recognized and cleared away by the immune system.
- The immune system keeps a record of every microbe it has ever defeated, in types of white blood cells (B- and T-lymphocytes) known as memory cells. This means it can recognize and destroy the microbe quickly if it enters the body again, before it can multiply and make you feel sick. Some infections, like the flu and the common cold, have to be fought many times because so many different viruses or strains of the same type of virus can cause these illnesses. Catching a cold or flu from one virus does not give you immunity against the others. If the immune system encounters a pathogen, for instance, a bacterium, virus, or parasite, it mounts a so-called immune response. Later, we will explain how this works, but first, we will introduce some of the main characters in the immune system.
- White blood cells are the key players in your immune system. They are made in your bone marrow and are part of the lymphatic system. White blood cells move through blood and tissue throughout your body, looking for foreign invaders (microbes) such as bacteria, viruses, parasites and fungi. When they find them, they launch an immune attack. White blood cells include lymphocytes (such as B-cells, T-cells and natural killer cells), and many other types of immune cells. A white blood cell (yellow), attacking anthrax bacteria (orange). Antibodies Antibodies help the body to fight microbes or the toxins (poisons) they produce. They do this by recognizing substances called antigens on the surface of the microbe, or in the chemicals they produce, which mark the microbe or toxin as being foreign. The antibodies then mark these antigens for destruction. There are many cells, proteins and chemicals involved in this attack.
- The lymphatic system is a network of delicate tubes throughout the body. The main roles of the lymphatic system are to: manage the fluid levels in the body react to bacteria deal with cell products that otherwise would result in disease or disorders absorb some of the fats in our diet from the intestine. The lymphatic system is made up of: lymph nodes (also called lymph glands) -- which trap microbes lymph vessels -- tubes that carry lymph, the colourless fluid that bathes your body's tissues and contains infection-fighting white blood cells lymphocytes). Lymphocytes help the body to remember previous invaders and recognize them if they come back to attack again. The spleen is a blood-filtering organ that removes microbes and destroys old or damaged red blood cells. It sits in the upper left of the abdomen. Thymus — a gland between the lungs and just below the neck. The thymus produces the white blood cells called T-lymphocytes. Bone marrow — found in the center of the bones, it also produces red blood cells. Bone marrow is the spongy tissue found inside your bones. It produces the red blood cells our bodies need to carry oxygen, the white blood cells we use to fight infection, and the platelets we need to help our blood clot. Lymphocytes begin their life in bone marrow. Some stay in the marrow and develop into B lymphocytes (B cells),
- Our immune system protects us from them so that we don’t get sick. But sometimes a germ (or pathogen) is able to get into our system – through a cut, from breathing in droplets from someone’s cough, or if our immune system has become weakened. When this happens, our body launches an attack.
- It starts with the white blood cells (or leukocytes). They’re our germ fighting cells. They patrol the body looking for foreign bodies like viruses.
- Every day we’re exposed to millions of microscopic germs – bacteria, viruses, fungi, parasites.
- But sometimes a germ (or pathogen) is able to get into our system – through a cut, from breathing in droplets from someone’s cough, or if our immune system has become weakened.
- The innate response begins immediately and can identify and destroy invaders quickly. This innate immunity includes the external barriers of our body The first line of defense against pathogens — such as the skin and mucous membranes of the throat and gut. This response is more general and non-specific. If the pathogen manages to dodge the innate immune system, adaptive or acquired immunity kicks in.
- skin - a waterproof barrier that secretes oil with bacteria-killing properties other defenses - body fluids like skin oil, saliva and tears contain anti-bacterial enzymes that help reduce the risk of infection. The constant flushing of the urinary tract and the bowel also helps.
- lungs - mucous in the lungs (phlegm) traps foreign particles, and small hairs (cilia) wave the mucous upwards so it can be coughed out digestive tract - the mucous lining contains antibodies, and the acid in the stomach can kill most microbes two innate immune responses are triggered, phagocytosis and inflammatory responses.
- They all play important roles in the immune system. These cells surround and absorb pathogens and break them down, effectively eating them. There are several types, including: Mast cells — they have many jobs, including helping to heal wounds and defend against pathogens.
- Neutrophils — these are the most common type of phagocyte and tend to attack bacteria. Monocytes — these are the largest type and have several roles.
- Macrophages — these patrol for pathogens and also remove dead and dying cells. Phagocytes are hungry little buggers that eat pathogens for breakfast. They do this by surrounding the cell and absorbing it. When they do this they receive information from the proteins on the surface of the pathogen. These proteins are called antigens (or antibody generators). Phagocytes then send this info to the lymphocytes.
- The complement system is another vital component of the immune system. It works with the innate and adaptive responses. It is a cascade of proteins that alter or fragment later proteins, in specific sequences. The cascade triggers many actions including recruiting inflammatory cells, attracting phagocytes to the area and marking pathogens for phagocytosis, damaging the plasma membrane of a pathogen leading to its death and removing neutralized antigen-antibody complexes from the body.
- The signaling molecules that are used by cells of the immune system to communicate with each other are known as cytokines
- An antigen is a bacterium, fungus, virus, toxin, or foreign body. But it can also be one of our own cells that is faulty or dead. Initially, a range of cell types works together to recognize the antigen as an invader.
- Helper T cells (Th cells) — they coordinate the immune response. Some communicate with other cells, and some stimulate B cells to produce more antibodies. Others attract more T cells or cell-eating phagocytes. Killer T cells (cytotoxic T lymphocytes) — as the name suggests, these T cells attack other cells. They are particularly useful for fighting viruses. They work by recognizing small parts of the virus on the outside of infected cells and destroy the infected cells.