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The immune System. Ch 37. Benchmark SC.912.L.14.52. Explain the basic functions of the human immune system, including specific and nonspecific immune response, vaccines, and antibiotics. Ch 37, 32. VOCABULARY. pathogen, infectious disease, reservoir, endemic, epidemic, pandemic,
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The immune System Ch 37
Benchmark SC.912.L.14.52 • Explain the basic functions of the human immune system, including specific and nonspecific immune response, vaccines, and antibiotics. • Ch 37, 32
VOCABULARY • pathogen, • infectious disease, • reservoir, • endemic, • epidemic, • pandemic, • antibiotic, • lymphocytes, • antibodies, • immunization
pathogen • Things that cause infectious diseases such as bacteria, viruses protozoan, fungi and parasites
infectious disease, • A disease caused by a pathogen passed from one organism to another disrupting homeostasis
reservoir, • The source of the pathogen in the environment • Animals, people inanimate objects soil
endemic, • When a disease is found continually in small amounts within a population
epidemic, • Outbreaks of a disease that afflict many people
pandemic, • Widespread epidemics covering large areas of a continent or the entire world
antibiotic, • Drugs that kill or inhibit the growth of bacterial pathogens
lymphocytes, • A type of white blood cell made in the bone marrow
antibodies, • Proteins made by B lymphocytes that specifically react with foreign antigens
immunization • Deliberate exposure to an antigen so a primary response immunity and memory cells will develop
1. What are some examples of pathogens that cause infectious diseases? • Bacteria, fungi, protozoan, viruses
bacterial • Strep and staph
Protozoan • Malaria • Trypanosoma
Fungal • Ringworm • Tinea/ athletes foot
2. What is the germ theory? That microorganisms cause disease!
3. Robert Koch’s experiment with anthrax led to a set of steps known as Koch’s postulates. Summarize the steps and describe their purpose • 1. isolate the suspected pathogen • 2. grow the isolated pathogen • 3. place the isolated pathogen in a healthy host to see if it causes the disease • 4. re isolate the pathogen from the newly infected host.
4. Give some examples of reservoirs of pathogens • People , soil, animals, objects
5. Differentiate between the three main methods of pathogen transmission. • 1.direct • 2. indirect • 3. vectors
6. Based on the above methods of transmission, what are some precautions we can take to prevent infection? • Hand washing, keeping hands out of mouths and eyes, sanitation of water and food, surface of objects sanitized, control of insects and other arthropods quarantine of individuals who are known to have a disease
7. How has the widespread use of antibiotics caused many bacteria to become resistant to antibiotics? • Natural selection! The overuse leads to the ones who are naturally resistant surviving and reproducing producing strains of bacteria that are resistant to the antibiotics.
Antibiotics • Used only for bacterial diseases! They interfere with protein synthesis or cell wall formation for prokaryotes. • Take them all to prevent resistant strains forming! • Do not take them if you have a virus! They will not help!!! • Ex. Penicillin, erythromycin and neomycin
Antibiotics • Antibiotics are powerful medicines that fight bacterial infections. They do NOT work on viral or fungal infections!!! • How do Antibiotics work? • Inhibition of Cell Wall Synthesis (most common mechanism) ex. Vancomycin, Bacitracin • Inhibition of Protein Synthesis (Translation) (second largest class) ex.Tetracyclines Macrolides, Clindamycin • Alteration of Cell Membranes ex.Bacitracin (topical) • Inhibition of Nucleic Acid Synthesis ex. Metronidazole, Bacitracin (topical) • Antimetabolite Activity ex. Sulfonamides & Dapsone
8. Why are antibiotics not effective against viruses? • Antibiotics attack the cell wall of prokaryotes, viruses do NOT have a cell wall!
9. What is nonspecific immunity? • General defenses against any pathogen, not a specific one! • First line of defense • Usually trying to prevent disease
10. What are some of the body’s barriers against infection? • Skin, chemical barriers, mucus, saliva, cilia, tears
More Non specific immunity • It also includes internal responses that are not specific to the invader such as white blood cells that engulf microorganisms by phagocytosis (neutrophils and macrophages) • Complement: proteins that help the cell destroy invaders. • Interferon: Proteins that prevent viral replication • Inflammatory response: Increased blood flow, increased white blood cells, raised temperature all create a hostile environment for the invaders! Pain, heat and redness from infection are a sign of inflammation!
The inflammatory response • http://www.bing.com/images/search?q=inflammatory+response&view=detail&id=DC4BDA458BA89604DB0E1FEE687CCA549699627A&first=0&FORM=IDFRIR
Complement system (non) • If germs get through the body's physical and chemical barriers ( the Non specific immunity) into the bloodstream, a mixture of liquid proteins called complement is activated and attacks them. The complement system includes a series of proteins. • While there are millions of different antibodies in your blood stream, each sensitive to a specific antigen, there are only a handful of proteins in the complement system. They float freely in your blood. • Complements are manufactured in the liver. The complement proteins are activated by and work with (complement) the antibodies. • They cause lysing (bursting) of cells and signal to phagocytes that a cell needs to be removed.
Interferon ( non) • Interferon is another type of protein produced by most cells in the body. The job of interferon is to let cells signal one another. When a cell detects interferon from other cells, it produces proteins that help prevent viral replication in the cell and also stimulates killer cells.
Hormone (non) • There are several hormones generated by the immune system. These hormones are generally known as lymphokines. • Some hormones in the body suppress the immune system. These are the steroids and corticosteroids (components of adrenaline. This is why taking some steroids can make you more susceptible to getting an infection!
11. Describe the following non-specific responses: • a. Cellular defense: phagocytosis of pathogens by macrophages. Complement proteins that help the phagocytosis process • b. Interferon: a chemical released by cells infected by a virus. It stimulates the cells to release anti viral proteins to keep the virus from replicating. • c. Inflammatory Response: increased blood flow: redness and heat. Increased permeability of vessels: pus, wbc’ to kill pathogens
Specific Immunity • If things get past the non specific line of defense… • The Lymphatic System has items designed to attack specific invaders! • B-Cells produce antibodies made in response to specific antigens ( invaders) • T-cells: Also are specific to antigens produce cytotoxic T cells that destroy pathogens.
Lymphatic system • Lymph nodes are basically filters that trap germs and other foreign bodies. • The nodes have armies of lymphocytes to deal with the germs. Lymphocytes are a type of white blood cell, which neutralizes or destroys germs. • The lymph nodes can become swollen when fighting an infection. • That’s why the doctor feels your arm pits and groin area during an exam!
Lymphoid organs include the bone marrow and the thymus, as well as lymph nodes, spleen, tonsils and adenoids, the appendix, and clumps of lymphoid tissue in the small intestine known as Peyer's patches. • There are about 2 to 4 pints of lymph fluid in the average body.
Spleen • The spleen filters the blood looking for foreign cells and removes old red blood cells. It is an organ about the size of a fist in the upper left of the abdomen. • It contains two main types of tissue: red tissue that disposes of the worn-out blood cells, and white tissue that contains lymphoid tissue. • Different part of the spleen specialize in different kinds of immune cells. When microorganisms get carried by the blood into the red tissue, they become trapped by the immune cells known as macrophages.
Thymus • The thymus is located in your chest, between your breast bone and your heart. It is responsible for producing T-cells and is important for T cell maturation.
13. What is the function of the lymphatic system? • Filters blood, destroys foreign microorganisms, absorbs fat, returns excess fluids to the circulatory system
14. What are some of the organs of the lymphatic system? • Lymph tissue, fluid, nodes, vessels, tonsils, spleen and thymus
Antibodies (specific) • Antibodies (also referred to as immunoglobulins and gammaglobulins) are are Y-shaped proteins that respond to specific bacteria, viruses or toxins, called antigens. They are produced by white blood cells. • Antibodies can bind to toxins, disabling their chemical actions or signal that an invader needs to be removed. • These antibodies are divided into five classes. Their names are generally abbreviated. For instance, Immunoglobulin A is abbreviated IgA. • Here are all of the abbreviations: IgA, IgD, IgE, IgG, i IgM. http://www.bing.com/images/search?q=the+immune+system&view=detail&id=A1D334A117B30F6C7CD900279DD504F592134A58&first=91&FORM=IDFRIR
White blood cells/Leukocytes • White blood cells are a very important part of your immune system. They are actually a large collection of different cells that work together to destroy bacteria and viruses. They act like independent, living single-cell organisms that can move like amoeba and capture things on their own by engulfing them. Most of them are created in the bone marrow and start out as stem cells. • Leukocytes • Lymphocyte • Monocytes • Granulocytes • B-cells • Plasma cells • T-cells • Helper T-cells • Killer T-cells • Suppressor T-cells • Natural killer cells • Neutrophils • Eosinophils • Basophils • Phagocytes • Macrophages
There are three types of Leukocytes: • Granulocyteswhich comprise 50 to 60 percent of all leukocytes. They are further divided into three types of Granulocytes: Neutrophils, Eosinophils and Basophils. Granulocytes get their name because they contain granules. These granules contain different chemicals depending on the type of cell.
Monocytes (non) • which comprise approximately 7 percent of all leukocytes. Monocytes eventually become macrophages.
Lymphocytes ( specific)comprise 30 to 40 percent of all leukocytes. • Lymphocytes travel through the blood searching for foreign cells. • There are two kinds – • B lymphocytes (B cells) that mature in bone marrow and use antibodies to target bacteria. • T lymphocytes (T cells) that mature in the thymus and actually do the fighting.