Presentation on theme: "Chapter 40 “The Immune System”"— Presentation transcript:
1 Chapter 40 “The Immune System” 40.1 “Disease”Objective:Define the term “disease”Describe “Germ Theory” & “Koch’s Postulates”Discuss disease Transmission & Prevention.
2 Introduction (Do not write) How would you define an infection?Sickness, contamination of some sort.By what?Bacteria, or some “other” disease causing organism.How does the human body become infected?Cuts, breathing, eating
3 DiseaseA disease is any change, other than injury, that disrupts “normal” body functions.Some are inherited (hemophilia), some are caused by environment, others by bacteria, viruses, or fungi.
4 Pathogens Infect the body Cause disease Virus Bacteria Malaria Parasite
5 The Germ TheoryObservations made by Louis Pasteur & Robert Koch concluded that diseases were caused by “germs”, rather than “evil spirits”.Koch developed guidelines to identify microorganisms that caused diseases
6 Agents of Disease Ideal conditions for pathogen growth - your body! Most are harmlessBacteria release toxins which make you sickViruses (non-living) invade cells and eventually cause them to pop
8 Fighting Pathogens Prevention Drugs Antibiotic – attacks cell wall of bacteriaDo not work against viruses – no cell wall
9 40.2 “The Body’s Defense System” Objective:Identify Non-Specific & Specific Defenses.Define/describe the term Immunity.
10 Introduction (do not write) With so many pathogens, why aren’t you sick all the time?Your body has a protective system; a series of defenses that guard against disease.Like walls that act as barriers & security guards trained to spot invaders.
11 Immune System Primary defense against pathogens Nonspecific defenses Block out everythingSpecific defensesAttack a specific pathogen
12 Nonspecific DefensesFirst line of defense = the skin, mucus, sweat, stomach acidSkin is the most important nonspecific defense.
13 Inflammatory Response Second line of non-specific defensesPathogens may enter body through a cutArea swells, gets redWBC released into injured areaPathogens vs. WBC
14 Inflammatory Response SkinWoundBacteria enter the woundWBCs move into the area and engulf the bacteria and cell debrisCapillary
15 Specific Defenses Powerful defense against a “specific” pathogen. S. defenses produce immunity against pathogens.Two types of immunity: Anti-body & Cell Mediated Immunities.
16 Antibody Immunity Molecules on surface of pathogens called antigens Antigens trigger immune responseB cells (WBC) make proteins called antibodies which stick to antigens
17 Vaccines First vaccine was in late 1700s against small pox Weakened pathogen is injected into bodyBody mounts an immune response without getting sickImmune system develops a memory of the pathogen = permanent immunity
18 Cell-Mediated Immunity Powerful Immune System weapon = Killer T cell.Kill infected body cells.Can cause transplantation rejection.Helper T cells & Suppressor T cells.
19 Immune DisordersTwo main types of disorders: Auto-Immune (overreaction) & Weakening of I.S. (AIDS).Allergies: overreaction to antigen in environment.Histamines are released = inflammatory response.Asthma
20 Auto-Immune Diseases Immune System attacks body’s own cells. Ex - Rheumatoid arthritis & Multiple sclerosis
21 HIV/AIDS HIV attacks T cells Kills T cells = kills immune system New viruses leaving aninfected T cell
22 40.3 “Cancer”Objective:Define Cancer.Identify causes of Cancer.
23 Cancer 2nd leading cause of death in U.S Cancer is uncontrollable cell growth which forms malignant tumors.Caused by mutations, or changes in DNA.
24 CausesVirusesHPV is sexually transmitted and may lead to reproductive cancers.Hepatitis leads to liver cancer.
25 Causes of Cancer... Radiation = UV light from the Sun. Chemicals = carcinogenGeneticsTreatment: surgeries, chemotherapy