Immune System & Disease

Mrs. GeistBiology, Fall 2010-2011Swansboro High SchoolImmune System & DiseaseDiseaseCommunicable disease: a disease that can be easily passed from one person to another through close contactEx: herpes, malaria, mumps, HIV/AIDs, influenza (flu), chicken pox, ringworm, whooping coughNon-communicable disease: a disease that cannot be easily passed from one person to another through close contactEx: diabetes, high blood pressure, cystic fibrosis, PKU, hemophilia, cancerThe genes you inherit from your parents can make you more likely to develop a non-communicable diseaseSickle Cell AnemiaNon-communicableRecessively inheritedRed blood cells shaped like crescents and deliver less oxygen to the bodyMore common in people of African and Mediterranean descentCarriers have resistance to malaria

MalariaCaused by the protist called PlasmodiumTransmitted via mosquitoesRed blood cells rupture anemiaLiver and kidney failure

Lung/Mouth CancerNon-communicableUncontrolled cell growth in the tissues of the lung or mouthmain causes: carcinogens (such as those in tobacco smoke) & radiation

Skin CancerNon-communicableUncontrolled cell growth of abnormal skin cellsKnown risk factors: light complexion, family history, sun exposure and sunburn, over the age of 40

DiabetesHigh blood sugar levelsNon-communicableCaused by too little insulin, resistance to insulin, or bothInsulin is the hormone produced by the pancreas that controls blood sugar

Phenylketoneuria (PKU)Missing enzyme to break down an amino acid called phenylalanineBuilds up in the brain brain damagePhenylalanine found in NutraSweet (aspartame)Recessively inheritedNon-communicable

Kochs PostulatesKochs Postulates: 4 experimental steps for directly relating a specific pathogen to a specific diseasePathogen must be found in the host in every case of the diseasePathogen must be isolated from the host and grown in a pure culture (contains no other organisms)When the pathogen from the pure culture is placed in a healthy host, it must cause the diseaseThe pathogen must be isolated from the new host

Kochs Postulates

Immune ResponseHistamine: causes capillaries to expand and blood flow to increase, which causes inflammation (swelling) in the damaged areaLocalizes the infectionAllows the body to destroy pathogen and repair damaged tissueFever: increase in overall body temperatureSlows the growth of bacteriaIncrease the production of disease-fighting cellsThe Immune ResponseInnate ImmunityProvides general protection against various pathogensSkin- provides a physical barrierMucus- prevent various areas of the body from drying out and trap microorganisms and other foreign substances in the respiratory and digestive tractGastric juice- destroys most bacteria and their toxins in the stomachSweat, tears and saliva contain lysozyme, an enzyme that breaks down bacterial cell walls

Innate Immunity

Immunity: ability to resist diseaseActive immunity: acquired naturally when a person is exposed to antigens and produces antibodies specifically to these antigensLong-termPassive immunity: antibodies are introduced in the bodyMother transfers antibodies to an infant through breast-feedingInject a person with antibodies (ex: anti-venom)

Antibodies & AntigensAntigen: foreign substance in the bodyEx: virus, bacteria, toxin, or a piece of these foreign substancesAntibody: proteins created by white blood cells in response to an antigenSpecific to one antigenEx: measles antibody will only combine with a measles antigen

VaccinationsVaccine: weakened, dead, or pieces of pathogens or antigens that cause an immune response when they are injected into the body. 1790s Edward Jenner- developed a smallpox vaccine. Infected a boy with cowpox, a disease that is similar to, but milder than, smallpoxBoy developed immunity to smallpoxLymphatic systemDefends the body against disease & maintains homeostasis by keeping body fluids at a constant levelLymph vessels contain fluid called lymph.Lymph node: small mass of tissue that contains lymphocytes and filters pathogens from lymphLymphocyte: a type of white blood cell that defends the body against foreign substancesTonsils: provide protection against pathogens that enter your nose and mouthSpleen: stores certain types of lymphocytes & filters blood.

Lymphatic system

Lymphatic system Thymus gland: stores immature lymphocytes until they matureT cell: lymphocyte that is produced in bone marrow and stored in thymus gland.Helper T cells: activates B cellsKiller T cells: release enzymes into pathogens, causing them to lyse and dieB cell: produces antibodies. Activated by Helper T cells. NutritionNutrients: substances needed by an organism to carry out life functionsEx: carbohydrates, fats, proteins, nucleic acids, vitamins, and trace mineralsAn organism in good health is more likely to fight off diseases and remain healthy.

ActivityRead p. 218 in EOC review books and respond to the activity questionSkim through Chapter 11 (pp. 209-219). Answer Part B on p. 214.Parts B & C on p. 220. Answer Ch. 11 Review Questions on pp. 221-222.