Immunity From Disease Chapter 39 - PowerPoint Presentation

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Immunity From Disease

Chapter 39Slide2

disease

Disease-any condition that impairs the normal functioning of the body

Violation of homeostasis

Homeostasis-ability of the body to keep proper internal conditions no matter what is happening outside of itCan be infectious or non-infectious Infectious diseases are typically caused by pathogens Bacteria, protists, fungi, viruses, prions, worms, etc.Non-infectious diseases are usually the result of errors within the bodyCancer, heart disease, etc.The line between the two is blurrySome infectious agents can lead to non-infectious diseasesViruses can alter the cell cycle and lead to cancerSlide3

infectious diseases

Any disease caused by the presence of pathogens in the body

Can be transmitted to others

Contagious-Disease that spreads from one organism to another through close proximityDoes not even require contactCOMMUNICABLE-DISEASE THAT CAN SPREAD FROM PERSON TO PERSON, BUT NOT USUALLY SPREAD THROUGH EVERYDAY CONTACT Example: herpes Slide4

The germ theory of disease

People once thought that spirits caused disease

Holes were drilled in infected people’s heads in an attempt to release the evil spirits

In 1857, French scientist louis Pasteur made the connection between microorganisms and diseaseHe hypothesized that the disease could be eliminated if the organism was eliminatedMany people did not accept the theorySlide5

Joseph lister

1865

British surgeon

Noticed that about ½ of his patients dies from infections, even after successful surgery Heard about Pasteur’s theory and began doing something drasticWashing his hands…The number of infections dropped dramatically (nearly 0)He published his crazy hand-washing idea and encouraged his students and fellow surgeons to practice more sanitary methodsYes, Listerine is named after himSlide6

Robert Koch

1883

German physician

Found that he could make organisms sick by injecting it with pathogens from a sick animalCame up with 4 conditions that must be met before one can conclude that that a certain pathogen causes a diseaseCalled Koch’s postulates Slide7

Koch’s postulates

The pathogen must be found in every case the disease is found

The pathogen must be isolated and grown in a pure culture

Healthy organisms infected with the culture must develop the diseaseThe pathogen must be isolated from the second organism and found to be identical to the firstSlide8
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Spread of infectious diseases

The main source of human pathogens is the human body itself

Carriers-someone who passes the illness on without being infected themselves

Some diseases can be transmitted by other species Zoonotic diseasesOther diseases can be found in the environmentDirt, water, etc.Slide10

Transmission of disease

Can be transmitted 4 ways

By direct contact

By an objectThrough the airBy an intermediate organismCalled a vectorSlide11

Innate immunity

Skin and body secretions

Skin is the first barrier against infection

The organism must gain entry to your body to infect youMucus, skin oil, sweat, tears, and saliva also protect youAll have the ability to break down the cell wall of bacteriaInflammation of body tissues Local Redness, swelling, pain, and heatWhite blood cells release histamine Histamine dilates blood vessels, allowing other W.B.c. to come and attack the invaders Slide12

Innate immunity continued

The white blood cells that come in response are phagocytes

Phagocytes are cells that are able to engulf and destroy pathogens (called phagocytosis)

Lysosomal enzymes digest the particles After killing the pathogens, the phagocytes dieThe collection of dead WBC and fluids form pusInterferons (protective proteins) also help protect against viruses Slide13

Acquired immunity

Defense against a specific pathogen by gradually building up a resistance to it

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nd line of defense against diseaseTwo kinds of immune responses: Antibody immunity and cellular immunitySlide14

Antibody immunity

One type of acquired immunity

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st, your innate immunity does its jobPhagocytes attack the pathogenThey then display the antigens (foreign particles that innate an immune response) on their surface.Helper T cells have receptor cites that recognize and bind to the antigensPlasma cells secrete antibodiesThe antibodies attach to and neutralize pathogensThey then call phagocytes to help destroy neutralized pathogensSlide15

Cellular immunity

Similar to antibody immunity

Does not produce antibodies

Create killer T cells (cytotoxic)These T cells attach to and lyse (destroy) pathogensSlide16

Allergic reactions

If your immune system overreacts to foreign substances (such as dust or pollen), it can release massive amounts of histamines

These cause the symptoms of allergic reactions

Sneezing, increased mucus production, rednessYour body can also mistake your own cells as foreign and attack your own tissuesCalled an autoimmune disorderarthritis Can also attack transplanted tissuesSlide17

Passive and active immunity

Acquired immunity can be active or passive

Passive immunity

Antibodies can be transferred from mother to child through placentaInjecting antibodies from other organism immune to the diseaseOccurs with antivenomsActive immunityCaused by exposure to antigensRecovering from an infectionVaccines Injecting dead, weakened, or incomplete portions of pathogens to cause an immune responseSlide18

Edward jenner

Developed the first vaccine

Smallpox

Injected cowpox, a less harmful, yet similar, disease, into a childThen injected that child with smallpox, an extremely deadly diseaseThe child did not get infectedSaved many, many lives