Immune System & DiseaseImmune System & DiseaseChapter 31

In the 1850’s Pasteur proposed the

Germ TheoryGerm Theory Specific microorganisms cause disease

Types of pathogens that cause disease.

Bacteria

Viruses

Fungi- occur in warm damp areas

Protozoa

Parasites

How are Bacteria and Viruses Different?

BacteriaThe Prokaryotes

•Reproduce by Binary Fission

•Autotrophic and Heterotrophic

HelpfulHelpfulBacteria in NatureBacteria in Nature

Decomposers

Nitrogen cycle

Industry

Food- yogurt!

Harmful BacteriaCause disease by

Releasing toxins into the body

Directly break down tissue of organism for food

VirusesLatin for Poison

• Not living

•Require a host cell to reproduce!!

•Consist of DNA or RNA surrounded by a protein coat

Viral Infection

Virus enters host cell

Host cell produce viral DNA

Host cell bursts

RetroviruseRetrovirusess

Viruses that have RNA as their genetic material

HIV leads to AID’s

HIV kills our Helper T cells

Common Viruses

Flu

Chicken Pox

Warts

Mono

Rabies

TreatmentTreatmentTreatmentTreatment

Antibiotics

Vaccination

Antibiotics

Vaccination

VaccinationVaccination

Bacteria Viruses

Immunity from vaccination can be

temporary or permanent

How our How our Bodies defend Bodies defend

against against pathogenic pathogenic organismsorganisms

Nonspecificvs.

specific defenses

Nonspecific DefenseNonspecific Defense

Skin- the most important!Oil and sweat create an

acidic environment

Mucus, saliva, sweat, tears, contain lysosomes that break down bacterial cell walls

Inflammatory response- fever and swelling

Types of ImmunityTypes of Immunity

Body mounts an active response to the pathogen

The development of antibodies in response to stimulation by an antigen

Produced by vaccination or getting the disease

Body mounts an active response to the pathogen

The development of antibodies in response to stimulation by an antigen

Produced by vaccination or getting the disease

Temporary immunity

A mother provides passive immunity to her baby in her uterus and after birth by breastfeeding

Temporary immunity

A mother provides passive immunity to her baby in her uterus and after birth by breastfeeding

Active Passive

Specific DefenseThe Antibody Antigen Reaction

Specific DefenseThe Antibody Antigen Reaction

An antigen triggers an immune system response

Antigens are specific for each pathogen

Lymphocytes produce antibodies.

Once formed the antibodies are held in memory B cells (lymphocytes) so that the body has permanent immunity to that disease

An antigen triggers an immune system response

Antigens are specific for each pathogen

Lymphocytes produce antibodies.

Once formed the antibodies are held in memory B cells (lymphocytes) so that the body has permanent immunity to that disease

• Antibodies help kill the intruder by:

1. Binding to antigens on surface of microbes

2. Clustering antigens together