Immune System

1
Immune System Disease

• Chapter 31

2
In the 1850s Pasteur proposed the Germ Theory
Specific microorganisms cause disease

• Types of pathogens that cause disease.
• Bacteria
• Viruses
• Fungi- occur in warm damp areas
• Protozoa
• Parasites

3
How are Bacteria and Viruses Different?
4
BacteriaThe Prokaryotes

• Reproduce by Binary Fission

• Autotrophic and Heterotrophic

5
HelpfulBacteria in Nature

• Decomposers
• Nitrogen cycle
• Industry
• Food- yogurt!

6
Harmful BacteriaCause disease by

• Releasing toxins into the body
• Directly break down tissue of organism for food

7
VirusesLatin for Poison

• Not living
• Require a host cell to reproduce!!
• Consist of DNA or RNA surrounded by a protein
  coat

8
Viral Infection

• Virus enters host cell
• Host cell produce viral DNA
• Host cell bursts

9
Retroviruses

• Viruses that have RNA as their genetic material
• HIV leads to AIDs

HIV kills our Helper T cells
10
Common Viruses

• Flu
• Chicken Pox
• Warts
• Mono
• Rabies

11
Treatment
Viruses
Bacteria

• Antibiotics
• Vaccination

• Vaccination

Immunity from vaccination can be temporary or
permanent
12
How our Bodies defend against pathogenic organisms
Nonspecific vs. specific defenses
13
Nonspecific 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

14
Types of Immunity
Active
Passive

• 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

15
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

16

• Antibodies help kill the intruder by
• 1. Binding to antigens
  on surface of microbes
• 2. Clustering antigens together