1. Fighting Disease

2. Harmful Bacteria
Parasitism  when bacteria benefits at the expense of the host Example: Pathogen – a disease causing microorganism

3. Pathogenic Bacteria gain entrance into the body
bacteria begins to produce toxins
toxins travel through body via circulatory system
results is illness/disease
EXAMPLES: Tuberculosis, Typhoid, Diptheria

4. THREE LINES OF DEFENcE
There are 3 lines of defence offered by the immune system
External Defence
Lymphatic System
Antibody Formation

5. External Defence Bacteria cannot penetrate human skin
Bacteria can enter through pores, wounds, openings (nasal cavity and mouth) and eyes
Nasal Cavity and pharynx have cilia and mucus that will trap bacteria
In eyes, bacteria are destroyed by enzymes in tears

6. Lymphatic System Works closely with the circulatory system
As microorganisms are collected in the lymphatic system they are destroyed by specialized white blood cells called lymphocytes
Macrophage – WBC that engulfs
and digests foreign bacteria
Pus – mass of dead WBC
and bacteria

7. Antibody Formation
Antibody: protein molecules that inactivate foreign substances by binding to its surface
Antigen: the foreign substance that causes disease
Each antigen has a specific antibody that will bind to it
Our bodies can only create antibodies to disease causing agents that we have previously been exposed to
ANIMATION: Immune System Response

8. immunity
An immune response is the production of antibodies to counteract a pathogen
Active Immunity
body produces antibodies to combat a specific disease  lifelong
Can be achieved through vaccines
Passive Immunity
Antibodies are directly injected in bloodstream
Babies acquire immunity through their mothers
Babies will eventually need vaccinations to strengthen their immunity

9. Vaccines vs. antibiotics
designed to kill pathogenic bacteria ONLY
Doctor will get a sample of the affected area and send it for testing before prescribing antibiotics to make sure it is a bacterial infection
Take antibiotics until it is finished to make sure the bacteria is eliminated from the body

10. Vaccines vs. antibiotics
Weakened strain of bacteria or virus that will increase active immunity (create antibodies)
Once pathogenic bacteria and virus enters the body, antibodies recognize it, bind to it and macrophages destroy it before it causes damage to our bodies