1. Everything You Wanted to Know About the Immune System…And More!!!

2. Keeping Pathogens OUT!!! Always exposed to pathogens!
Body destroys most all of them
Remember- some can be good!
But many are bad news!

3. 1st Line of Defense
5 major barriers

4. 5 Barriers Tears- wash them away, chemicals that kill them
Saliva- in your mouth
Skin- protective barrier (can enter through cut, burn, or scrape)
Mucus Membranes- tissues line nose, throat, mouth, eyes, openings (they trap pathogens)
Stomach Acid- acid destroys it

5. Immune System
Immune System- combo of body defenses that are made up of cells, tissues, and organs that fight off pathogens.
kicks in when these 5 barriers
don’t work
1. Non-Specific Response
2. Specific Response

6. Non-Specific Response
When pathogens enter the body, immune system ATTACKS!
**SAME no matter the pathogen**
Inflammatory Response- if pathogen gets past 5 barriers (What are they??)
Phagosytes- special white blood cells that kill pathogens!
How?
- High blood pressure releases proteins that defend the body
Interferons.- the proteins that stop the pathogen from reproducing and helps the cells fight infection.

7. Phagocytes

8. Non-Specific
Inflammation- body’s response to injury or disease, resulting in a condition of swelling, pain, heat, and redness.
**Occurs in the blood and the tissues 
-Fever- happens when the infection spreads through your body. Body heats up- tells your body to make more white blood cells so it’s harder for pathogens to reproduce (fight the disease harder)

11. Specific Response
The pathogen just got through 5 barriers and Non-Specific…
This defense tailored to fight a specific pathogen
Immune system both fights and “remembers” the pathogen so it is more likely to fight it off right away if it ever enters your body again
Lymphatic System: the body uses this system to do it’s specific fighting

12. Lymphatic System Lymphocytes- Special white blood cells in lymph
Secondary circulatory system that helps the body fight pathogens and maintain its fluid balance.
This system circulates lymph, which has many lymphocytes and macrophages in them.
Lymphocytes- Special white blood cells in lymph
B Cells- formed in bone marrow (stop viruses from getting into cells to reproducing)
T Cells- thymus gland (fight existing pathogens)
NK Cells- Natural Killer Cell (attacks cancerous growths)
Macrophages: Phagocytes that help lymphocytes identify these invaders

13. These Lymphocytes are activated when these macrophages recognize the part of a pathogen known as an antigen.
Antigen- substances (part of the pathogen) that send the immune system into action.
Body reacts to these antigens by making Antibodies
Antibodies- proteins connect to antigens, keeping them from harming the body. Makes the antigen so it can’t reproduces

14. Immunity Thats why we get vaccinated- so we can develop antibodies.
Immunity- your body’s ability to resist the pathogens that cause a particular disease
Virus mutes and changes, therefore the previous vaccines are ineffective.