1. Understanding Disease

2. Disease: Any condition that interferes with the proper functioning of the body and mind. Two Types of Disease Communicable A disease that can be passed to a person from another person, animal, or object via a pathogen (germ), entering the body. Non-Communicable Disease A disease not capable of being passed on.

3. 4 Types of Pathogens 1.Virus: The smallest pathogen such as a cold or flu. Cannot be treated with antibiotics. 2.Bacteria: Tiny, one-celled organisms such as strep throat. Most can be cured with antibiotics. 3.Fungi: More complex than bacteria and cannot make their own food. Example, Athlete’s Foot. 4.Protozoa: One-celled organism. Example, Malaria may be transferred into the body from an infected mosquito.

4. Pictures of Pathogens Bacteria Fungi Virus Protozoa Virus

5. Modes of Transmission How do the pathogens get passed on? 1.Direct Physical Contact - Ex: handshake, kiss… 2. Indirect Contact – Ex: doorknob, utensils… 3.Airborne – Breathing in droplets/spray from others coughing or sneezing into the air. 4.Transmission by animal or insect.

6. So…… What does the body have that fights off these pesky pathogens once they’ve launched an invasion on us?

7. The Immune System The Immune System is the body’s defense against infectious diseases. It’s made up of cells, tissues, and organs that work together to protect the body. Key Players: White Blood Cells, Macrophage, Antigens, Helper T cells, B Cells, Killer T Cells, Antibodies, Memory Cells

8. The Immune Response http://www.youtube.com/watch?v=WJEc2GDEfz 8

9. The Chain of Command Macrophage: Recognizes the germ has invaded & doesn’t belong. It swallows it up and “flags” the cell. This flag is an antigen, or a small piece of the virus. Helper T Cells: Recognize the antigens on the cell. They release a chemical message that signals other cells to the area to help battle the pathogen.

10. Help is on the way! B Cells: Answer the call of the Helper T’s. They form “Y” shaped antibodies that tag, or attach to the pathogen, that show it’s the germ that needs to be destroyed. Killer T Cells: They come in to swallow up the tagged pathogen to rid the body of it. Lastly… Memory Cells: They stay behind to make sure that same germ doesn’t attack again. If it does, they alert the antibodies to kill it off without having to go through the whole process from the beginning.

11. Is it over now? *Once all the battling is over, the body will recover to its healthy self. *The length of the disease will vary depending on the type of pathogen and how healthy the Immune System is prior to the invasion. *Eating healthy, exercise, rest, and drinking plenty of water are all ways to help keep your Immune System strong..