what are the 4 methods of disease transmission? › uploads › 1 › 2 › 6 › 9 › 126982995...

What are the 4 methods of disease transmission?

• Direct Transmission• Ex: Shaking hands, sharing drinks, etc. (you directly

touch an infected human or their blood/body fluids)

• Indirect Transmission• Ex: Sneezing or coughing (there is no direct contact

between you and the infected person…the pathogen is spread through the air before landing on you)

What are the 4 methods of disease transmission?

• Contaminated Food or Water• Ex: eating meat that has not been prepared properly

or drinking water that contains pathogens (not the same as sharing drinks with a sick person…the water is not contaminated, the person’s saliva is!)

• Animal Bites• Ex: An animal that carries a pathogen bites you and

transfers the pathogen to your blood

What is the purpose of the first line of defense?

Prevents pathogens from infecting your body

How does the skin play a role in the first line of defense?

A physical barrier to stop pathogensSweat and oils on the skin are acidic and prevent pathogens from growing

How does the respiratory system play a role in the first line of defense?

Cilia (hairs) in your nose trap pathogens before they can enter your body.Mucous traps pathogens. You get rid of the mucous (and pathogens inside) by coughing or sneezing.

How does the digestive system play a role in the first line of defense?

Gastric juices (stomach acid) kill pathogens that you may have eaten.

What are the 5 ways that pathogens can enter your body?

EyesMouthEarsNoseBlood

1. When does the second line of defense kick into action? What is the purpose of the

second line of defense?

• The second line of defense kicks into action when a pathogen gets past the first line of defense (enters the body)• Purpose: a quick & non-specific attack on

pathogens

2. What kind of cells will the immune system recognize and attack?

• Any cells that do not belong to your body

3. What is inflammation? What causes it?

• Swelling & redness• Caused by fluid being brought to the site of an

infection

4. What is a phagocyte?

• A white blood cell• Recognizes and "eats" pathogens

5. What other reaction(s) might be caused by the second line of defense?

• Fever• Remember – bacteria are picky about where

they live. A fever is the body's way of making the body "unlivable" for bacteria

6. What is an antigen?

• Anything that the body does not recognize• Pathogens have antigens on their surface that

the immune system recognizes as "foreign" (not you) and will cause an immune response

7. What is the purpose of the third line of defense?

• A specific & targeted attack on a specific pathogen/antigen• Different pathogens/antigens mean a different

response from the third line of defense

8. How is the third line of defense different from the second line of defense?

• Specific• 2nd line is general (the same for all

pathogens/antigens)

• Takes longer to develop• 2nd line is immediate

• Built up over our lifetime• We are born with 2nd line ready to go

9. What is faster, the innate or acquired immune response? Why?

• Innate immune response (2nd line of defense)• It is general – always the same for every

pathogen/antigen and therefore always ready to go!

10. What are Plasma B Cells? What do they do?

• A type of white blood cell in the 3rd line of defense• They create antibodies

11. What is a pathogen?

• A pathogen is any living organism that can cause disease or illness• Bacteria, fungi, protist, virus• Ex: E. Coli, Salmonella

12. What is an antibody? What do they do? Where might they be found?

• Antibodies are molecules produced by B cells that attach to antigens• Antibodies "attract" phagocytes and tell them

which cells to "eat"• Antibodies also prevent pathogens from

entering cells• They are found on the outside of pathogens,

attached to antigens

13. What are the two types of T cells? What do they do? How are they similar? How are

they different?

• Helper T Cells and Killer T Cells• They are both part of the 3rd line of defense

(acquired immune response)• Helper T Cells recognize antigens and activate B

Cells to produce more antibodies• Killer T Cells recognize antigens and can destroy

invader cells without the help of B Cells or Phagocytes

14. What are Memory B Cells

• Memory B Cells store copies of antibodies produced by the Plasma B Cells• This way if your body encounters the same

antigen again, the Acquired Immune Response will already know how to defeat it

15. What is immunity?

• After an attack from a certain antigen, your body stores antibodies in Memory B Cells• If you are attacked by that antigen again, your

body will be able to defend itself right away and you will not get sick

https://www.youtube.com/watch?v=zQGOcOUBi6s