1. LO: SWBAT explain how our body defends us from pathogens.
DN: Quiz: immune #1
HW: Have a great weekend!!!
Thursday 1/30- Quiz on immune system

2. DO NOW QUIZ Explain what a pathogen is.
Give two examples of types of pathogens and give a specific example for each type.
Will a Dr. give you antibiotics if you have a cold? Why or why not?

3. Pathogens
Any disease-producing agent such as a virus, bacterium, fungus, or parasite.

4. 1st Line of Defense Skin enzymes in sweat Mucus trap pathogens
Tears in eyes
enzymes to destroy pathogens
Acid in stomach
- inhospitable to pathogens
Show an apple and discuss the skin’s job.

5. 2nd Line of Defense
The Immune
System

6. White Blood cells Large cells with a nucleus.
Less numerous than RBC’s.
Defenders of the body.
Types:
a. Phagocytes: engulf and destroy bacteria
b. Lymphocytes: produce antibodies

7. Immune System
Made of proteins, cells, and tissues that identify and defend the body against pathogens

8. How does our immune system identify foreign cells?
A protein on the cell
The ID tag identifies the invader as not belonging to the body (non-self).
This ID tag is called an antigen.
I.D. Tag
Antigen

9. Phagocytes Engulf the Pathogens
White blood
Cells that
eat pathogens

10. Lymphocytes Produce antibodies
They can make antibodies, which are their weapons against the foreign antigens.
Antibodies & Antigens are both proteins!!

11. Antibodies: Lymphocytes
Also called B Cells
They are “Y” shaped proteins, made by __________
They are weapons that fight against pathogens
Lymphocytes
Pathogen
Antibodies
Use screw motivation
Antigens

12. How do antibodies destroy pathogens?
When the antibody attaches to the antigen, it breaks open its cell membrane
Or, the antibody attaches to the antigen, and a phagocyte will know to engulf it
Balloon and pin motivation

13. Our Immune System has a good memory!
*The first response is
relatively slow and
weak because time
is needed for enough
WBCs to form and
defeat the pathogen.
*The second response
to the same pathogen
triggers a quicker and
stronger response.
*After the first response, the immune system “remembers”
specific pathogens by leaving behind WBCs that protect the body for years (memory cells).

14. How are nuts and screws similar to antigens and antibodies?
Antibodies are made specifically to
match the shape of the antigen.
1 antigen = 1 antibody
What does this remind you of?
Do screw and nut motivation