1. Reaves
31.2 – 31.4 Immunity

2. KEY CONCEPT: The immune systems consists of organs, cells, and molecules that fight infections

3. Many other tissues and systems help the immune system
Skin is a physical barrier to infection
Mucous membranes trap pathogens entering the body
The circulatory system transports immune cells

4. Cells and proteins fight the body’s infections.
White blood cells attack infections inside the body
Phagocytes engulf and destroy pathogens
T cells destroy infected cells
B cells produce antibodies

5. Three types of proteins fight off invading pathogens
Complement proteins weaken pathogen membranes
Antibodies make pathogens ineffective
antibody
pathogens
Interferons prevent viruses from infecting healthy cells

6. Immunity prevents a person from getting sick from a pathogen.
When you have immunity, pathogens are destroyed before you get sick
Passive immunity occurs without an immune response
mother’s milk
genetics
Active immunity occurs after a specific immune response

7. On your notes!
Create a Y-chart : Passive and Active Immunity p760

8. KEY CONCEPT The immune system has many responses to pathogens and foreign cells.

9. Two types of responses # 1 Nonspecific Responses-the same for every pathogen
Inflammation
blood vessels become leaky.
white blood cells move toward infection and damaged tissue
capillary wall
extracellular space
white blood cell
D. characterized by swelling, redness, and pain
E. Fever-body temperature increases.
Low fevers stimulate white blood cells to mature.
High fevers can cause seizure, brain damage, and even death.

10. 2. Specific Responses
1st detect antigens (surface proteins on pathogens)
Each pathogen has a different antigen.
virus
antigens

11. Two types of specific immune responses.
A. Cellular immunity uses T cells to destroy infected body cells.
pathogen
antigens
T cell
receptors
activated T cells
memory T cells

12. B. Humoral immunity uses B cells to produce antibodies.
T cell
pathogen
memory B cells
activated B cells
antibodies

13. Both responses produce memory cells.
B cell
T cell
specialized T and B cells
provide acquired (active) immunity

14. The immune system rejects foreign tissues.
Tissue rejection occurs in organ or tissue transplants.
Tissue rejection is the result of an immune response.
immune system detects protein markers on the donor tissue
makes antibodies against the donor’s tissue

15. Stop!
Complete 31.3 Power Notes

16. KEY CONCEPT Living in a clean environment and building immunity help keep a person healthy.

17. Many methods are used to control pathogens.
Antibiotics and antiseptics cause pathogens to burst.

18. Antiseptics kill pathogens outside of the body.
do not target specific pathogens
examples include vinegar and soap
Antibiotics kill pathogens inside the body.
target one specific bacterium or fungus
not effective against viruses

19. Antibiotic resistance can cause medicines to become ineffective.
Some bacteria in a population have genes that make them immune to antibiotics.
These bacteria spread the gene, making the antibiotics useless.
A bacterium carries genes for antibiotic resistance on a plasmid.
A copy of the plasmid is transferred through conjugation.
Resistance is quickly spread through many bacteria.

20. Vaccines artificially produce acquired immunity.
Vaccines also control pathogens and disease.
given to prevent illness
contain the antigen of a weakened pathogen
Vaccine Article

21. 9. What is a vaccine?
A substance that produces active immunity.
What do vaccines do that allow the body to gain immunity without getting sick?
Produce memory cells
11. Memory cells do not have to be activated- they respond right away.
12.Vaccines are made of : dead, whole pathogens, weak pathogens, pieces of pathogens, bacterial toxins

22. Vaccination provides immunity. stimulates a specific immune response
Antigens in a vaccine trigger an immune response, and memory B cells are made. 1
memory B cells
causes memory cells to be produced
A memory B cell is stimulated when the real pathogen binds to it. 2
allows immune system to respond quickly to infection
The B cell quickly activates and makes antibodies that fight the pathogens before you get sick. 3
has such a fast response, a person will not get sick

23. Stop! The Science Behind the Flu Shot Work in pairs.
Turn in one answer sheet per pair. (Add both names to sheet!)