1. Immune System

2. 3 lines of defense: Immune System First line – Barriers
Ex: Skin, saliva, tears
Second line – Internal non specific
Ex: Phagocyte (cell eater), antimicrobial proteins, inflammatory response
Third line – Targeted (specific)
Ex: B cells, T cells, memory cells, antibodies

3. Immune System Non Specific Specific
Non Specific Response = 1st and 2nd line of defense - same regardless of pathogen
Specific Response = 3rd line – very specific, targeted to the pathogen

4. First Line of Defense External
Skin: Constantly shedding, outer layer = tough dead cells (hard to get through)
Sweat and oil glands: secrete oils and acids that prevent growth of colonies
Saliva, tears: contain lysozome, an enzyme that breaks down bacterial cell walls

5. Second Line of Defense Internal
Antimicrobial Proteins
Prevent bacteria from reproducing
Phagocytes
White blood cells that engulf (eat) invaders
Inflammatory Response
Delivers proteins and phagocytes
GENERAL, NONSPECIFIC!
(WORKS ON A WIDE RANGE OF PATHOGENS)

6. Inflammatory response:
Occurs with injury to a tissue
Response to chemical signals (histamines)
More blood flows to area, resulting in redness, swelling, sometimes fever
Delivers antimicrobial proteins and phagocytes

7. Types of white blood cells crucial for the immune response
Third Line of Defense
B Cells and T Cells
Types of white blood cells crucial for the immune response
They have receptors that recognize the antigen, a structure that triggers the immune response (often found on pathogens).

8. B and T cells
When they recognize the pathogen, they bind to it, then reproduce. When they reproduce, they create:
Effector / Plasma Cells Fighter cells that attack the pathogen
Memory cells launch quicker immune attack in the future
T Cells
Helper T Cells activate B and T cells to reproduce/attack.
Killer T Cells destroy body cells that have been infected by a pathogen
B Cells
Make antibodies that can bind to pathogen and prevent it from entering and infecting cells, or can bind to pathogen and flag it for phagocytosis

9. Antibodies Made by B Cells
Are specific to certain pathogens (fit like a key in a lock)
Can work by:
1. Sticking to pathogen and preventing it from infecting cells
2. Flagging pathogen for WBC to kill them
3. Working with proteins to destroy the germ

10. How do vaccines work? (add this info in a margin)
Vaccines give your body a dose of the pathogen
Your immune system launches an attack by making antibodies and memory cells