1. PHYSICAL BARRIERS & IMMUNE SURVEILLANCE
Celia, Darian, Lindsey, and Kathy

2. PHYSICAL BARRIERS

3. Purpose
To prevent entry of bacteria and other substances or harmful toxins into the body
Non-specific immune responses are often more rapid than specific immune responses

4. Examples
Tears
Wash harmful substances from the eyes and traps foreign material in the mucous membrane of the eye
Sweat
A natural antibacterial
Increases the pH of your skin to 3-5pH.

5. Examples cont... Skin First defense of the innate immune system
Acidity of our skin serves to kill foreign pathogens
Cuts and burns allow pathogens to penetrate the skin

6. Mucous Membrane Examples cont...
Can trap pathogens, which are then sneezed, coughed, washed away, or destroyed by chemicals
Lines all body cavities open to the exterior and function as an additional physical barrier.
Examples cont...

7. Examples cont...
Saliva
Contains digestive lysozymes that destroy bacteria
Stomach Acids
Destroy pathogens through secreted hydrochloric acid solutions and protein digestive enzymes

8. First Lines of Defense

9. IMMUNE SURVEILLANCE

10. The immune system patrols the body to recognize and destroy invading
1) pathogens AND 2) cancerous host cells

11. IMMUNE SURVEILLANCE PROCESS (general)

12. IMMUNE SURVEILLANCE definitions
Natural Killer Cell (NK)
Lymphocyte
Innate (nonspecific) immunity
Perforin
“Pore forming protein”
Found in NK
Binds to enemy cell’s plasma membrane and forms a pore
Pore lets granzymes into enemy cell
“Doorman”
Granzymes
“Killer enzyme”
Found in granules of NK
Induce cell death
“SWAT team”
*Granules: tiny secretory vesicles

13. IMMUNE SURVEILLANCE PROCESS (general)

14. IMMUNE SURVEILLANCE IN CANCER DETECTION
T Cell Receptors
Antigens on the tumor cells are recognized by the T cell receptors
Activated T Cells
Can kill the tumor cells and then are referred to as Cytotoxic T Cells and Natural Killer Cells
T Helper Cells
Aid in the activation of T Cells and Natural Killer Cells
Send signals to stimulate the T Cells and the Natural Killer Cells

15. IMMUNE SURVEILLANCE PROCESS in response to cancer
INTERFERON
inhibits cancer cell mitosis
CANCER CELLS
enhances
directly attacks &
destroys
CYTOTOXIC T Cell
NATURAL KILLER Cells
MACROPHAGES
secretes

16. CYTOTOXIC T cells NATURAL KILLER MACROPHAGES
secrete toxic chemicals (exocytosis)
NATURAL KILLER
secrete toxic chemicals (exocytosis)
MACROPHAGES
engulfs pathogens (phagocytosis)