1. Non-specific Immunity- “1st Line” of Defense
Nonspecific immunity- mechanisms of the body that respond to many different pathogens or invaders

2. Nonspecific Immunity Prevent or destroy pathogens
Attacks anything that is considered “not self”- viruses, bacteria, prions
Attacks pathogen immediately
General defense

3. Mechanisms Involved
1. Species Resistance- genetic characteristics which prevent an organism from contracting a disease
Ex. Dogs cannot contract mumps
2. Mechanical Barriers- “castle wall” of our body of densely packed cells and other materials which protect from invasion, sloughed off (10B skin cells/day=250 g./year)
Ex. Skin, mucous membranes
If either is broken, pathogens can enter.

4. “First Line” of Defense
Mechanical barrier on all surfaces of body exposed to external world
What are they?
Skin
Mucous membranes—nasal, respiratory
Lining of mouth
Lining of gut
Lining of vagina/urethra
Surface of eye

5. Barrier Membranes
Skin

6. Mechanisms Involved
3. Chemical Barriers- chemicals that interfere with the production of a pathogen
Ex. Mucus- sticky, traps pathogen
Enzymes- proteins that destroy pathogen
HCl- stomach acid- lowers pH to kill pathogen
4. Resident microbes-have commensal or mutualistic bacteria and fungi that are normally present and out-compete potential pathogens

8. Lymphatic/1st Line of Defense Review
List 2 of the 4 mechanisms that make up the 1st line of defense.
Name the 2 mechanical barriers.
What organ is responsible for filtering lymph?
_______________ immunity makes up the 1st line of defense.
The thoracic duct drains what portion of the body?
Saliva and enzymes are part of the _____________ barriers of the 1st line of defense.

9. Second Line of Defense Fever Inflammation Phagocytosis
NONSpecific- All work tightly with specific immunity

10. Fever Pluses Inhibit microbial growth Enhance immune cell performance
Trigger not completely understood
Muscular contraction and constriction of skin blood vessels cause core temperature to rise
Pluses
Inhibit microbial growth
Enhance immune cell performance
Speed tissue repair
Minuses
Malaise
Body aches
chills
“Breaking” fever or “crisis of fever”:
body begins to cool by sweating,
“color returns” as blood vessels in skin open
Indicates infection is overcome

11. Inflammation
Response to tissue damage from any source (burn, cut, pathogen, other??)
4 Cardinal Signs-
redness- inc. blood volume
swelling- inc. capillary permeability Phagocytes migrate out of capillaries
Heat- inc. blood from deep within body
Pain- stimulates pain receptors

12. Phagocytosis
Phagocytes move through blood and lymph and into connective tissues and engulf and destroy cells or pathogens
Ex. Neutrophils and monocytes

13. Langerhans cells in skin
Phagocytes in blood
Microglial cells in CNS

15. Great review of “Body Defenses” or Non-specific Immunity

16. 2nd line of Defense Name the 4 parts of the 2nd line of defense.
Is the 2nd line Nonspecific or specific?
_____ increases phagocytic cells
_____ is the tissue response to injury.
4 signs of inflammation?
Increase in ______ volume causes redness, swelling, and heat.
Stimulation of _____ receptors cause pain.
The process of WBCs to engulf and destroy pathogens is_______.
A WBC responsible for phagocytosis is a _________.