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

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

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.

“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

Barrier Membranes Skin

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

Lymphatic/1 st Line of Defense Review 1.List 2 of the 4 mechanisms that make up the 1 st line of defense. 2.Name the 2 mechanical barriers. 3.What organ is responsible for filtering lymph? 4._______________ immunity makes up the 1 st line of defense. 5.The thoracic duct drains what portion of the body? 6. Saliva and enzymes are part of the _____________ barriers of the 1 st line of defense.

Second Line of Defense Fever Inflammation Phagocytosis All work tightly with specific immunity

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

Inflammation Response to tissue damage from any source (burn, cut, pathogen, other??) 4 Cardinal Signs- 1.redness- inc. blood volume 2.swelling- inc. capillary permeablility Phagocytes migrate out of capillaries 3.Heat- inc. blood from deep within body 4.Pain- stimulates pain receptors

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

Langerhans cells in skin Phagocytes in blood Microglial cells in CNS

Links to Specific Immunity Phagocytosis continues to be common way to kill pathogenic cells in both specific and non- specific response Inflammation works to allow both specific and non-specific immune response to accelerate Fever also allows for better performance in both specific and non-specific function Specific immune response and “antigen presentation” further stimulates non-specific actions like phagocytosis, complement.

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

2 nd line of Defense 1.Name the 4 parts of the 2 nd line of defense. 2.Is the 2 nd line Nonspecific or specific? 3._____ increases phagocytic cells 4._____ is the tissue response to injury. 5.4 signs of inflammation? 6.Increase in ______ volume causes redness, swelling, and heat. 7.Stimulation of _____ receptors cause pain. 8.The process of WBCs to engulf and destroy pathogens is_______. 9.A WBC responsible for phagocytosis is a _________.