Non specific host defense
Resistance (cannot get that disease) Specific resistance (resistant to one particular microbe) Non-specific resistance (will work against everything) innate resistance, and susceptibility.
1st line of defense
Superficial surface (intact skin and mucus membranes and their secretions)
2nd line of defense
Veins and capillaries complement; blood thirsty, theres 26 of them in your blood. Works non and helps out with specific goes to enemy pathogen, sticks in proteins and pathogens dimenish. (Phagocytic WBC's, inflammation, fever, complement, and interferon)
Lysozymes (targets Gram +), Acids and electrolytes in sweat, skins sebum and acidic pH, HCl acid in stomach, digested juices, vagina has acidic pH, saliva contains antimicrobials and microbial flora.
Physical anatomical barriers
Skin, thick strong and waterproof, rapid repair of damaged cells, gastric acids skin acid, vaginal tract, nasal hair and escalator traps particles, mucus, sneezing and coughing forces microbes out.
A healthy immune system is responsible for:
MHC (major histocompatabilty complex). Survellince, recognition, and destruction.
Blood, Lymph, RES (reticulo endothelial system), ECF (extra cellular fluid), and GALT (gut assoc lymphatic tissue)
How does phagocyte know self from non self?
MHC (major histocompatabilty complex)
BEN and monocytes are non-specific. Some are fixed to the lungs, and liver. Most likely attached to organ tissue where secretion occurs.
Neutrophils and some basophils
Macrophages and dendritic cells
The lymphatic system
Returns extracellular fluid to the circulatory system, involved with the inflammatory response, survelliance, recognition and protection against foreign material.
gut associated lymphatic tissue
reticular endothelial system
Differential WBC count
Normal count per mm or ml, erythrocytes 4.8-5.4 million and leukocytes 5000-9000 cells.
20-35%, B and T cells involved in specific immunity
Macrophage and dentritic cells. 3-7% phagocytes.
1-3%, destroy eukaryotic pathogens.
mast cells, .5%. release potent chemical mediators.
lymph-plasma like liquid. Blood components move out of blood vessels into extracellular spaces. WAter, dissolved salts, 2-5% proteins. Transports WBC's, fats, cellular debris and pathogens.
Small encapsulated, bean shaped organs stationed along lymphatic channels and large blood vessels of the thoracic and abdominal cavities.
Phagocytes and their activities
Cell eating, N and M. Purpose: to survey, to eliminate, and to extract info. Pus =M. Secrete cytokines (inflammation and systemic responses (ex-fever).
Pathogens that live and survive in phagocytes
TB, listeriosis. They use our defense system to infect.
Phases of phagocytosis
Chemotaxis, adhesion, ingestion, digestion, and excretion.
calor (heat), rubor (red), tumor (swelling), and dolor (pain).
migration in response to chemicals produced at the site of injury or infection.
Injured cells release cytokines:
interferons, interleukins, histamine, serotonin, bradykinins, and prostaglandins
Increased blood vessel
seals the wounds.
The wound response
Diapedesis (slip through), migration of cells out of blood vessels into the tissues.
Pus formation, microbe containment! tumor (swelling from edema, pus) calor (temp increases) and dolar.
Why are Gonnarrhea, menigitis, streps and staphs pyogenic?
Because they attracts thousands of neutrophils.
Cell division and scar tissue
Nonspecific fever response purpose?
Normal body temp (97-99.5) set by the hypothalamus. Advantages, increases temp to above pathogen optimal growth range. May inactivate pathogen heat-labile proteins. Stimulates host immune response and forces host to rest so body can fight.
2nd line of defense. Small protein produced by animal cells. Heat and pH resistant. Species specific, not pathogen specific. Antiviral, anticancer compounds. Mode of action is interference.
The complement system
26 plasma proteins (c1-c9) Works in a cascade. Alternate pathways: surface chemicals. Key proteins=C3B. Functions lise/destroy pathogens (ex-bacteria, enveloped viruses) stimulate phagocysis and regulates inflammation.
Natural killer cells (lymphocytes)
Cell-mediated but non--sepecific controlled by cytokines. Nk cells target cancer and virally infected cells that have markers. Release cytotoxins to kill cells.
enhances phagocytosis by coating protective capsule, tough cell walls (protein, wax); allowing grip of phagocytosis.
of microbes, bacteria, and enveloped viruses. membrane attack complex (MAC) forms plasma membrane channel, cell contents are lost (compliment fixation test).
by stimulating chemotaxis of phagocytes and other immune responses.