Innate Immunity - Non-specific Immunity Flashcards
resistance
the capacity of bacteria to withstand the effects of a harmful chemical agent
Innate resistance
the first line of response of the body’s immune system to aharmful foreign substance
* Physical & Genetic: intact skin, mucus membranes
* Chemical: secretions, enzymes, pH
Non-specific resistance
the second line of defense that destroys invaders in a generalized way without targeting specific individuals
* Phagocytic WBC, inflammation, fever, complement, interferon
Specific Resistance
aka acquired immunity. Third line of defense system which relies on antigens, which are specific substances found in foreign chemicals
* B&T lymphocytes, antibodies
Susceptibility
the state of being predisposed to, or sensitive to, developing a certain disease
Physical/Anatomical Barriers
- Skin: thick, strong, and waterproof barrier
- Nasal hair, cilia, and wax trap particles to prevent them reaching portals of entry
- Mucous coating of cells stops attachment and entry of bacteria
- Flushing effect: sweating, salivaa, tears, mucus, urine, defecation, vomitting
- Blinking (eyelid and lashes), coughing, sneezing, and ciliated escalator (mucus/cilia) forces microbes out
- Blood clots seal off portals of entry at injury sites
- Damaged cells undergo rapid recovery
Chemical Defenses
- Lysosomes in tears, sweat, and mucus digest peptidoglycans damaging bacteria
- Saliva contains antimicrobials
- Sweat pH & high [electrolyte] - antimicrobial
- Skin is coated in oily sebum - antimicrobial
- Gastric acid (HCl) is secreted in stomach
- Digestive juices (enzymes and bile) in GI
- Vagina has acidic pH in GU - Microbiota
- Microbiota prevents opportunistic overgrowth and are antagonistic to some pathogens difficult for pathogens to colonize and penetrate
Responsibilites of the Immune System
- Surveilence
- Recognition
- Destruction
What does the Immune System consist of?
- Blood
- Lymph
- Reticuloendothelial System (RES)
- Extracellular Fluid (ECF)
- Gut-Associated Lymphatic Tissue (GALT)
Major Histocompatibility Complex (MHC)
- Closely linked cluster of genes that program cell surface glycoprotein markers that control immune interactions between cells and are involved in immune interactions between cells and some hypersensitivites, transfusion reactions, and graft rejections.
- tldr; how similar you are to your neighbor
- found on every cell-surface except RBC’s (which is why we are able to donate blood)
Pathogen Recognition Receptors
- receptors on host cells that recognize pathogens via surveilance and phagocytes recognize the Pathogen Associated Molecular Patterns (PAMPs)
- Includes Toll-like Receptors (TLRs)
- Phagocytosis occurs, cytokines are released and innate immune response is triggered
Toll-Like Receptors
small surface receptors on phagocytes that are specialized to bind and react to pathogens
Pathogen Associated Molecular Pattern
molecules on the surfaces of pathogenic microbes that are recognized by phagocytes and trigger immune responses against the microbes
Leukocytes
- Aka phagocytes
- Granulocytes - neutrophils (do most of the eating/destructing)
- Monocytes - macrophages (+ dendritic cells)
if triggered, monocytes turn into macrophages
Differential Blood Count
measures the percentage of each type of WBC that you have in your body (normal erythrocytic count is 4.8 - 5.4 million, leukocytic 5,000-9,000 cells per mL
Cell Makeup
- Neutrophils: 55-90% Granulocytes; Phagocytes
- Lymphocytes: 20-35% - B&T cells involved in specific immunity
- Monocytes (macrophages/dendritic cells): 3-7% phagocytes
- Eosinophils: 1-3%; destroys eukaryotic pathogens
- Basophils, mast cells: 0.5% release potent chemical mediators
