Innate immunity Flashcards
chemical barriers
secretions, tears and saliva have lysozome to break down peptiglycan. Crevicolar fluid for mouth, secretion of genitalia area, low pH of stomach
mechanical barriers
skin- mucous membrane prevents infections. Lines respiratory tract, prevents binding of pathogens to host cells.
CILIATED escalator pushes microbes toward throat to cough
biological barriers
normal flora- symbiotic, maintains health by competing with pathogens for space and nutrients.
Includes:
- strep. salvaris
- lactobacillus in stomach
neutrophils
most abundant, short lived, first to arrive at sight of injury of an infection, dominate phagocytosis, have granules
macrophages
professional Antigen presenting cells (APC), has monocytes for circulation and macrophages for tissue. It eats pathogens and damaged cells. THINK Vacumn
dendritic cells
professional APC- peptide to lymphocyte to kick start adaptive system, phagocytic cells, activation of adaptive immunity
mast cells
IgE receptor, allergies, release histamine. Most in submucosal tissue
esophil
parasitic infection defense, secrete cytolytic enzyme when contacted with pathogens
basophils
in blood, similar to mast cell, release histamine
NK cells
no memory, 1st line of defense against tumours and cancerous cells, targets and destroys by releasing cytolytic granules. DISTINGUISH BETWEEN SELF and NON SELF
lytic vs. Secretory granules
lytic- has digestive enzymes to breakdown pathogens
secretory- kill pathogens that are too big to eat (parasite), contain chemical messengers that attract other immune cells
sequence of events for tissue infection
margination- neutrophils stick to blood vessel wall
diapedesis- squeeze out gaps in cells in tissue to track down intruder
chemotaxis-movement of phagocytes toward chemical gradient to set up site of infection
phagocytosis- engulfing of pathogen
edema
cell release histamine, cause blood vessels to dilate, more permeability of blood vessels- so more leaky and cause swelling, fluid moves from blood to damaged area
exudate vs. transudate inflammation
exudate- protein rich fluid which ooze into tissue or on surface
transudate- protein poor fluid ( PUS) due to systemic factor
acute vs. chronic inflammation
acute- shorter, neutrophils are defining cells, chemotaxis directly ingest and digest pathogens such as TLR and PAMPs that target directly pathogens.
chronic- longer, more likely to develop specific recognition of pathogen, mainly mononuclear cell infiltrate, granuloma, results in peripheral tissue damage.
