IMM250H1 Study Guide - Quiz Guide: Weak Interaction, Hospital-Acquired Infection, Vaccinia
Document Summary
Mucosa body surfaces potentially exposed to microbes. Physical barriers: anatomical barriers, mechanical factors, chemical factors, biological factors. Blood-borne factors: humoral components, complement, coagulation system, cytokines. Innate cells defenders : cellular components, neutrophils, epithelial cells, monocytes and macrophages, nk cells, eosinophils. Removal of particles including microorganisms by rapid passage of air over cilia in nasopharynx. High turnover rates, allows skin cells to slough off at high rates - protective mechanism because if pathogen stuck on skin it will be sloughed off in a few days. Mechanical factors: cell type: squamous epithelium, physical barrier, desquamation. Prevents attachment: component: hcl (parietal cells in stomach) Kill bacteria: component: tears and saliva, lysozyme and phospholipase a. Kill bacteria by dissolving cell wall: component: antimicrobial peptides, defensins (respiratory & gi tract, antimicrobial. Antimicrobial molecules that can poke holes in bacteria and kill them: component: surfactants (lung, opsonin (enhances uptake by phagocytes) Coat bacteria particles and are more easily recognized by innate system.
