MMSC 438 EXAM II

Upper respiratory tract -sinus, nasal cavity, pharynx, epiglottis and larynx -normal microbiota reside here Lower respiratory tract -trachea, lungs (bronchi and alveoli), parenchyma and diaphragm Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:01 / 0:15 Full screen Respiratory tract defense mechanisms -URT: has normal biota that inhibit other organisms -ciliated epithelial cells: work to push MOs or pollen up out of the throat -immune response: alveolar macrophages, neutrophils, Ig and complement Bacterial pathogenic mechanisms -evasion of host defenses: avioding phagocytosis, survival inside the phagocyte (intracellularly), inactivating complement and forming a biofilm -adhesion to host respiratory cells -toxin production: Corneybacterium diphtheriae and Bordetella pertussis General considerations (transmission) -person to person: airborne droplets (coughing and sneezing) and seasonal variations (flu season) -aspiration of endogenous biota -trauma (knife bacteria) -environmental and animal reservoirs (may be location dependent) -fomites: objects or materials which are likely to carry infection (clothing and doorknobs) Norma