NSG 3336 Lecture Notes - Lecture 24: Respiratory Tract, Respiratory Tract Infection, Bactericide
Document Summary
First line defense lies in urt > nasal cavities, pharynx, and larynx. Nares and nasal cavities are equipped with hairs and a mucous layer that lter out and trap macroparticulates. Also lined with epithelial tissues and blood vessels that lter and warm inspired air > secretes antimicrobial peptides that exert bactericidal effect on a variety of pathogens. Larynx houses the epiglottis that provides mechanical protection of the airways. Preventing aspiration, the epiglottis closes while food or uids are swallowed. Colonization = collection of number of bacteria small enough not to cause infection to maintain healthy respiratory status by competing with pathogens for attachment sites in the respiratory mucous lining and producing bactericidal substances that destroy harmful microorganisms. Staphylococcus, streptococcus, spirochetes, mycobacteria, pseudomonas, proteus, and enterococcus. Trachea marks the beginning of the lower respiratory tract. Ciliated cells along with mucous secreting cells protect lower respiratory tract via the mucociliary escalator.
