Study GuideMicrobiology–Nonspecific Body Defense1. Nonspecific Mechanisms of DefenseThe human body has severalnonspecific defense mechanismsthat protect against many differentmicroorganisms. These defenses are callednonspecificbecause they act againstall types ofpathogens, not just one particular organism.Their main goals are:•Toprevent microorganisms from enteringthe body•Todestroy pathogensif they reach deeper tissues1.1Mechanical Barriers–The First Line of DefenseMechanical barriers are part of the body’snormal structure and function. They act as thefirst lineof defenseat portals of entry.SkinTheskinis one of the strongest mechanical barriers.•The outer layer consists of tightly packed cells•These cells are filled withkeratin, an insoluble protective protein•This thick layer iswaterproofandresistant to infection•When intact, skin is usuallyimpenetrable to pathogensMucous MembranesMucous membranes line the:•Respiratory tract•Digestive tract•Urinary tractPreview Mode
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