BIO 226 Chapter 15: Bio 226 Ch. 15 Outline
7 Nov 2018
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Document Summary
Portal of entry- where pathogens can gain entrance to the human body and other hosts. Mucous membranes: respiratory tract, gi tract, genitourinary tract, and conjunctiva (eye) Preferred portal of entry for a few common diseases: Id50- virulence of a microbe; infectious dose for 50% of the test population. Ld50- potency of a toxin; lethal dose of a toxin for 50% of the test population. If an organism is highly virulent, it would have a low id50. Glycocalyx: streptococcus mutans, s. pneumoniae, klebsiella pneumoniae. Biofilms: mass of microbes adhering to a moist surface (resistant) Capsules- glycocalyx material formed around cell walls of bacteria (increases the virulence of the species) Help bacteria resist phagocytosis by white blood cells. Opa and fimbriae- bacteria use these to attach to host cells. Waxy lipid (mycolic acid)- resists digestion by phagocytes. Cytoskeleton- consist of actin protein which is used by some microbes to penetrate host cells.
