BIO 326R 1st Edition Lecture 32 Outline of Last Lecture I. Floraa. Normalb. Residentc. TransientII. Relationshipsa. Mutalismb. Commensalismc. ParasitismIII. BenefitsIV. Impaired DefenseV. Opportunistic InfectionVI. Flora Typesa. Skinb. Eyec. Orald. Repiratory Tracte. GI Tractf. Urinary Tractg. Genital (female)VII. Sterile AreasOutline of Current Lecture I. Immunitya. Innateb. Characteristicsc. Typesi. Anatomical barrier1. skin2. mucous membranesd. physiological factors that prevent colonizationCurrent LectureImmunity- innate immunity= general ability of a host to resist infectionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o first line of defenseo fast response—within minutes many pathogens are destroyed- Characteristicso Responses are broad spectrum Nonspecifico No memory or protective immunityo Limited repertoire of molecules- Types of innate responseso Anatomicalo Biochemicalo Mechanical- Anatomical barriero Skin—physical barrier, low pH (~5-6) 17-20 square feet (~2 square meters) ~15% total body weighto Layers Epidermis—first outer layer- Epidermal cells, keratin- Completely renewed every 15-30 days (~7 million skin cells/minute, 40 pounds in your life)- Tightly packed layer—waterproof- Most bacteria can’t penetrate Dermis—below epidermis, thicker, quite antimicrobial- Sebaceous glands, with hair follicles- pH ~3-5- lymphocyteso mucous membranes GI tract, respiratory tract, urogenital tract Cystic fibrosis—very prone to infection, dry mucous membranes Lots of proteins with antimicrobial activity- Lysozyme= in tears, breaks down peptidoglycan (kills gram +)- Lactoferrin= iron binding protein- Lactoperioxidase= causes oxidative stress, superoxide radicals- Lymphocytes- Physiological factors that prevent colonizationo pH= depends on location, stomach (~2), skin (~5)o microbiotao temperature (37 degrees C, 98.6 degrees F) elevated body temperature (fever)fights colonization because many bacteria do not grow at these temperatureso oxygen levels are low in many
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