Secreted by sebaceous oil glands helps keep skin

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secreted by sebaceous (oil) glands Helps keep skin pliable and less likely to break or tear Lowers pH of skin to a level inhibitory to many bacteria First Line of Defense Images: Cartoon of castle being defended, Source unknown; Hair follicle , Wiki From the Virtual Microbiology Classroom on ScienceProfOnline.com
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________ __________ Line all body cavities open to the outside environment. Unlike surface epidermal cells, epithelial cells are living. Epithelial cells packed tightly to prevent entry of pathogens, but often only one cell layer thick, so pathogens sometimes breech the barrier. Continual shedding of cells carries attached microorganisms away Besides producing mucus, mucous membranes also produce lysozyme and other antimicrobial peptides . OMG U R Nasty > Every day you swallow and digest about 1 liter of mucus. Images: Photo mucous membrane, Source unknown, Drawing of mucous membrane , Gray’s Anatomy First Line of Defense From the Virtual Microbiology Classroom on ScienceProfOnline.com
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_______ Line of Defense - ____________ Operates when pathogens penetrate skin or mucous membranes. Cells, antimicrobial chemicals, and processes, but no physical barriers. Many of these components are contained or originate in the blood. Second Line of Defense Images: Neutrophil bacterial phagocytosis , Uwe Thormann; Ingrown toenail inflammation , Wiki From the Virtual Microbiology Classroom on ScienceProfOnline.com
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Formed Elements Three types of formed elements ___________ - red blood cell, carry oxygen & carbon dioxide in the blood. __________ - involved in blood clotting (also called thrombocytes). ____________ - white blood cells ; involved in defending the body against invaders. 2 groups Granulocytes Agranulocytes Scanning electron micrograph of formed elements RBC (left) platelet (center) leukocyte (right) Image: Formed elements , NCI-Frederick Second Line of Defense From the Virtual Microbiology Classroom on ScienceProfOnline.com
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Leukocytes > _____________ Category of white blood cells characterized by presence of granules in their cytoplasm. 3 types: ____________ - Most abundant white blood cell. Predominant cells in pus, accounts for its whitish appearance. Respond quickly following tissue injury. Hallmark of acute inflammation. ___________ - Least common granulocyte. When activated, release histamine and other inflammatory chemicals. ___________ - Main effecter cells in allergic responses & asthma. Also fight helminth (worm) colonization. Neutrophils and eosinophils can phagocytize pathogens. Second Line of Defense Image: Neutrophil engulfing Bacillus anthracis , Volker Brinkmann, Photos of granulocytes , Wiki; Drawing of granulocytes , US Gov From the Virtual Microbiology Classroom on ScienceProfOnline.com
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Leukocytes > _____________ 2 types: ______________ - most involved in specific immunity (3 rd line of immune defense), ______________ - leave the blood and mature into macrophages (phagocytic cells of the second line of defense).
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