BIOL 1080 Study Guide - Midterm Guide: Insulin Resistance, Adipose Tissue, Adverse Drug Reaction
Document Summary
First line of defense external physical barriers. Skin provides physical barrier to the entrance of microbes: acidic ph discourages growth of organisms. Large intestine normal bacterial inhabitants keep invaders in check. Saliva washes microbes from teeth and mucous membranes of the mouth. Respiratory tract mucus traps organisms and cilia sweep away trapped organisms. Bladder urine washed microbes from urethra. Second line of defense identifies foreign (non-self) (cid:373)atter, (cid:271)ut is(cid:374)"t spe(cid:272)ifi(cid:272) a(cid:374)d does(cid:374)"t de(cid:448)elop a (cid:373)e(cid:373)ory. Internal resident cells engulf invading organisms: phagocytic cells. Proteins slow spread of viruses in body, stimulates histamine release, and promotes phagocytosis. Inflammation brings in defensive cells and speeds healing. Fever slows growth of bacteria, speeds up body defenses. Phagocytes: neutrophils: first on the scene, consuming bacteria, macrophages: consume almost anything. Non-phagocytes: (target pathogens/organisms too large for phagocytosis: eosinophils: discharge enzymes that digest target, natural killer cells: constantly circulate and patrol for non-self, prime targets are cancer cells, release perforin and proteases to destroy cells.
