BIOL 1002 Chapter : Imune System Ch. 36
Document Summary
97% females & 92% males say they wash their hands. 50% high school students say & 33% wash. Three lines of defense against microbial attack: external barriers keep the pathogens out (skin & mucus membranes, skin, physical barrier to microbial entry. Inhospitable environment for growth; dry dead cells at surface. Sweat/sebaceous glands secreting acids & natural antibiotics like lactic acid: mucous membranes of respiratory & digestive tracts well defined. Secretions have antibacterial enzymes. (ex: dirt caught in mucus moved by cilia). The cell dies and the cell is broken down and reused. They also recognize abnormalities on the cell): inflammatory response: caused by large-scale microbial invasion through wound. out the wound. (red, swollen, warm, histamine is released when cell damage is detected, other chemicals from damaged cells attract phagocytic. Histamine increases the amount of blood flow to wash . Wbc"s that engulf bacteria, dirt, and tissue debris: blood clotting walls off" wounded area.
