BSCI 202 Study Guide - Midterm Guide: Natural Killer Cell, Adaptive Immune System, Defensin

139 views4 pages

Document Summary

Innate (nonspecific) defense system and the adaptive (specific) defense system. Innate defense system has two lines of defense: First - external body membranes (skin and mucosae) Second - antimicrobial proteins, phagocytes, and other cells>>inhibit spread of invaders and causes inflammation. It"s the third line of defense attacks particular foreign substances. It also takes longer to react than innate system. Surface barriers that ward off invading pathogens>these barriers applies to the skin, mucous membranes, and secretions: act as physical barrier to most microorganisms, acid secretion, enzymes>>lysozymes of saliva, respiratory mucous, and lacrimal fluid, antimicrobial secretions>>applies to defensins. If the surface barriers are breached then that means the second line of defense has to protect the other tissues. Internal defenses: nk cells, antibacterial proteins, phagocytes, fever, and inflammatory response. Neutrophils = most abundant but die fighting. Macrophages = develop from monocytes chief phagocytic cells robust cells. Free macrophages wander through tissue spaces while fixed macrophages are permanent residents of some organs.