HSCI 100 Chapter Notes -Adaptive Immune System, Natural Killer Cell, Complement System

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Nienke Van Houten

Document Summary

First line of defense nonspecific physical & chemical surface barriers. Keep foreign organisms/molecules out of body in first place. Second line of defense non specific defensive cells & proteins, inflammation, fever. Attack any foreign organism/molecule/cancer cell inside body. 2nd line of defense = internal cellular & chemical defenses are activated: engulf pathogens, damaged tissue, dead cells via phagocytosis, e. g. neutrophils arrive @ site of attack and begins consume of pathogens. Monocytes leave vessels of circulatory, enters tissue fluids, become macrophages. Eosinophils attack pathogens too large for phagocytosis (parasitic worms: natural killer cells (nk) Prime target = cancerous cells, cells infected with virus. Creates pores in abnormal cell so that it leaks away. Protect cells that are not yet infected (all strains: complement system assists other defensive mechanisms. Group of 20 proteins whose activities enhance body"s defense mechanisms. Directly punches holes in target cell"s membrane: cell cannot maintain constant internal enviro.