BIOL 1011 Lecture Notes - Lecture 4: Disulfide, Natural Killer Cell, Antigen
Document Summary
Enhanced by previous exposure (have to be exposed to a pathogen in order to become immune to it) Epithilelial tissue covers the body(skin) to prevent entrance of pathogens. Internal mucus membranes are very vulnerable so they secrete mucus to enhance defence. Lysozymes in tears, saliva, and mucus breakdown cell membranes of pathogens. Stomach acid kills most bacteria before entering the digestive system. Do not engulf, secret chemicals to break down molecules or cells. Cells infected with the virus secrete interferons to nearby uninfected cells, whose response is to secret chemicals that interfere with viral infection. If skin is damaged by splinter, the splinter pathogens penetrate the skin and bacteria enters, the mast cell holds histomines, and macrophage cells engulf pathogens and secrete chemical signals. Histomine will act at the blood vessel wall to dilate the blood flow in the vessel, making the membrane leaky, bringing white blood cells that attack and engulf the pathogens underneath the skin.
