BIOL 1002 Chapter : Chapter 36 Our Defenses Against Disease
Document Summary
Our defenses against disease chapter 36: most microbes are bacteria, viruses, fungi, or protozoans. Some cause disease, these are pathogens (aka germs or bugs"). The body has 3 lines of defense against microbial attack. (fig. 36-1: external barriers, non-specific internal defenses (innate immune response) Immune response directed against specific microbes(adaptive immune response: 1. External barriers are the first line of defense and are represented by the skin and mucous membranes. The intact skin is a physical barrier to microbial entry and an inhospitable enviornment for microbial growth. Sweat and sebaceous glands secrete acids and natural antibiotics like lactic acid. Mucous membranes of the respiratory and digestive tracts are well-defended. The mucus secretions have antibacterial enzymes like lysozyme. Mucous physical traps microbes entering through nose or mouth (f. 36-2) Membrane cilia sweep up mucous and microbes and they are coughed or sneezed out of the body. If microbes are swallowed stomach acid and protein digesting enzymes destroy them: 2.
