What are the bodys three lines of defense against pathogens. In the first line of defense the surfaces of the skin breathing passages mouth and stomach function as barriers to pathogens. The Effects Of Biological Self Restore As An Immune System Booster On Nonspecific Resistance Of The Organ Lymphatic System Study Immune System Lymphatic System 312 The human body has 3 lines of defense against. . Ch 31- Pathogens 30 Terms. The first line of defence is your innate. Up to 24 cash back Third line of defense. The third line of defense in the body is the specific immune system a system that defends against pathogens. These barriers act to trap and kill most pathogens and include the surfaces of the skin breathing passages mouth eye and. Barriers inflammatory response and immune response. Start studying Chp 21 identify the bodys three lines of defense against pathogens. In the first line of defense the body has