Mucous Membrane - The moist linings of body passages and internal cavities involved with absorption and secretion of substances.⏎
Immune System - The system of biological structures and processes that protects the body from foreign substances, including pathogens.⏎
Host - An organism that harbors a parasite or another organism where there is a symbiotic relationship between the two organisms. In some cases, the relationship is commensal, or mutually beneficial, but in the case of a parasite and host, the host may be hurt by the parasite's presence.⏎
Mortality - The number of deaths in a given time or place.⏎
Germ Theory - A theory in medicine stating that microorganisms are the causative agents of infectious, contagious diseases.⏎