Immune System - The system of biological structures and processes that protects the body from foreign substances, including pathogens.⏎
Mucous Membrane - The moist linings of body passages and internal cavities involved with absorption and secretion of substances.⏎
Microbe - Sometimes referred to as a microorganism, a microbe is an organism that is microscopic and thus invisible to the naked eye. ⏎
Incubation Time - The period of time between exposure to an infectious agent and the appearance of symptoms of the infection or disease it causes.⏎
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.⏎