Final answer:
The 'exciting cause of a disease' is the immediate trigger that initiates the development of a disease in someone who may be susceptible. It can refer to a pathogen in infectious diseases, or an environmental or lifestyle factor in noninfectious diseases like cancer.
Step-by-step explanation:
The term "exciting cause of a disease" refers to the specific factor that triggers the onset of a disease in an individual who may already be predisposed to the condition. In the context of an infectious disease, this exciting cause would typically be the pathogen responsible, such as bacteria or viruses, that initiates the disease process.
For example, the Epstein-Barr virus may serve as the exciting cause for infectious mononucleosis. When considering noninfectious diseases like cancer, the exciting cause might be an environmental factor like exposure to carcinogens or significant lifestyle choices that bring about the abnormal cell growth characteristic of the disease.