Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Diseases of the cardiovascular system are common and may be life threatening. Examples include atherosclerosis and coronary heart disease. A healthy lifestyle can reduce the risk of such diseases developing. This includes avoiding smoking, getting regular physical activity, and maintaining a healthy percent of body fat. Answer: cardiovascular system
A:
Atherosclerosis and coronary heart disease are examples of what type of body system disease?