Final answer:
Coronary artery spasms can be triggered by physical exertion, emotional stress, and exposure to cold. During exercise, partially blocked arteries may be unable to pump sufficient blood, leading to spasms. Severe stress can also cause spasms in the coronary arteries.
Step-by-step explanation:
Coronary artery spasms can be precipitated by physical exertion, emotional stress, and exposure to cold. When a partially occluded artery is unable to pump enough blood during exercise, it can lead to spasms in the smooth muscle of the artery walls. Severe stress can also induce spasms in the coronary arteries.