What effect does atherosclerosis have on blood flow through arteries?

Atherosclerosis significantly impacts blood flow through arteries primarily by increasing resistance to blood flow. This condition occurs when arteries become narrowed and hardened due to plaque buildup, which usually consists of fats, cholesterol, and other substances. The narrowing of the arteries creates increased resistance against the blood flow.

When resistance to blood flow increases, the heart must exert more force to push blood through these constricted arteries. This leads to a rise in blood pressure as the circulatory system works harder to overcome the obstruction. Thus, the correct understanding is that atherosclerosis increases resistance to blood flow, which in turn causes an increase in blood pressure. This relationship is crucial in understanding cardiovascular health, as elevated blood pressure from atherosclerosis can lead to further complications, including heart disease and stroke.

The other options suggest either a decrease in resistance or a misunderstanding of how blood pressure responds to changes in resistance, which do not accurately reflect the physiological changes that occur with atherosclerosis.