Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

Which component plays a key role in maintaining blood pressure?

1. Platelets

2. Arteries

3. Veins

4. Capillaries

The correct answer is: Arteries

Arteries play a crucial role in maintaining blood pressure because they are the blood vessels that carry oxygenated blood away from the heart to the tissues of the body. The structural characteristics of arteries, such as their thick, muscular walls, allow them to withstand and regulate the high pressure generated by the heart's pumping action. This pressure is essential for ensuring that blood is distributed effectively to various organs and tissues. The ability of arteries to constrict and dilate (change their diameter) also directly influences blood pressure. When arteries constrict, blood pressure rises because the same volume of blood is forced through a narrower space. Conversely, when they dilate, blood pressure decreases as the blood flows through a wider space. This regulation of blood pressure by arterial response is vital for maintaining homeostasis and ensuring that tissues receive adequate blood flow according to their metabolic needs. In contrast, while platelets are essential for blood clotting, veins are primarily responsible for returning deoxygenated blood back to the heart, and capillaries facilitate the exchange of gases, nutrients, and waste products between blood and tissues. These functions are important but do not have the same direct impact on the maintenance of blood pressure as the role played by arteries.