Which statement about arteries and veins is true?

Which statement about arteries and veins is true?

• A. Arteries carry blood away from the heart; veins carry blood toward the heart
• B. Veins carry blood away from the heart; arteries carry blood toward the heart
• C. Both always carry oxygenated blood
• D. Veins have thicker walls than arteries

Answer: (A)

Blood flows in arteries away from the heart and in veins toward the heart. This directional pattern holds true in systemic circulation: the heart pumps blood into arteries to supply the body, and then blood returns to the heart through veins. The thicker, muscular walls of arteries help them withstand the high pressure of pumped blood, while veins have thinner walls and valves to aid return flow back to the heart, assisted by muscle movement. Keep in mind that oxygen content isn’t what defines this rule—pulmonary arteries carry blood to the lungs (deoxygenated) and pulmonary veins bring oxygenated blood back to the heart—yet the overall direction remains the same.

Blood flows in arteries away from the heart and in veins toward the heart. This directional pattern holds true in systemic circulation: the heart pumps blood into arteries to supply the body, and then blood returns to the heart through veins. The thicker, muscular walls of arteries help them withstand the high pressure of pumped blood, while veins have thinner walls and valves to aid return flow back to the heart, assisted by muscle movement. Keep in mind that oxygen content isn’t what defines this rule—pulmonary arteries carry blood to the lungs (deoxygenated) and pulmonary veins bring oxygenated blood back to the heart—yet the overall direction remains the same.