Final answer:
Elastic arteries are essential for pulsating blood flow because their walls stretch and recoil with each heartbeat, smoothing out the pressure fluctuations and enabling a steady flow of blood. Arteries' elasticity lowers the risk of high blood pressure and reduces the heart's workload.
Step-by-step explanation:
The elastic properties of arteries are crucial for maintaining blood flow. Blood flow in arteries is pulsating, not continuous, due to the rhythmic pumping of the heart. When the heart contracts and pumps blood, the arterial walls stretch because of the increased pressure. This stretching is possible because of the elastic fibers in the arterial walls. Then, when the heart relaxes, the pressure in the arteries falls, and the elastic recoil of the arterial walls helps maintain the blood flow until the next heartbeat. This elasticity is vital for smoothing out the pressure fluctuations and providing a more steady flow of blood to tissues and organs.
If arteries were not elastic and were instead rigid, the pulsating flow would be more extreme, causing potentially damaging high blood pressure and requiring the heart to work much harder to circulate blood. This would lead to increased wear and tear on the cardiovascular system. Therefore, option b) 'Pulsating blood flow requires elastic arteries' is correct as it explains the physiological need for elasticity in arterial walls to accommodate the pulsating nature of blood flow from the heart.