Which statement about hydrostatic pressure and blood flow is correct?

• A. Hydrostatic pressure is irrelevant
• B. Arterial segments experience high hydrostatic pressure driving forward flow
• C. Venous segments have higher hydrostatic pressure
• D. Hydrostatic pressure is the same in arterial and venous segments

Answer: (B)

Blood flow is driven by a pressure gradient created by the heart. After each heartbeat, arteries carry blood under high pressure, pushing it forward through the circulation. Veins, by contrast, operate at much lower pressure, so they don’t provide a strong forward-driving force. Gravity adds a hydrostatic component that can vary with body position, but the main driver of forward flow is the high arterial pressure relative to venous pressure. That’s why arterial segments have high hydrostatic pressure that pushes blood onward, while venous segments stay low. The other statements misstate the relative pressures or ignore the driving role of arterial pressure.