Blood flows from which pressure to which pressure?

• A. Low to high
• B. Equal
• C. High to low
• D. Variable

Answer: (C)

Blood moves down a pressure gradient: from areas of higher pressure to areas of lower pressure. This pressure difference is what drives circulation, carrying blood from the high‑pressure arterial system, through capillaries, to the lower‑pressure venous system. In normal function, arterial pressures exceed venous pressures, so net flow is from high to low pressure. If pressures were equal, there would be no net flow, and moving from low to high pressure would require external work, which isn’t how circulation is driven. Therefore, the direction of flow is from high to low pressure.