Blood pressure in arteries is higher than blood capillary pressure.

• A. True
• B. False
• C. Not sure
• D. Both true and false

Answer: (A)

Arterial blood pressure is higher than capillary pressure because the heart generates the high pressures that propel blood into the arterial system, while capillaries operate at a much lower pressure to allow safe, efficient exchange of nutrients, gases, and wastes. In systemic arteries, pressures are around a systolic ~120 mmHg and diastolic ~80 mmHg (mean ~90–100 mmHg), but by the time blood reaches the capillaries, pressure has fallen to roughly 20–30 mmHg due to resistance in the arterioles and the enormous total cross-sectional area of the capillary network. If capillary pressures were as high as arterial pressures, capillaries could be damaged and fluid exchange would be impaired. So the statement is true.