The blood in the subclavian vein of the chest had a P1 of 15 mm Hg. For the blood to flow back to the heart, the P2 in the superior vena cava:

Question

Quizplus · Accepted Answer

Blood flow occurs from high pressure to low pressure. In this case, the pressure in the subclavian vein is 15 mm Hg and in order for the blood to flow back to the heart, the pressure in the superior vena cava (which carries blood from the upper half of the body to the heart) must be lower than 15 mm Hg. Therefore, the only possible option is choice C, where P2 would have to be less than 15 for blood to flow back to the heart.

The Blood in the Subclavian Vein of the Chest Had