Answer
Thoracic pump
Work Step by Step
The role of breathing in venous return is called the thoracic pump.
When you inhale, your thoracic cavity expands and its internal pressure drops. At the same time, the downward movement of the diaphragm increases the pressure in your abdominal cavity. The inferior vena cava passes through both of these cavities. So, as you inhale, abdominal pressure increases on the IVC while thoracic pressure on the IVC decreases, squeezing blood upwards towards the heart. This mechanism is called the thoracic pump.
