Which two body compartments are engaged in the two-chambered pump concept?

Which two body compartments are engaged in the two-chambered pump concept?

• A. Thoracic and abdominal cavities
• B. Left and right ventricles
• C. Lungs and stomach
• D. Brain and spinal cord

Answer: (A)

The idea here is that venous return is helped by two body compartments that act together like a pump: the thoracic cavity and the abdominal cavity. When you inhale, the diaphragm moves downward, expanding the thoracic cavity and lowering intrathoracic pressure, which draws blood toward the heart. At the same time, the abdominal cavity is compressed a bit and abdominal venous pressure rises, pushing blood from the legs and abdomen toward the central veins. This coordinated pressure change in the chest and abdomen keeps venous return steady. The other options don’t fit because the left and right ventricles are actual chambers of the heart, not external compartments that work as a pump together; the lungs and stomach are individual organs, and brain and spinal cord are nervous tissue, not paired pumping compartments. So the two engaged compartments are the thoracic and abdominal cavities.

The idea here is that venous return is helped by two body compartments that act together like a pump: the thoracic cavity and the abdominal cavity. When you inhale, the diaphragm moves downward, expanding the thoracic cavity and lowering intrathoracic pressure, which draws blood toward the heart. At the same time, the abdominal cavity is compressed a bit and abdominal venous pressure rises, pushing blood from the legs and abdomen toward the central veins. This coordinated pressure change in the chest and abdomen keeps venous return steady. The other options don’t fit because the left and right ventricles are actual chambers of the heart, not external compartments that work as a pump together; the lungs and stomach are individual organs, and brain and spinal cord are nervous tissue, not paired pumping compartments. So the two engaged compartments are the thoracic and abdominal cavities.