The part of the circulation involved with pumping blood to and from the lungs is the

A) systemic circuit.
B) internal respiration circuit.
C) microcirculation circuit.
D) pulmonary circuit.
E) ECG circuit.

The pulmonary circuit is responsible for pumping blood to and from the lungs for gas exchange. The systemic circuit, on the other hand, is responsible for pumping oxygenated blood to the rest of the body. The internal respiration circuit and microcirculation circuit are not specific parts of the circulation system. The ECG circuit is not a part of the circulation system at all, but rather a test used to assess the heart's electrical activity.