Final answer:
The right ventricle generates the pressure necessary to move blood through the pulmonary vasculature, part of the pulmonary circuit involving the heart and lungs.
Step-by-step explanation:
Blood is moved through the pulmonary vasculature by pressure generated within the right ventricle of the heart. When blood returns from the systemic circuit, it enters the right atrium via the superior and inferior venae cavae and the coronary sinus. It is then low in oxygen and high in carbon dioxide, reflecting its state after delivering oxygen to the tissues and picking up carbon dioxide to be expelled. The right atrium transfers blood to the right ventricle, which pumps it into the pulmonary trunk. This then bifurcates into the right and left pulmonary arteries, leading to the pulmonary capillaries where gas exchange occurs. Finally, oxygenated blood returns to the left atrium through the pulmonary veins, completing the pulmonary circulation.