A nurse is teaching a class about pulmonary circulation. The nurse should include that blood flows from the heart to the lungs starting from which of the following locations?

Choice A rationale The pulmonary circulation begins when deoxygenated blood, returning from the systemic circulation, enters the right atrium and then passes into the right ventricle. The right ventricle is the chamber that contracts forcefully to push this deoxygenated blood through the pulmonary semilunar valve into the main pulmonary artery, initiating the flow toward the lungs for gas exchange. Choice B rationale The left atrium receives oxygenated blood from the lungs via the pulmonary veins and then pumps it into the left ventricle. This chamber is part of the systemic circulation loop, receiving the final product of pulmonary circulation, and is not the starting point for the flow of blood from the heart to the lungs. Choice C rationale The pulmonary artery is the vessel that transports deoxygenated blood from the right ventricle to the lungs. While it carries the blood to the lungs, it is the vessel following the starting chamber, which is the right ventricle, the contracting muscle that generates the initial pressure for the blood's journey. Choice D rationale The pulmonary veins carry oxygenated blood from the lungs back to the left atrium of the heart. These vessels are the termination point of the pulmonary circulation loop, after gas exchange has occurred in the capillaries of the lungs, and therefore they are not involved in the initial outflow to the lungs. —.