Pulmonary circulation is the flow of blood from the right ventricle through the pulmonary artery to the lungs, where carbon dioxide (CO2) is exchanged for oxygen (O2), and back through the pulmonary vein to the left atrium. The pulmonary vasculature includes the arteries from the main pulmonary to the precapillary arterioles, the capillaries, and the vein from the capillary to the left atrium. – Wikipedia.
The pulmonary circulation, once referred to as the lesser circulation, is now a circulatory system that medical and research professionals (as well as patients) can no longer ignore. Based on the World Health Organization's (WHO) annual report in 2010, pulmonary vascular disease (e.g., pulmonary hypertension, pulmonary embolism) affects more than two million people in the world. The survival from idiopathic pulmonary arterial hypertension (IPAH), a rare form of pulmonary hypertension that predominantly affects younger women, is similar to cancer and is worse than many ischemic cardiovascular diseases.