Title: Pulmonary circulation
Content:  Deoxygenated blood leaves the heart, goes to the lungs, and then re-enters the heart; deoxygenated blood leaves through the right ventricle through the pulmonary artery. From the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve) into the right ventricle. Blood is then pumped from the right ventricle through the pulmonary valve and into the main pulmonary artery.
Title: Pulmonary circulation
Content:  The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left part of the heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. From the left ventricle, the blood passes through the aortic valve to the aorta. The blood is then distributed to the body through the systemic circulation before returning again to the pulmonary circulation.
Title: Pulmonary artery
Content:  The pulmonary arteries are blood vessels that carry blood from the right side of the heart through to the capillaries of the lungs. The blood that is carried is, unlike other arteries, without oxygen ("deoxygenated"). The main pulmonary arteries emerge from the right side of the heart, and these split into smaller arteries that progressively divide and become smaller until they become arterioles and eventually capillaries.
Title: Pulmonary artery
Content:  The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. The blood here passes through capillaries adjacent to alveoli and becomes oxygenated as part of the process of respiration. In contrast to the pulmonary arteries, the bronchial arteries supply nutrition to the lungs themselves.
Title: Pulmonary circulation
Content:  The pulmonary arteries carry deoxygenated blood to the lungs, where carbon dioxide is released and oxygen is picked up during respiration. Arteries are further divided into very fine capillaries which are extremely thin-walled. The pulmonary veins return oxygenated blood to the left atrium of the heart.
Title: Pulmonary artery
Content:  A pulmonary artery is an artery in the pulmonary circulation that carries deoxygenated blood from the right side of the heart to the lungs. The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the arterioles, which lead to the capillaries that surround the pulmonary alveoli.
Title: Pulmonary circulation
Content:  From the right ventricle, blood is pumped through the semilunar pulmonary valve into the left and right main pulmonary artery (one for each lung), which branch into smaller pulmonary arteries that spread throughout the lungs.
Title: Blood
Content:   Blood is circulated around the body through blood vessels by the pumping action of the heart. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through veins. It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again. Arterial blood carries oxygen from inhaled air to all of the cells of the body, and venous blood carries carbon dioxide, a waste product of metabolism by cells, to the lungs to be exhaled. However, one exception includes pulmonary arteries, which contain the most deoxygenated blood in the body, while the pulmonary veins contain oxygenated blood. Additional return flow may be generated by the movement of skeletal muscles, which can compress veins and push blood through the valves in veins toward the right atrium. The blood circulation was famously described by William Harvey in 1628.
Title: Circulatory system
Content:  The circulatory system of the lungs is the portion of the cardiovascular system in which oxygen-depleted blood is pumped away from the heart, via the pulmonary artery, to the lungs and returned, oxygenated, to the heart via the pulmonary vein. Oxygen-deprived blood from the superior and inferior vena cava enters the right atrium of the heart and flows through the tricuspid valve (right atrioventricular valve) into the right ventricle, from which it is then pumped through the pulmonary semilunar valve into the pulmonary artery to the lungs. Gas exchange occurs in the lungs, whereby is released from the blood, and oxygen is absorbed. The pulmonary vein returns the now oxygen-rich blood to the left atrium. A separate system known as the bronchial circulation supplies blood to the tissue of the larger airways of the lung.
Title: History of medicine
Content:  Blood enhanced with pneuma, which means wind or breath, is carried by the arteries. The path that blood take is as follows: venous blood passes through the vena cava and is moved into the right ventricle of the heart; then, the pulmonary artery takes it to the lungs. Later, the pulmonary vein then mixes air from the lungs with blood to form arterial blood, which has different observable characteristics. After leaving the liver, half of the yellow bile that is produced travels to the blood, while the other half travels to the gallbladder. Similarly, half of the black bile produced gets mixed in with blood, and the other half is used by the spleen.

Question: where does blood go when it leaves the pulmonary artery?
Answer: lungs.
The pulmonary vein.