The pulmonary artery is the blood vessel in vertebrates which carries deoxygenated blood from the heart to the lungs. It receives blood from the right ventricle through the pulmonary valve. The main pulmonary artery is about 5 cm long and 3 cm in diameter. From the base of the right ventricle, it goes up to divide into two branches just below the aortic arch, with one branch traveling to each lung. The left pulmonary artery is the shorter than the right.