The circulatory system, which is connected to the lungs via arteries and veins, forms the circulatory system's pathway. Pulmonary circulation is the process of flow of blood from the heart to the lungs and then back to the heart. The heart receives regular oxygenated blood, whereas the pulmonary artery transports deoxygenated blood from the right ventricle to the lungs. It is the blood's path through arteries from the aorta, which rises from the heart to the right atrium.