Pulmonary circulation transports blood through the alveoli for gas exchange. In this circulation the blood that comes from the veins initially has low oxygenation, and then leaves the right ventricle of the heart through the pulmonary artery, enters the lungs and returns to the heart with arterial and oxygenated blood
The bronchial circulation is well oxygenated and provides oxygen to the lungs. The structures to which this oxygen contributes in lungs are those that do not participate in a gas exchange.
