Pulmonary arteries are the blood vessels that move blood from the right side of the heart to the lungs where blood receives oxygen. The pressure in these arteries is lower than the systemic blood pressure(the pressure of blood which is measured routinely and comes from the left side of the heart).When pressure in the pulmonary arteries rises too much, the condition is known as pulmonary hypertension. It is usually associated with an underlying disease.
Attribution: Avallain