The main pulmonary artery is responsible for transporting oxygen-depleted blood away from the heart and back toward the lungs. The main artery splits into the left pulmonary artery and the right pulmonary artery, each of which directs the blood to the corresponding lung. Along with the umbilical arteries, these are the sole arteries in the body that transport oxygen-depleted blood. The umbilical arteries are located in the uterus. The pulmonary artery, or pulmonary trunk, originates from the bottom of the right ventricle of the heart. The artery is wide and short, measuring 1.2 inches wide and 2 inches long. When blood pressure increases in the right or left pulmonary artery or the main pulmonary artery, this is referred to as pulmonary hypertension and can result in symptoms such as fainting, dizziness and shortness of breath. When someone suffers from pulmonary hypertension, it can cause heart failure in the right ventricle of the heart. In other instances, it can be a consequence of other conditions such as heart disease, scleroderma or a pulmonary embolism.