And that is to ensure that all the blood gets to the cells of our left shoulder and our left arm. Now what about the middle branching point on the arch? This right here labeled as two B, is known as our left common carotid artery. And this artery brings our oxygenated blood filled with nutrients to the head of our body. For example, the thyroid and a parathyroid glands. These organs receive blood from this common carotid artery.