We have one on the left side, one on the right side and one in the middle. So we have the left side of the body and the right side of the body. So let's begin with our leftmost branch labeled as two A. This is known as our left subclavian artery. Now if we follow the left subclavian artery, it extends all the way to the left shoulder, the left arm and the left hand. So the left subclavian artery brings oxygen to these parts of our body.