Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The occipital branch of posterior auricular artery passes backward, over the Sternocleidomastoideus, to the scalp above and behind the ear. It supplies the Occipitalis and the scalp in this situation and anastomoses with the occipital artery. In human anatomy, the sternocleidomastoid muscle also known as sternomastoid and commonly abbreviated as SCM, is a paired muscle in the superficial layers of the anterior portion of the neck. It acts to flex and rotate the head. It also acts as an accessory muscle of inspiration, along with the scalene muscles of the neck.