The sternocleidomastoid (sternocleidomastoideus; sternomastoid) muscle is located in the neck. It is a thin, broad muscle that narrows at the center. It originates from two heads, one from the sternum and and one from the clavicle , and runs upward, inserting into the mastoid process. The sternocleidomastoid muscle is innervated by the accessory nerve and the cervical plexus. It is supplied by the occipital arteryans the superior thyroidartery. This muscle is used to tilt the head from side to side. Research Sternocleidomastoid
In anatomy, the sternum is a flat, blade-like bone located at the center of the chest. It serves as the anterior site of articulation for the ribs via cartilaginous connections, called costal cartilage. The pectoralis major also anchors to the sternum, giving the shoulder joint much of its strength during flexion of the arm. The sternum features two articulations in addition to its costal articulations. One of these, called the manubriosternal joint, is between the body of the sternum and the broader upper section, called the manubrium. The manubrium of the sternum articulates with the clavicles and the sternocleidomastoid, sternohyoid, and sternothyroidmuscles connect here. The lower articulation is called the xiphisternal joint, and is between the body of the sternum and a small, teardrop-shaped bone called the xiphoid process. The xiphoid process anchors the rectus abdominis, the transverse thoracic, and the diaphragmmuscles, responsible for much of the muscular expansion and contraction of the abdomen. Research Sternum
 
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