Omohyoid muscle the body of the hyoid bone, lateral to the insertion of the sternohyoid. The central tendon of this muscle varies much in length and form, and is held in position by a process of the deep cervical fascia, which sheaths it, and is prolonged down to be attached to the clavicle and first rib; it is by this means that the angular form of the muscle is maintained. The tendon overlies the internal jugular vein, and can be used as a landmark for this vein during surgery. Doubling; absence; origin from clavicle; absence or doubling of either belly. The inferior
Sternocleidomastoid muscle Sternocleidomastoid muscle The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the accessory nerve. It is given the name "sternocleidomastoid" because it originates at the manubrium of the sternum ("sterno-") and the clavicle ("cleido-"), and has an insertion at the mastoid process of the temporal bone of the skull. The sternocleidomastoid muscle originates from two locations: the manubrium of the sternum and the clavicle. It travels obliquely across the side of