Two models showing the arrangement of the facial and neck muscles. The temporalis, a large fan- shaped muscle which covers the temporal part of the cranium, is shown on the model at right; it is responsible for the movements of the mandible. On the same model the sternocleidomastoid muscle is seen in the neck; it has a cylindrical shape and runs obliquely from the posterior lower part of the cranium to the anterior part of the collar bone. The trapezium, the triangular muscle extending over the back of the neck, controls the position of the shoulder blade during active use of the upper limb. The parotid gland is seen close to the ear on the model at left.