# The origin of clavicular head of sternocleidomastoid muscle is from the: A. Medial one third of the inferior surface of the clavicle B. Lateral one third of the inferior surface of the clavicle C. Medial one third of the superior surface of the clavicle D. Lateral one third of the superior surface of the clavicle The correct answer is C. Medial one third of the superior surface of the clavicle. Origin of Sternocleidomastoid Muscle 1. The sternal head is tendinous and arises from the superolateral part of the front of the manubrium sterni. 2. The clavicular head is musculotendinous and arises from the medial one third of the superior surface of the clavicle. Insertion of Sternocleidomastoid Muscle It is inserted a) by a thick tendon into the lateral surface of the mastoid process from its tip to its superior border, and b) by a thin aponeurosis into the lateral half of the superior nuchal line of the occipital bone. Nerve Supply of Sternocleidomastoid The spinal...