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Sternocleidomastoid
Other Terms:
Sternocleidomastoid muscle,
Musculus sternocleidomastoideus,
Muscle sterno-cléido-mastoïdien
Muscle parts
None
Latin name
Musculus sternocleidomastoideus
Latin muscle parts
None
Group
Branchial arch muscle – transition arch
Etymology
The English name for this muscle is the muscle of the breast, the clavicle bone, and the breast-like process. The term sterno comes from the Latin word sternon meaning “breast or chest,” the word cleido, refers to “the clavicle,” and the word mastoid comes from the Greek mastos meaning “breast” and eidos meaning “shape or form.”
Origin
Anterior upper margin of the manubrium of the sternum; superior aspect of the medial third of the clavicle
Insertion
Lateral side of the mastoid process and lateral portion of the superior nuchal line
Action
Unilaterally it extends (sternal fibers) or flexes (clavicular fibers) the head and rotates it toward the opposite shoulder; flexes and extends the head; raises rib cage
Nerve supply
Accessory nerve (Cranial nerve XI) and ventral rami of cervical spinal nerves (C2, 3, and 4)
Blood supply
From superior to inferior the muscle is supplied by the occipital branch of the posterior auricular, the sternocleidomastoid branches of the occipital artery, the sternocleidomastoid artery from the superior thyroid artery (sometimes arising directly from the external carotid artery), and from the suprascapular and superficial cervical arteries from the subclavian artery.
Latin
Musculus sternocleidomastoideus
French
Muscle sterno-cléido-mastoïdien