sternocleidomastoid

A paired muscle in the superficial layers of the anterior portion of the neck. It acts to flex and rotate the head. It also acts as an accessory muscle of inspiration, along with the scalene muscles of the neck. [WP,unvetted]. Every claim on this page comes from the Leumas anatomy graph and carries its source.

What the sternocleidomastoid is

A paired muscle in the superficial layers of the anterior portion of the neck. It acts to flex and rotate the head. It also acts as an accessory muscle of inspiration, along with the scalene muscles of the neck. [WP,unvetted]. The atlas records it as a muscle at the organ scale in the human body.

Where the sternocleidomastoid is

It sits in the neck, within the muscular system. Positioned deliberately as part of this species body plan.

What the sternocleidomastoid connects to

The atlas records 8 typed relationships for it, across 5 kinds of connection. part of muscle of shoulder.

Supply and innervation

Innervation: cervical nerve plexus.

Also called

Also recorded as SCM, sterno-mastoid, sternocleidomastoid muscle, sternomastoid, sternomastoid muscle and musculus sternocleidomastoideus, and 8 more. Searching any of those names reaches this page.

Source

Uberon multi-species anatomy ontology (Mungall et al.), CC BY 4.0. Term UBERON:0001128, version 2026-06-19, retrieved 2026-08-24. Licence: CC-BY-4.0.

• Part of: muscle of shoulder.
• A kind of: anatomical structure, muscle of neck and skeletal muscle organ, vertebrate.
• originates from: clavicle bone and manubrium of sternum.
• Innervated by: cervical nerve plexus.
• inserts into: mastoid process of temporal bone.

Questions

Where is the sternocleidomastoid?

It sits in the neck, within the muscular system. Positioned deliberately as part of this species body plan.

What does the sternocleidomastoid connect to?

Part of: muscle of shoulder.

Is the sternocleidomastoid the same in other species?

Leumas holds the same relationship vocabulary for every species it carries, so where another dataset records this structure you can put the two side by side on /compare.