Sternocleidomastoid Muscle & Accessory & Cervical Plexus NervesThe Sternocleidomastoid muscle, abbreviated SCM and also known as the Sternomastoid is a long muscle on each side of the neck with two heads that allows head rotation in both directions.
Location Of The Sternocleidomastoid MusclesThe Sternocleidomastoid is a thick, long muscle located in the neck, originating in the breastbone or sternum manubrium and clavicle or collarbone and running alongside the neck to the mastoid process of the temporal bone located in the head or skull behind the ears. The Sternocleidomastoid actually starts off separated into two parts or heads which gradually become one thick muscle which inserts itself into the lateral surface of the mastoid process by a tough tendon.
Functions Of The Accessory & Cervical Plexus NervesThe Sternocleidomastoid muscle works in conjunction with the Accessory nerve and cervical plexus nerve, both of which have very specific jobs or purposes for aiding in the muscles movement. The Accessory nerve gives the Sternomastoid muscle it's motor functions and enables movement while the cervical plexus nerve provides the Sternocleidomastoid muscle sensory information, or sensation and sense of position.