C-3 thru C-6 to first rib.
The scalene muscles originate from the transverse processes from the cervical vertebrae of C2 to C7 and insert onto the first and second ribs, and used to be known as the lateral vertebral muscles. Wiki
First and second ribs.
The anterior scalene muscle (or the scalenus anterior) is inserted by a narrow, flat tendon into the scalene tubercle on the inner border of the first rib, and into the ridge on the upper surface of the second rib in front of the subclavian groove.
The middle scalene, (or scalenus medius) descends along the side of the vertebral column to insert by a broad attachment into the upper surface of the first rib, between the tubercle and the subclavian groove.
The posterior scalene, (or scalenus posterior) is inserted by a thin tendon into the outer surface of the second rib, behind the attachment of the anterior scalene. It is occasionally blended with the middle scalene.
Elevates first rib during deep inhalation.
The action of the anterior and middle scalene muscles is to elevate the first rib and laterally flex (bend) the neck to the same side; the action of the posterior scalene is to elevate the second rib and tilt the neck to the same side. They elevate the upper ribs and so they also act as accessory muscles of respiration, along with the sternocleidomastoids.
Innervation – Nerve control
Cervical nerves (C3-C6).
The anterior scalene muscle is supplied by the anterior ramus of cervical nerve 5 and 6.
The posterior scalene is supplied by cervical nerves C6, C7 and C8.
Ascending cervical artery (branch of Inferior thyroid artery).
The inferior thyroid artery is an artery in the neck which arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle. Wiki
Pictures of muscles
Trigger Point Referrals