The middle scalene is one of the scalene muscles of the neck. It is the largest of the three scalene muscles and consists of several muscle bellies arising from the cervical spine.
- Attachments: Originates from the posterior tubercles of the transverse processes of C2-C7 and attaches to the scalene tubercle of the first rib.
- Function: Elevation of the first rib. Ipsilateral contraction causes ipsilateral lateral flexion of the neck.
- Innervation: Anterior rami of C3-C8.
- Blood Supply: Ascending cervical branch of inferior thyroid artery