A Clear View of the Middle Scalene Muscle of a Female

Description

Running deep to the sternocleidomastoid, the middle scalene muscle is rendered in lateral cervical view as it descends from the posterior tubercles of the transverse processes of C2 to C7 to its insertion on the superior surface of the first rib, posterior to the subclavian groove. Anterior scalene lies anteromedial, while posterior scalene and levator scapulae sit more posteriorly, with the trapezius forming the superficial posterior contour of the neck. Between the anterior and middle scalenes, the brachial plexus roots and trunks and the subclavian artery occupy the interscalene interval, whereas the subclavian vein remains anterior to anterior scalene and is not a true interscalene structure. Surface landmarks anchor the scene, including the mastoid process region superiorly and the clavicle and first rib inferiorly. Fiber direction is obvious. For clinicians, the middle scalene matters because it defines the lateral wall of the interscalene space and helps set the geometry of thoracic outlet compression, where fibrous bands or a cervical rib can crowd the subclavian artery and brachial plexus and reproduce neurogenic symptoms with arm elevation. Anesthesiologists target this plane during an interscalene brachial plexus block, placing local anesthetic adjacent to the plexus between anterior and middle scalenes while respecting nearby structures such as the phrenic nerve coursing on the anterior scalene and the vertebral artery ascending through the transverse foramina. Small distances. Real consequences. Use this plate in gross anatomy and head and neck dissection teaching to clarify scalene attachments, compartment relationships, and the difference between the interscalene interval and the pre-scalene venous corridor. It also fits vascular, neurosurgical, and regional anesthesia publications discussing thoracic outlet syndrome, cervical rib evaluation, and safe needle trajectories in the lateral neck. Anatomical accuracy verified by SciePro's Medical Advisory Board.