Posterior Scalene Under the Skin

Description

Shown from a posterior cervical perspective in an adult male, the superficial skin is removed to expose the posterior triangle of the neck with the trapezius and more superficial fascial layers opened to reveal the deeper lateral cervical musculature. The posterior scalene sits deep and slightly posterior to the middle scalene, running inferolaterally from the posterior tubercles of the mid cervical transverse processes (classically C4 to C6) to the external surface of the second rib. Medial to the scalenes lie the splenius capitis and semispinalis capitis over the cervical spinous processes, while laterally the muscle plane approaches the levator scapulae as it descends toward the superior angle of the scapula. Small but specific. For teaching cervical anatomy, this view clarifies why the scalene compartment matters when you are thinking about thoracic outlet symptoms and lateral neck procedures. The posterior scalene forms part of the muscular envelope around the interscalene space, a region traversed by the roots and trunks of the brachial plexus and closely related to the subclavian artery and first rib; hypertrophy, fibrous bands, or a cervical rib can shift these relationships and contribute to neurogenic thoracic outlet syndrome. It also helps explain needle trajectories for interscalene brachial plexus block, where staying within the correct fascial plane is the difference between effective analgesia and unintended spread. Use this illustration in head and neck anatomy courses, anesthesia training modules, and surgical atlases covering posterior triangle exposure, lymph node biopsy approaches, or scalenectomy planning. It also fits well in radiology teaching files that correlate neck dissection layers with axial CT or ultrasound landmarks for the scalenes. Anatomical accuracy verified by SciePro's Medical Advisory Board.