Anterior Scalene Muscle, Gross Anatomy

Description

Running from the anterior tubercles of the cervical transverse processes to the superior surface of the first rib, the anterior scalene (musculus scalenus anterior) stands deep to the sternocleidomastoid and lateral to the prevertebral midline. Its fibers descend inferolaterally, forming the anterior boundary of the interscalene interval, while the middle scalene lies posteriorly and the clavicle and supraclavicular fossa sit inferiorly in the field. Given the head and neck musculature context, adjacent superficial layers such as platysma and trapezius are likely visible, with the anterior scalene positioned as a deeper landmark at the root of the neck. Deep neck anatomy, layered and unforgiving. An anterior oblique to anterolateral perspective on the anterior scalene matters because it frames where clinicians look for neurovascular passage and entrapment at the thoracic inlet. The brachial plexus trunks and subclavian artery course between the anterior and middle scalenes, while the subclavian vein typically runs anterior to the anterior scalene, a relationship that underpins venous access strategies and explains why scalene hypertrophy or a cervical rib can contribute to thoracic outlet syndrome patterns. Anesthesiologists also rely on this topography for interscalene brachial plexus block planning, where proximity to the phrenic nerve along the anterior scalene raises the risk of hemidiaphragmatic paresis. Use this artwork in gross anatomy and regional anatomy teaching to clarify deep-to-superficial layering in the lateral cervical region and to orient learners to the first rib insertion as a palpable surgical landmark. It also suits operative atlases and review materials discussing thoracic outlet decompression, central line placement, and nerve block anatomy for the neck and shoulder. Anatomical accuracy verified by SciePro's Medical Advisory Board.