Superior Trunk of the Brachial Plexus, Anterior View

Description

Arising from the C5 and C6 ventral rami, the superior trunk of the brachial plexus is shown in anterior orientation in the lower lateral neck as it forms in the interscalene interval between the anterior and middle scalene muscles. Superficially, the sternocleidomastoid crosses obliquely, while the trapezius defines the posterolateral boundary of the cervical region, and the clavicle marks the inferior transition toward the axilla. The trunk sits lateral to the carotid sheath structures and closely related vessels, then courses inferolaterally toward its anterior and posterior divisions near the supraclavicular fossa. A crowded corridor. That spatial relationship is exactly what drives clinical interest: the superior trunk is the usual target in an ultrasound guided interscalene block for shoulder surgery, and an anterior view helps teach why spread around the scalene muscles can also reach the phrenic nerve, producing hemidiaphragmatic paresis. Traction injuries at the C5 to C6 level (classic Erb-Duchenne palsy) preferentially affect this segment, and the illustration supports motor and sensory pattern teaching for deltoid and biceps weakness with lateral arm sensory loss. The proximity to the subclavian vessels also matters during supraclavicular dissection, where a misjudged plane can turn a nerve case into a vascular one. Use this artwork in gross anatomy and regional anatomy curricula when introducing plexus organization from roots to trunks to divisions, and in anesthesia teaching files that compare interscalene versus supraclavicular approaches. It also fits surgical atlases and journal figures discussing thoracic outlet syndrome, clavicular fracture exposure, or brachial plexus exploration in the supraclavicular approach. Anatomical accuracy verified by SciePro's Medical Advisory Board.