Subclavian Nerve, Gross Anatomy

Description

Originating from the superior trunk of the brachial plexus (C5 to C6), the nerve to subclavius descends anteroinferiorly toward the clavicle to reach the subclavius muscle on the inferior surface of the clavicular shaft. The clavicle and first rib form the osseous frame, with the subclavius lying immediately inferior to the clavicle and anterior to the apex of the lung. Nearby, the subclavian artery courses posterior to the anterior scalene, while the subclavian vein runs anterior to that muscle, creating a tight neurovascular corridor at the root of the neck. Spatial relationships matter here. This short branch is easy to overlook in brachial plexus teaching, but it is a reliable landmark for the superior trunk and the preclavicular region when orienting the plexus around the scalene interval and the clavicle. Its proximity to the subclavian vessels makes the anatomy clinically relevant during infraclavicular access and during clavicular fracture fixation, where traction, hematoma, or iatrogenic dissection can disturb adjacent plexus elements. When present, an accessory phrenic contribution traveling with the nerve to subclavius helps explain diaphragmatic paresis that persists after an interscalene block, even when the main phrenic nerve seems spared. Use this plate for brachial plexus modules in gross anatomy and regional anesthesia curricula, for operative anatomy figures in clavicle and thoracic outlet publications, or as a reference in radiology teaching when correlating ultrasound landmarks around the subclavian vein and first rib. Anatomical accuracy verified by SciePro's Medical Advisory Board.