Omoclavicular Triangle of the Male Neck

Description

Oblique lateral neck anatomy is presented with the omoclavicular (subclavian, supraclavicular) triangle defined between the inferior belly of omohyoid superiorly, the posterior border of sternocleidomastoid anteromedially, and the clavicle inferiorly. Deep to the superficial fascia and platysma, the prevertebral fascia forms a floor over scalenus medius and scalenus anterior, with the subclavian artery coursing posterolateral to the anterior scalene while the subclavian vein lies more anterior and inferior as it approaches the venous angle. The phrenic nerve tracks on the anterior surface of scalenus anterior, while trunks of the brachial plexus and the supraclavicular nerves occupy the posterior triangle lateral to the sternocleidomastoid. Small space. High stakes. This side view matters because the omoclavicular triangle is the working corridor for infraclavicular and supraclavicular access to the subclavian vessels and adjacent neural structures, and the anatomy changes quickly with head rotation, shoulder depression, and muscular hypertrophy. It is also the region implicated in thoracic outlet syndrome, where compression can occur between the scalene muscles and first rib, and where iatrogenic pneumothorax is a real risk during subclavian central venous catheter placement due to the nearby cervical pleura and lung apex. Ho’s triangle terminology appears in some surgical and anesthesia texts, so clear topographic boundaries help reconcile naming across curricula. Use this illustration for gross anatomy teaching of the lateral cervical region and posterior triangle, for operative anatomy notes in vascular surgery and anesthesiology (subclavian line placement, supraclavicular brachial plexus block), and for radiology correlation when mapping supraclavicular lymph nodes and vascular landmarks on ultrasound. Anatomical accuracy verified by SciePro's Medical Advisory Board.