After branching from the thyrocervical trunk, the transverse cervical artery passes laterally and slightly posteriorly across the base of the posterior triangle anterior to the anterior scalene muscle and the brachial plexus. Reaching the deep surface of the trapezius muscle, it divides into superficial and deep branches:
The superficial branch continues on the deep surface of the trapezius muscle.
The deep branch continues on the deep surface of the rhomboid muscles near the medial border of the scapula.