General Medical Information

Lateral Portion of the Neck

Susan D. John
Michael D. Maves

The dominant structure of the lateral cervical triangle is the spinal accessory nerve. It emanates from the posterior border of the sternocleidomastoid muscle in close association with the splay of nerves of the cervical sensory plexus. It innervates the trapezius muscle on its inferior aspect in close association with the transverse cervical artery or suprascapular artery, which variably supplies the trapezius muscle.