It curves around the posterior border of the sternocleidomastoideus muscle, then pierces the fascia of the neck before dividing into two branches.

[1] It curves around the posterior border of the sternocleidomastoideus muscle[1] about its middle, and, passing obliquely forward beneath the external jugular vein to the anterior border of the muscle,[citation needed] it perforates the deep cervical fascia before dividing into an ascending branch and a descending branch[1] beneath the platysma.

[1] During dissection, the sternocleidomastoid muscle is the landmark, with the transverse cervical nerve passing horizontally over this muscle from Erb's point.

[citation needed] The nerve provides sensory innervation to the skin of the anterior neck between the chin and the sternum.

[1] This article incorporates text in the public domain from page 927 of the 20th edition of Gray's Anatomy (1918)