Vagocervical complex replacing an absent ansa cervicalis.

Absence of the ansa cervicalis was noticed in only one out of 200 cadavers, and that only on the right side, where it was replaced by the vagocervical complex. This complex was formed by the vagus nerve with the C1 and C2 components from the cervical plexus, giving off a descending branch to supply the infrahyoid muscles of the neck.