For descriptive purposes the neck is divided into anterior and posterior triangles (Fig. 8.161):
The boundaries of the anterior triangle are the anterior border of the sternocleidomastoid muscle, the inferior border of the mandible, and the midline of the neck.
The boundaries of the posterior triangle are the posterior border of the sternocleidomastoid muscle, the anterior border of the trapezius muscle, and the middle one-third of the clavicle.
The fascia of the neck has a number of unique features.