General Medical Information

Cervical Triangles

Susan D. John
Michael D. Maves

The prominent landmarks of the neck are the hyoid bone, the thyroid cartilage, the trachea, and the sternocleidomastoid muscles. The sternocleidomastoid muscles divide each side of the neck into two major triangles, anterior and posterior. The anterior triangle of the neck may be further delimited by the strap muscles into the superior and inferior carotid triangles. The posterior triangles or lateral triangles of the neck are formed by the posterior border of the sternocleidomastoid muscle anteriorly, the clavicle inferiorly, and the anterior border of the trapezius muscle posteriorly. The omohyoid muscle divides this triangle of the neck into a small inferior subclavian triangle and a larger posterior occipital triangle. Deep to these muscles are the scalenes, which form much of the muscle mass of the posterior and lateral portions of the neck. The brachial plexus and subclavian artery course between the anterior and middle scalene muscles. The subclavian vein courses anteriorly to the anterior scalene muscle.