Triangles of the neck

Anatomical regions of the neck

Diagram of the triangles of the neck

Muscles of the neck

Lateral view of neck anatomy

The triangles of the neck are anatomical divisions created by the muscles and bones of the neck. These triangles are used as landmarks in medical examinations and surgical procedures.

Anatomical structure

The neck is divided into two major triangles: the anterior triangle and the posterior triangle. Each of these is further subdivided into smaller triangles.

Anterior triangle

The anterior triangle is bounded by the midline of the neck, the anterior border of the sternocleidomastoid muscle, and the inferior border of the mandible. It is further divided into the following smaller triangles:

• Submental triangle: Located beneath the chin, it is bounded by the anterior belly of the digastric muscle and the hyoid bone.
• Submandibular triangle: Situated beneath the mandible, it is bordered by the mandible and the anterior and posterior bellies of the digastric muscle.
• Carotid triangle: This triangle is important for containing the carotid artery, and is bordered by the sternocleidomastoid muscle, the superior belly of the omohyoid muscle, and the posterior belly of the digastric muscle.
• Muscular triangle: It is bordered by the midline of the neck, the superior belly of the omohyoid muscle, and the sternocleidomastoid muscle.

Posterior triangle

The posterior triangle is located on the lateral aspect of the neck and is bounded by the posterior border of the sternocleidomastoid muscle, the anterior border of the trapezius muscle, and the middle third of the clavicle. It is subdivided into:

• Occipital triangle: Bounded by the sternocleidomastoid, trapezius, and the inferior belly of the omohyoid muscle.
• Supraclavicular triangle: Also known as the subclavian triangle, it is bordered by the clavicle, the inferior belly of the omohyoid muscle, and the sternocleidomastoid muscle.

Clinical significance

The triangles of the neck are clinically significant as they provide a framework for the examination of the neck and the identification of underlying structures. For instance, the carotid triangle is a key area for accessing the carotid artery during medical procedures.

Related pages

• Neck anatomy
• Sternocleidomastoid muscle
• Trapezius muscle

References

• Moore, Keith L.; Dalley, Arthur F.; Agur, Anne M. R. (2013). Clinically Oriented Anatomy. 7th edition. Lippincott Williams & Wilkins.
• Standring, Susan (2015). Gray's Anatomy: The Anatomical Basis of Clinical Practice. 41st edition. Elsevier.