Anterior triangle of the neck

Anterior triangle of the neck
Anterior triangle of the neck
	Anterior triangle
	Side of neck, showing chief surface markings. (Nerves are yellow, arteries are red.)
Details
Identifiers
Latin	trigonum cervicale anterius; trigonum colli anterius; regio cervicalis anterior
TA98	A01.2.02.002
TA2	230
FMA	57777
	Anatomical terminology [edit on Wikidata]

The anterior triangle is a region of the neck.

Structure

The triangle is inverted with its apex inferior to its base which is under the chin.^[1]

Inferior boundary (apex)	Jugular notch in the manubrium of the sternum
Anterior boundary	Midline of the neck from chin to the jugular notch
Posterior boundary	The anterior margin of sternocleidomastoid
Superior boundary (base)	The lower border of the body of the mandible, and a line extending from the angle of the mandible to the mastoid process

Investing fascia covers the roof of the triangle while visceral fascia covers the floor.

Anatomy

Muscles:

Suprahyoid muscles - Digastric (Ant and post belly), mylohyoid, geniohyoid and stylohyoid.
Infrahyoid muscles - Omohyoid, sternohyoid, sternothyroid, and thyrohyoid.

Nerve supply

2 Bellies of digastric

Anterior: Mylohyoid nerve
Posterior: Facial nerve

Stylohyoid: by the facial nerve, by a branch from that to the posterior belly of digastric.

Mylohyoid: by its own nerve, a branch of the inferior alveolar (from the mandibular division of trigeminal nerve), which arises just before the parent nerve enters the mandibular foramen, pierces the sphenomandibular ligament, and runs forward on the inferior surface of the mylohyoid, supplying it and the anterior belly of the digastric.

Geniohyoid: by a branch from the hypoglossal nerve consisting of fibres from the C1 nerve.

Sternohyoid, omohyoid, sternothyroid are supplied by ansa cervicalis.

Thyrohyoid: by a branch of hypoglossal nerve but the fibres are all 'hitch-hiking' from C1.

Development

Anterior: 1st pharyngeal arch
Posterior: 2nd pharyngeal arch

Divisions

This space is subdivided into four smaller triangles by the digastricus above, and the superior belly of the omohyoideus.

These smaller triangles are named:

Additional images

Sternocleidomastoid muscle
Muscles of the neck. Anterior view.
The triangles of the neck. (Anterior triangles to the left; posterior triangles to the right. Suprahyoid labeled at left.)

References

^ Standring, Susan (2016). Gray's anatomy: the anatomical basis of clinical practice (41 ed.). Elsevier Limited. pp. 442–474. ISBN 978-0-7020-5230-9.

This article incorporates text in the public domain from page 563 of the 20th edition of Gray's Anatomy (1918)

External links

lesson5 at The Anatomy Lesson by Wesley Norman (Georgetown University) (necktriangle)
lesson6 at The Anatomy Lesson by Wesley Norman (Georgetown University)

[1] Standring, Susan (2016). Gray's anatomy: the anatomical basis of clinical practice (41 ed.). Elsevier Limited. pp. 442–474. ISBN 978-0-7020-5230-9.

[1]