The anterior triangle is a region of the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

Structure

The triangle is inverted with its apex inferior to its base which is under the chin. Investing fascia covers the roof of the triangle while visceral fascia covers the floor.

Anatomy

Muscles: *

Suprahyoid muscles The suprahyoid muscles are four muscles located above the hyoid bone in the neck. They are the digastric, stylohyoid, geniohyoid, and mylohyoid muscles. They are all pharyngeal muscles, with the exception of the geniohyoid muscle. The digastric is ...

- 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 The mylohyoid nerve (or nerve to mylohyoid) is a nerve of the head. It is a branch of the inferior alveolar nerve. It supplies the mylohyoid muscle, and the Anterior belly of digastric, anterior belly of the digastric muscle. It may also supply m ...

* Posterior:

Facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste ...

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 The pharyngeal arches, also known as visceral arches'','' are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arche ...

* Posterior: 2nd

Divisions

This space is subdivided into four smaller triangles by the

Digastricus The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...

above, and the superior belly of the

Omohyoideus The omohyoid muscle is a muscle that depresses the hyoid. It is located in the front of the neck, and consists of two bellies separated by an intermediate tendon. The omohyoid muscle is proximally attached to the scapula and distally attached to t ...

. These smaller triangles are named: * the

muscular triangle The inferior carotid triangle (or muscular triangle), is bounded, in front, by the median line of the neck from the hyoid bone to the sternum; behind, by the anterior margin of the sternocleidomastoid; above, by the superior belly of the omohyoid. ...

* the

carotid triangle The carotid triangle (or superior carotid triangle) is a portion of the anterior triangle of the neck. Coverings and boundaries It is bounded: * Posteriorly by the anterior border of the Sternocleidomastoid; * Anteroinferiorly, by the superior bel ...

* the submandibular triangle * the

submental triangle The submental triangle (or suprahyoid triangle) is a division of the anterior triangle of the neck. Boundaries It is limited to: * Lateral (away from the midline), formed by the anterior belly of the digastricus * Medial (towards the midline), f ...

Additional images

File:Musculussternocleidomastodieus.png,

Sternocleidomastoid muscle The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the access ...

File:Gray386.png, Muscles of the neck. Anterior view. File:Gray512.svg, The triangles of the neck. (Anterior triangles to the left; posterior triangles to the right. Suprahyoid labeled at left.)

References

External links

* () * {{Authority control Human head and neck Triangles of the neck