The Anterior Triangle and Root of Neck

The anterior triangle and of the neck


Anteriorly Anteromedian line of the neck
Posteriorly Anterior border of the .sternocleidomastoid muscle
Superiorly Inferior border of mandible
Apex Jugular notch



  • Digastric triangle (1)
  • Carotid triangle (2)
  • Muscular triangle (3)
  • Submental triangle (4)

Muscular Triangle



Medially the midline
Inferolaterally Anterior border of the .sternocleidomastoid muscle
Superolaterally superior belly of omohyoid


1) Infrahyoid muscles (strap muscles).

•  Sternohyoid

•  Sternothyroid

•  Thyrohyoid

•  Omohyoid* forming part of the boundary.


  • These muscles are innervated by ansa cervicalis (c1-c3) except thyrohyoid that is innervated by C1 via Hypoglossal nerve. They depress the hyoid bone and larynx during swallowing and speaking, anchoring it in position

2) The anterior jugular veins, run in both sides of the midline. They are joined by the jugular arch at the suprasternal notch.

Identify the structures labelled 4-6