Triangles of the neck
Completing this study unit will allow you to:
- Identify the anatomical borders of the anterior and posterior triangles of the neck.
- List the structures located in each of the triangles of the neck.
- Describe the course of neurovascular structures travelling through the triangles of the neck.
The triangles of the neck allow us to better understand and categorise the exact anatomical location of the organs, muscles and neurovascular structures passing through the neck. The midline of the neck, which is the line running from the mandibular symphysis to the manubrium sterni, divides the neck into two symmetrical halves, while the sternocleidomastoid muscle further divides each half into an anterior and posterior triangle.
The anterior triangle contains mainly vessels, nerves and lymphatics that course between the head and the thorax, while the structures contained in the posterior triangle are mainly associated with the upper limb. Each of these triangles is further subdivided into smaller triangles or regions. Knowledge about their anatomical borders and contents is important in clinical examinations of the neck region, such as the palpation of the pulse of neck arteries or the identification of enlarged lymph nodes.
Watch the following video to expand your knowledge on the triangles of the neck!
Take a quiz
Test your newly acquired knowledge with the quiz below!
Looking for an additional challenge? Why not try the following quiz on the anatomy of the entire neck:
Explore the triangles of the neck as well as their muscular and neurovascular components in the atlas galleries below:
Triangles of the neck
Bones and muscles of the neck
Neurovascular structures of the neck
Anterior: Anterior belly of digastric muscle
Posterior: Posterior belly of the digastric muscle
Floor: Mylohyoid and hyoglossus muscles
Contents: Submandibular glands and lymph nodes, facial artery and vein, submental artery and vein, mylohyoid nerve, geniohyoid muscle, hyoglossus muscle, lingual artery, deep lingual vein
Lateral: Anterior belly of the digastric muscle
Inferior (base): Hyoid bone
Superior (apex): Mandibular symphysis
Floor: Mylohyoid muscle
Contents: Submental veins, submental lymph nodes
|Muscular (omotracheal) triangle
Superior: Hyoid bone
Superolateral: Superior belly of omohyoid muscle
Inferolateral: Sternocleidomastoid muscle
Base: Median line of the neck
Apex: Junction of the sternocleidomastoid and superior belly of the omohyoid muscles
Contents: Infrahyoid muscles (thyrohyoid, sternothyroid, sternohyoid), thyroid gland, parathyroid gland, superior thyroid artery and vein, inferior thyroid artery and vein, anterior jugular vein
Anterior: Superior belly of the omohyoid muscle
Superior: Posterior belly of digastric muscle
Posterior: Anterior border of the sternocleidomastoid muscle
Floor: Thyrohyoid, hyoglossus, middle and inferior constrictors of the pharynx muscles
Contents: Carotid sheath containing the common carotid artery, internal jugular vein, vagus nerve (CN X), deep cervical lymph nodes; superior thyroid artery, lingual artery, facial artery, ascending pharyngeal artery, occipital artery; hypoglossal nerve (CN XII), accessory nerve (CN XI), ansa cervicalis
|Omoclavicular (supraclavicular) triangle
Superior: Inferior belly of omohyoid muscle
Anterior: Sternocleidomastoid muscle
Floor: Anterior and middle scalene muscles
Contents: Subclavian artery, transverse cervical artery, dorsal scapular artery, external jugular vein, brachial plexus, phrenic nerve, supraclavicular lymph nodes
|Occipital (omotrapezius) triangle
Anterior: Posterior border of sternocleidomastoid muscle
Posterior: Trapezius muscle
Inferior: Inferior belly of omohyoid muscle
Floor: Splenius capitis, levator scapulae and middle scalene muscles
Contents: Occipital artery, transverse cervical artery, accessory nerve (CN XI), brachial plexus, cervical plexus, phrenic nerve