Posterior triangle of the neck

The posterior triangle (or lateral cervical region) is a region of the neck.

Boundaries

It has the following boundaries:

	its apex union of the Sternocleidomastoid and the Trapezius muscles at the superior nuchal line of the occipital bone
in front the posterior border of the Sternocleidomastoideus		behind the anterior border of the Trapezius
	its base the intermediate third of the clavicle

Occipital and subclavian triangles

The posterior triangle is crossed, about 2.5 cm above the clavicle, by the inferior belly of the Omohyoideus, which divides the space into two triangles:

• an upper or occipital triangle
• a lower or subclavian triangle (or supraclavicular triangle)

Contents

A) Nerves and Plexuses:

• Spinal accessory nerve (Cranial Nerve XI)
• Branches of cervical plexus
• Roots and trunks of brachial plexus

B) Vessels:

• Subclavian artery (Third part)
• Transverse cervical artery
• Suprascapular artery
• Terminal part of external jugular vein

C) Lymph Nodes:

• Occipital
• Supraclavicular

D) Muscles:

• Inferior belly of omohyoid muscle

Clinical significance

It is particularly vulnerable to damage at lymph node biopsy, where damage results in an inability to shrug the shoulders or raise the arm above the head (eg, for brushing hair)

See also

• Anterior triangle of the neck

External links

• ()
• - "Identification of the muscles associated with the posterolateral triangle."