Overview
The posterior triangle is an
anatomical region of the postero-lateral neck containing several clinically
important structures.
Gross Anatomy
Arteries;
Occipital (apex of triangle)
Transverse cervical (From thyrocervical trunk, anterior to anterior
scalene)
Suprascapular (From thyrocervical trunk, anterior to anterior
scalene)
3rd part of subclavian (deep to prevertebral fascia)
Veins;
Transverse cervical (accompanying its artery)
Suprascapular (accompanying its artery)
External jugular vein (initially superficial to
sternocleidomastoid, it pierces the investing layer near the clavicular head to
enter the triangle at its anterior corner)
Nerves;
Muscular & cutaneous branches of cervical plexus (initially deep
to prevertebral fascia, they enter posterior triangle before piercing investing
layer and coursing superficially)
Lesser & Greater Occipital (near the apex)
Great auricular (deep to mid-SCM, loops around its posterior edge)
Transverse cervical (deep to mid-SCM, loops around its posterior
edge)
Suprascapular (deep to mid-SCM, loops around its posterior edge)
Brachial plexus trunks (deep to prevertebral fascia, closely related to subclavian artery)
Spinal accessory root (pierces sternocleidomastoid, giving off
branches to it, traverses back across triangle running deep to trapezius)
Lymph;
Suboccipital nodes (at the apex)
Supraclavicular nodes (at the base, inferior to omohyoid)
Clinical Anatomy
Whilst some of the structures of the posterior triangle are quite superficial and thus vulnerable to injury (e.g.
external jugular vein), many of the key structures (e.g. – subclavian artery, brachial plexus trunks) lie deep to the
prevertebral fascia where they are relatively
safe.
Quick Anatomy
Key Facts
Aide-Memoire
Charlie Sheen = Epic Bi-winning!
CN XI / Subclavian
artery / EJV / Brachial
plexus trunks