The posterior cervical triangle is bounded:

• Anteriorly by the posterior border of the sternocleidomastoid muscle
• Posteriorly by the anterior border of the trapezius muscle
• Inferiorly by the middle third of the clavicle.

The arteries in the posterior triangle are the:

• Third part of the subclavian artery
• Transverse cervical artery
• Suprascapular artery
• Occipital artery.

The nerves in the posterior triangle include:

• supraclavicular part of the brachial plexus.
• N. accessorius

• Cervical plexus
• Lesser occipital nerve
• Great auricular nerve
• Transverse cervical nerve
• Supraclavicular nerves
• Phrenic nerve.