Lateral Neck Region, Scalenic Fissure

Lateral Neck Region

Posterior Triangle of the Neck

Consists of 2 triangles, Occipital (Omotrapezoid) and Supraclavicular (Omoclavicular) triangles. This region is known as the Posterior Triangle:

Borders:

• Anterior - m. sternocleidomastoideus
• Posterior - m. trapezius
• Inferior - clavicle

Occipital (Omotrapezoid) Triangle

Posterior Triangle of the Neck (schematic). 1 - CN XI; 2 - erb's point; 3 - Subclavian artery and vein; 4 - brachial plexus; 5 - phrenic nerve; 6 - external jugular vein

Borders:

• Anterior - m. sternocleidomastoideus
• Posterior - m. trapezius
• Inferior - Inferior belly of m. omohyoideus

Contents:

• Cranial Nerve 11 (Accessory nerve)
• Branches of cervical plexus (erb's point)
• Supraclavicular brachial plexus

Supraclavicular (Omoclavicular) Triangle

Borders:

• Superior - Inferior belly of m. omohyoideus
• Anterior - Posterior margin of m. sternocleidomastoideus
• Inferior - clavicle

Contents:

• Subclavian artery
• External jugular vein
• Brachial plexus
• Phrenic nerve

Scalenic Fissure

Scalenic fissure (schematic) - note the position of the brachial plexus (yellow)

Borders:

• Anterior - Anterior scalene muscle
• Posterior - Middle scalene
• Inferior - 1st rib

Contents:

• Brachial Plexus
• Subclavian Artery