POSTERIOR TRIANGLE OF THE NECK

Question 1

BOUNDARIES

Answer 1

1. A= posterior surface of the sternocleidomastoid
2. P= anterior surface of trapezius
3. I= middle 1/3 of the clavicle

Question 2

the fascia of the triangle

Answer 2

The posterior triangle of the neck is covered by the investing layer of fascia, and the floor is formed by the prevertebral fascia

Question 3

contents of the triangle

Answer 3

1. inferior belly of omohyoid muscle that divides the triangle into two
2. splenius capitis muscle
3. levator scapulae muscle
4. 3 scalene muscles
5. brachial plexus

Question 4

Apex: where the SCM and trapezius meet on the superior

nuchal line of the occipital bone

Answer 4

true

Question 5

The occipital triangle is so-called because the occipital

artery appears in its apex.

Answer 5

true

Question 6

The omoclavicular (subclavian) triangle is indicated on the surface of the neck by the supraclavicular fossa. Because the
the third part of the subclavian artery is located in this region, the
omoclavicular triangle is often called the subclavian triangle

Answer 6

true

Question 7

superficial contents of the occipital triangle

Answer 7

• Terminal part of External Jugular Vein (EJV) as it enters the superior Occipital Triangle, passing over the
inferior belly of the omohyoid into the omoclavicular triangle*

• Superiorly, 4 cutaneous branches of the Cervical Plexus (C1-C4)
o Lesser Occipital Nerve 
o Great Auricular Nerve
o Intermediate Supraclavicular Nerve 
o Deep Transverse Cervical Nerve 
• Superficial Cervical Lymph nodes*

Question 8

deep contents of the occipital triangle

Answer 8

The occipital artery in the apex
• Transverse Cervical Artery (Cervicodorsal Trunk) *
• Spinal Accessory Nerve (CN XI)
• Phrenic Nerve (passing laterally to medial over the anterior scalene muscle) *
• Roots & Trunks of the Brachial Plexus as it passes between the middle and anterior scalene muscles

Question 9

superficial contents of omoclavicular triangle

Answer 9

The inferior part of the External Jugular
Vein *
• Superficial Cervical Lymph Nodes

Question 10

deep contents of OMO

Answer 10

The third part of the Subclavian Artery & 
Vein
• Suprascapular Artery, Vein and 
Nerve
• Phrenic Nerve *
• Supraclavicular Lymph Nodes
• Trunks of Brachial Plexus