Posterior neck triangle

Question 1

Posterior triangle boundaries

Answer 1

• anteriorly by the psoterior edge of the SCM muscle
• posterioly by the anterior edge of the trapezius muscle
• basally by the middle 1/3 of clavicle
• apically by occipital bone

Subdivision: omoclavicular or subclavian triangle (small, inferior to omohyoid)

Question 2

Posterior triangle muscles

Answer 2

Superficial muscles
* SCM
* trapezius
* levator scap
* omohyoid

deep muscles
* splenius capitus
* scalene muscles: posterior scalene, middle scalene, anterior scalene

Question 3

Vessels

Answer 3

• 3rd part of the subclavian artery emerges from between the anterior & middle scalene muscles to cross the base of the posterior triangle. It extends from the lateral border of the anterior scalene muscle of the lateral border of rib 1 where it becomes the axillary artery and continues the upper limb
• transverse cervical and suprascapular arteries: they are both branches from the thyrocervical trunk, which arises from the 1st part if subclavian artery
  -transverse cervical: continues on the deep surface of the trapezius (superficial branch) & continues on deep surface of the rhomboid muscles (deep branch)
  -suprascapular: distributes branches to muscles on the posterior surface of scapula

Question 4

Nerves–Cervical plexus

Answer 4

• formed by anterior rami of cervical nerves C1-C4
• consists of:
  -muscular branches (deep branches), several branches supply prevertebral & lateral vertebral muscles
  -cutaneous branches (superficial branches) visible in the posterior triangle
• lesser occipital n.(sensory): supplies skin of neck & scalp posterior to ears
• great auricular n (sensory): supplies skin of parotid region, ears, & mastoid area
• transverse cervical n. (sensory): supplies lateral and anterior part of neck
• suprascapular n (sensory): supplies the skin over the clavicle and shoulders
• phrenic n ( sensory & motor): supplies diaphragm