Borders:
- - Anterior - posterior margin of sternocleidomastoid muscle
- - Posterior - anterior margin of trapezius muscle
- - Inferior - middle one-third of clavicle
Subdivisions:
- - Occipital triangle
  - borders
    - Anterior - posterior margin of sternocleidomastoid muscle
    - Posterior - anterior margin of trapezius muscle
    - Inferior - inferior belly of omohyoid muscle
  - Contents
    - Accessory nerve (CN XI), branches of the cervical plexus, upper most part of brachial plexus, supraclavicular nerve
- - Supraclavicular (omoclavicular) triangle
  - BORDERS
    - Superior - inferior belly of omohyoid muscle
    - Anterior - posterior edge of sternocleidomastoid muscle
    - Inferior - clavicle
  - CONTENTS
    - Third part of the subclavian artery, brachial plexus trunks, nerve to subclavius muscle, lymph nodes
contents
- Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus

POSTERIOR TRIANGLE OF NECK

SIDE OF NECK