Vessels of Posterior Triangle of Neck
Arteries
Subclavian Artery — Third Part
- The 3rd part of the subclavian artery is the only part in the posterior triangle
- Located in the subclavian (supraclavicular) triangle
- Extends from lateral border of scalenus anterior to the outer border of the 1st rib (where it becomes the axillary artery)
- Relations: Lies on floor (scalenus medius); brachial plexus trunks are above and behind; subclavian vein is anterior and inferior
- Usually gives no branches in its 3rd part (all branches arise from 1st or 2nd part)
Transverse Cervical Artery
- Branch of thyrocervical trunk (from subclavian artery 1st part)
- Crosses the posterior triangle horizontally, superficial to the brachial plexus and scalenus anterior
- Divides into superficial and deep branches supplying trapezius and rhomboids
Suprascapular Artery
- Also from thyrocervical trunk
- Runs laterally and inferiorly across the posterior triangle, crossing anterior to the brachial plexus
- Accompanies suprascapular nerve to the supraspinous fossa
Veins
External Jugular Vein (EJV)
- Formation: Behind the auricle by union of posterior auricular vein and posterior division of retromandibular vein
- Course: Descends vertically in the superficial fascia (superficial to SCM) → crosses SCM obliquely → passes through the investing fascia (roof) of the posterior triangle → terminates in the subclavian vein
- Tributaries: Posterior external jugular vein, transverse cervical vein, suprascapular vein, anterior jugular vein (via jugular venous arch)
- Clinical: Distension = raised JVP; used to estimate central venous pressure
Lymph Nodes
| Group | Location | Drainage |
|---|---|---|
| Occipital nodes | Near apex of triangle, on trapezius | Scalp (occipital region) |
| Supraclavicular nodes | Along transverse cervical vessels | Breast, lung, stomach (left supraclavicular = Virchow’s node) |
| Accessory chain nodes | Along accessory nerve | Head and neck |
Virchow’s node (Troisier’s sign): Left supraclavicular lymphadenopathy = metastasis from abdominal malignancy (especially stomach). Drains via thoracic duct into left subclavian vein.