Which nerve arises directly from the C5 root of the brachial plexus, pierces the scalenus medius muscle, and supplies the rhomboid muscles?
- A Suprascapular nerve
- B Long thoracic nerve
- C Dorsal scapular nerve ✓
- D Nerve to subclavius
Correct answer: C. Dorsal scapular nerve
Explanation
The dorsal scapular nerve arises from the B5 root, pierces scalenus medius, descends deep to levator scapulae and supplies the rhomboids (and often levator scapulae). The long thoracic nerve is the tempting distractor: it also comes from root levels, but from B5, B6 and B7 and it runs on serratus anterior, not through scalenus medius. Suprascapular nerve arises from the upper trunk, not the root.
Reference: Snell's Clinical Anatomy by Regions, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.