Posterior triangle of neck
Anatomy · Topic 29
Source: NMC CBME Curriculum 2024 · Volume I · Anatomy · Topic 29 · combined PDF page 126
Practice questions
- Which structure forms the anterior boundary of the posterior triangle of the neck?
- The inferior boundary, or base, of the posterior triangle is formed by which structure?
- Which structure divides the posterior triangle into occipital and omoclavicular subdivisions?
- A structure is found in the lower subdivision of the posterior triangle, between the inferior belly of omohyoid and the clavicle. Which subdivision is this?
- Which pairing correctly identifies the roof and floor of the posterior triangle?
- During an operation in the posterior triangle, a superficially crossing nerve is identified emerging from the posterior border of sternocleidomastoid and heading toward trapezius. Which nerve is it?
- A patient develops shoulder droop and difficulty shrugging after posterior-triangle lymph-node surgery. Injury to which nerve best explains these findings?
- The cutaneous branches of the cervical plexus most commonly emerge near which surface landmark?
- The trunks of the brachial plexus pass through the lower posterior triangle in relation to which muscle?
- Which set of roots forms the upper trunk of the brachial plexus?
- A penetrating injury in the posterior triangle produces weakness across several terminal nerves of the upper limb. Which structure is most directly at risk in the deep lower triangle?
- Which muscle is supplied motorly by the spinal accessory nerve and is a principal boundary of the posterior triangle?
- Which nerve descends on the anterior surface of scalenus anterior?
- At the first rib, where does scalenus anterior insert in relation to the subclavian artery groove?
- The inferior belly of omohyoid is tethered near the clavicle by which structure?
- Levator scapulae contributes to the floor of the posterior triangle. Its superior attachments are principally to which structures?
- A patient has an adducted, medially rotated arm with elbow extension after traction injury to the neck. Which lesion pattern is most likely?
- Which root levels are classically implicated in Klumpke palsy?
- A patient with a lower-trunk brachial plexus injury has intrinsic hand weakness and ipsilateral ptosis with miosis. Which associated structure is most likely involved to explain the ocular findings?
- A child has a persistent head tilt to the left and the chin rotated to the right. Shortening of which muscle best accounts for this posture?
- Fibromatosis coli is most directly associated with which muscle in the context of congenital muscular torticollis?
- Which combination correctly describes the typical course of the external jugular vein in the lateral neck?
- During dissection, a superficial vein near the clavicle appears to form a loop with the transverse cervical vein and gives rise to two channels draining separately to the subclavian vein. How should this finding be interpreted?
- A surgeon encounters a vein running along the anterior border of trapezius and draining into the transverse cervical vein rather than the external jugular vein. Which vessel variant matches this description?
- Which statement about the reported unusual posterior-triangle venous arrangement is justified by the evidence?
- Which artery is commonly encountered in the posterior triangle and crosses its lower part toward the scapular region?
- A structure passes posterior to scalenus anterior and anterior to scalenus medius, while another large vessel passes anterior to scalenus anterior. Which pair is correctly identified?
- Which statement best explains why the spinal accessory nerve is considered vulnerable during posterior-triangle procedures?
- A 2026 cadaveric study proposed a surface-based danger zone for the spinal accessory nerve using palpable landmarks. What is the most appropriate clinical interpretation of such a zone?