A 52-year-old man develops Horner syndrome (ptosis, miosis, anhidrosis) after a radical neck dissection. The sympathetic fibres responsible for facial sweating and vasomotor control of the face travel along which vessel?
- A Internal carotid artery only
- B External carotid artery only
- C Both internal and external carotid arteries ✓
- D Vertebral artery
Correct answer: C. Both internal and external carotid arteries
Explanation
Postganglionic sympathetic fibres from the superior cervical ganglion travel along both the internal carotid artery (to the orbit and forehead) and the external carotid artery (to the face, scalp, and neck) via their respective plexuses. Facial sweating and vasomotor control depend on the external carotid plexus. Injury in neck dissection disrupts both distributions, explaining the complete Horner syndrome with facial anhidrosis. Ref: Gray's Anatomy, 42nd ed, p 761.
Reference: Gray's Anatomy, 42nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.