The piriform fossa in the laryngopharynx is an important anatomical landmark for foreign body lodgement. Which nerve runs submucosally in the lateral wall of the piriform fossa and can be anaesthetised topically for rigid laryngoscopy?
- A Recurrent laryngeal nerve
- B Glossopharyngeal nerve
- C Internal branch of superior laryngeal nerve ✓
- D Hypoglossal nerve
Explanation
The internal branch of the superior laryngeal nerve (branch of CN X) enters the larynx by piercing the thyrohyoid membrane and runs submucosally in the lateral wall and floor of the piriform fossa before supplying sensation to the supraglottic larynx. Foreign bodies frequently lodge here and the nerve can be anaesthetised topically. This is the basis of superior laryngeal nerve block for awake intubation. The recurrent laryngeal nerve supplies infraglottic sensation and motor to all intrinsic laryngeal muscles except cricothyroid. The glossopharyngeal nerve supplies the posterior 1/3 of tongue and oropharynx.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.