During thoracic surgery, the surgeon identifies a nerve looping around the arch of the aorta before ascending in the tracheoesophageal groove. Which nerve is this?

• A Right recurrent laryngeal nerve
• B Left recurrent laryngeal nerve ✓
• C Left phrenic nerve
• D Left internal laryngeal nerve

Explanation

The left recurrent laryngeal nerve branches from the left vagus as the vagus crosses the aortic arch, loops under the arch just posterior to the ligamentum arteriosum, and ascends in the groove between the trachea and esophagus. The right recurrent laryngeal nerve instead hooks around the right subclavian artery, so it never enters the thorax proper. This asymmetry explains why apical lung tumors cause hoarseness more often on the left.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.