Which structure does the left recurrent laryngeal nerve loop around, potentially leading to hoarseness when enlarged?

Which structure does the left recurrent laryngeal nerve loop around, potentially leading to hoarseness when enlarged?

• A. Arch of the Aorta
• B. Ligamentum arteriosum
• C. Pulmonary trunk
• D. Superior vena cava

Answer: (C)

The left recurrent laryngeal nerve travels down the thorax and makes a distinctive loop under a large artery before ascending to the larynx. It hooks around the arch of the aorta, just lateral to the ligamentum arteriosum, then fibers run in the left tracheoesophageal groove to reach the larynx. Because of this intimate relationship, enlargement or aneurysm of the arch of the aorta can compress the nerve and produce hoarseness due to impaired innervation of the intrinsic laryngeal muscles. The pulmonary trunk and the superior vena cava aren’t the structures the nerve loops around, and while the ligamentum arteriosum is nearby, the critical loop is around the arch of the aorta.

The left recurrent laryngeal nerve travels down the thorax and makes a distinctive loop under a large artery before ascending to the larynx. It hooks around the arch of the aorta, just lateral to the ligamentum arteriosum, then fibers run in the left tracheoesophageal groove to reach the larynx. Because of this intimate relationship, enlargement or aneurysm of the arch of the aorta can compress the nerve and produce hoarseness due to impaired innervation of the intrinsic laryngeal muscles. The pulmonary trunk and the superior vena cava aren’t the structures the nerve loops around, and while the ligamentum arteriosum is nearby, the critical loop is around the arch of the aorta.