At the level of the gastroesophageal junction, the vagus nerves rearrange around the oesophagus to form anterior and posterior vagal trunks. The posterior vagal trunk is derived predominantly from which nerve?
- A Left vagus nerve
- B Right vagus nerve ✓
- C Left recurrent laryngeal nerve
- D Greater splanchnic nerve
Correct answer: B. Right vagus nerve
Explanation
During embryological rotation of the stomach through 90 degrees clockwise, the left vagus nerve, originally anterior, is carried to the anterior surface of the stomach, and the right vagus nerve is carried posteriorly. Hence the anterior vagal trunk derives mainly from the left vagus and the posterior trunk mainly from the right vagus. The left recurrent laryngeal nerve loops under the aortic arch and has no gastric distribution, and the greater splanchnic nerve is purely sympathetic.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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