Coeliac Plexus Anatomy — FRCA Primary MCQ

Correct answer: D — It lies retroperitoneally over the anterolateral aorta at T12–L1, around the origins of the coeliac trunk and superior mesenteric artery.

Explanation lettering: C = shown as A · A = shown as B · D = shown as C · B = shown as D

B is correct. The coeliac plexus is a retroperitoneal autonomic network lying mainly over the anterolateral surface of the abdominal aorta, usually at T12–L1 and around the origins of the coeliac trunk and superior mesenteric artery. Its position varies between individuals. It contains sympathetic fibres arriving principally through the greater, lesser and least thoracic splanchnic nerves, visceral afferents, and parasympathetic fibres from the vagal trunks. It is therefore neither exclusively sympathetic nor exclusively parasympathetic. The thoracic splanchnic nerves travel initially in the retrocrural region but pass through the diaphragmatic crura to reach the plexus; the plexus itself is not within the spinal canal or posterior to the aorta. It supplies abdominal viscera rather than providing somatic innervation to the abdominal wall.

Reference: Hisano N et al. Retroperitoneal fasciae as barriers for nerve and arterial passages connecting the retroperitoneal region to the peritoneal organs, 2024. https://pubmed.ncbi.nlm.nih.gov/38450739/