The diaphragmatic crura lie anterior to which major abdominal vessel?

• A. The aorta
• B. The IVC
• C. The portal vein
• D. The superior mesenteric artery

Answer: (A)

The diaphragmatic crura are the tendinous bands that anchor the diaphragm to the lumbar spine and form the posterior margins of the openings through the diaphragm. The aorta passes through the diaphragm at the aortic hiatus, which sits between the left and right crura. In this arrangement, the crura lie in front of the aorta, with the aorta passing posterior to them. The other vessels aren’t related to the crura in the same way: the IVC goes through the central tendon (caval opening) more anteriorly and to the right, the portal vein lies in the hepatoduodenal ligament, and the SMA arises from the aorta at higher level and travels anterior to the spine but doesn’t pass between the crura. So the diaphragmatic crura are anterior to the aorta.