Which opening connects the greater and lesser peritoneal sacs?

• A. Foramen of Morgagni
• B. Epiploic foramen
• C. Foramen of Magendie
• D. Foramen of Bochdalek

Answer: (B)

The opening that connects the greater and lesser peritoneal sacs is the epiploic foramen (foramen of Winslow). This natural passage links the main peritoneal cavity with the omental (lesser) sac, which lies behind the stomach. Boundaries include the hepatoduodenal ligament with the portal triad anteriorly, the inferior vena cava and right crus of the diaphragm posteriorly, the caudate lobe of the liver superiorly, and the superior part of the duodenum and stomach inferiorly. That single opening is why it serves as the connection between the two sacs. The other openings listed are a congenital diaphragmatic defect (foramen of Morgagni or Bochdalek) or a brain ventricle outlet (foramen of Magendie), none of which connect the peritoneal spaces.