Lesser sac
Abdominal cavity

The lesser sac, also known as the omental bursa, is a part of the peritoneal cavity that is formed by the lesser and greater omentum. Usually found in mammals, it is connected with the greater sac via the omental foramen or Foramen of Winslow. In mammals, it is common for the lesser sac to contain considerable amounts of fat.
01Anatomic margins
- Anterior margin
- listed from the top-to-bottom margin: Caudate lobe of the liver, lesser omentum, stomach, gastrocolic ligament
- Lateral margin
- listed from the most anterior to the most posterior margin: Gastrosplenic ligament, spleen, Lienorenal ligament
- Posterior margin
- Left kidney and adrenal gland, pancreas
- Inferior margin
- Greater omentum
- Superior margin
- Liver
If any of the marginal structures rupture their contents could leak into the lesser sac. If the stomach were to rupture on its anterior side though the leak would collect in the greater sac.
The lesser sac is formed during embryogenesis from an infolding of the greater omentum. The open end of the infolding, known as the omental foramen is usually close to the stomach.
Sources and credits
This article is adapted from the Wikipedia article “Lesser sac”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Gray1035.png by Henry Vandyke Carter, Public domain
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.