- Divisions
- Lesser Sac (Omental Bursa): Posterior to stomach. Site of fluid accumulation in posterior gastric ulcer perforation or pancreatic pathology.
- Epiploic Foramen (Winslow): Connects Greater/Lesser sacs.
- Boundaries: Portal Triad (anterior), IVC (posterior).
- Pringle Maneuver: Clamp hepatoduodenal ligament here to stop liver bleeding.
- Gravity-Dependent Spaces (Fluid Accumulation)
- Hepatorenal Recess (Morison’s Pouch): Most dependent space in supine pt. First site of free fluid in trauma (FAST exam).
- Rectouterine Pouch (Pouch of Douglas): Most dependent space in standing/sitting female. Site of ectopic rupture blood/pus.
- Spread of Infection
- Right Paracolic Gutter: Wide/open. Facilitates spread of appendicitis to liver (subphrenic abscess).
- Left Paracolic Gutter: Blocked by phrenicocolic ligament. Limits spread to LUQ.
- Pathology Buzzwords
- Pneumoperitoneum: Perforated viscus → Air under diaphragm on upright CXR.
- Peritonitis: Rebound tenderness, rigidity (“acute abdomen”).