NBME Gross Anatomy High Yield Practice Test

The spread of ascitic fluid within the peritoneal cavity is shaped by peritoneal reflections and gutters. The left paracolic gutter runs near the left colic flexure and can convey fluid upward toward the subphrenic space, but a barrier formed by the phrenicocolic ligament blocks this ascent. This ligament extends from the left colic flexure to the diaphragm, creating a shelf that prevents fluid in the left paracolic gutter from moving into the left subphrenic (subdiaphragmatic) space. Thus it best limits the spread of ascitic fluid in that region. Other structures listed don’t form such a barrier relevant to the left paracolic gutter: the gastrohepatic ligament connects liver to stomach and isn’t a restraining shelf for left-gutter fluid; the hepatorenal ligament anchors liver to the kidney but doesn’t impede gutter spread; the phrenicopleural membrane separates pleural and peritoneal cavities and isn’t the peritoneal barrier in this context.