During normal development of the gut, the midgut loop undergoes rotation around the axis of the superior mesenteric artery. The correct description of this rotation is:

• A 270 degrees counterclockwise in total ✓
• B 90 degrees clockwise before return to the abdomen, then 180 degrees counterclockwise after return
• C 270 degrees clockwise in total
• D 180 degrees counterclockwise only

Explanation

The midgut loop rotates approximately 270 degrees counterclockwise (as viewed from the embryo's front) around the superior mesenteric artery: roughly 90 degrees during herniation into the umbilical cord and a further 180 degrees as it returns to the abdominal cavity. Clockwise or reversed rotation produces malrotation with volvulus risk, since the duodenojejunal junction and caecum end up mispositioned.

Reference: Langman's Medical Embryology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.