A horseshoe kidney, formed by fusion of the lower poles of both kidneys during their ascent, typically comes to lie at the level of the lower lumbar vertebrae because its ascent is arrested by which structure?
- A Root of the inferior mesenteric artery ✓
- B Root of the superior mesenteric artery
- C Left renal vein crossing the midline
- D Median arcuate ligament of the diaphragm
Correct answer: A. Root of the inferior mesenteric artery
Explanation
During normal ascent from the pelvis, kidneys pass the arterial forks of the iliac vessels and then the mesenteric arteries. In horseshoe kidney the fused lower pole becomes hooked under the origin of the inferior mesenteric artery from the aorta at about the L3 level, so the kidney remains low in the abdomen. The superior mesenteric artery lies far higher at L1 and does not arrest ascent.
Reference: Langman's Medical Embryology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.