Which nerve passes directly inferior to the piriformis?

• A. Femoral nerve
• B. Sciatic nerve
• C. Obturator nerve
• D. Superior gluteal nerve

Answer: (B)

In the gluteal region, the piriformis serves as a landmark for the pathways of several nerves as they exit the pelvis. The sciatic nerve, the largest peripheral nerve, typically emerges from the pelvis through the greater sciatic foramen and runs directly inferior to the piriformis before descending down the posterior thigh. This inferior relationship is the classic course used to distinguish the sciatic nerve from the other nerves in this area. By contrast, the superior gluteal nerve exits the pelvis above the piriformis to supply the gluteal muscles, while the obturator nerve travels medially through the obturator canal, and the femoral nerve runs anteriorly under the inguinal ligament into the thigh, not in the same gluteal path.