Which spinal levels contribute to the femoral and obturator nerves?

Which spinal levels contribute to the femoral and obturator nerves?

• A. L1–L2
• B. L2–L4
• C. L3–L5
• D. L4–L5

Answer: (B)

These two nerves come from the lumbar plexus, formed by the ventral rami of L2 through L4. The femoral nerve arises from the posterior divisions of L2–L4 and travels to the anterior thigh, while the obturator nerve comes from the anterior divisions of L2–L4 and passes through the obturator canal to innervate the medial thigh. L1 mainly contributes to other nerves (like iliohypogastric/ilioinguinal and genitofemoral), and L5 is not a primary contributor to these two nerves. So, the shared spinal levels are L2–L4.

These two nerves come from the lumbar plexus, formed by the ventral rami of L2 through L4. The femoral nerve arises from the posterior divisions of L2–L4 and travels to the anterior thigh, while the obturator nerve comes from the anterior divisions of L2–L4 and passes through the obturator canal to innervate the medial thigh. L1 mainly contributes to other nerves (like iliohypogastric/ilioinguinal and genitofemoral), and L5 is not a primary contributor to these two nerves. So, the shared spinal levels are L2–L4.