Which nerve innervates semitendinosus?

Which nerve innervates semitendinosus?

• A. Tibial division of sciatic nerve
• B. Common fibular division of sciatic nerve
• C. Femoral nerve
• D. Obturator nerve

Answer: (A)

Semitendinosus is a hamstring muscle of the posterior thigh that helps flex the knee and extend the hip. It is innervated by the tibial division of the sciatic nerve, which supplies the other posterior thigh muscles as well. The common fibular division of the sciatic nerve sends motor fibers to the short head of the biceps femoris and portions of the leg, not to semitendinosus. The femoral nerve innervates the anterior thigh muscles, and the obturator nerve supplies most of the medial thigh muscles, neither of which innervates semitendinosus. So the tibial division of the sciatic nerve is the correct innervation.

Semitendinosus is a hamstring muscle of the posterior thigh that helps flex the knee and extend the hip. It is innervated by the tibial division of the sciatic nerve, which supplies the other posterior thigh muscles as well. The common fibular division of the sciatic nerve sends motor fibers to the short head of the biceps femoris and portions of the leg, not to semitendinosus. The femoral nerve innervates the anterior thigh muscles, and the obturator nerve supplies most of the medial thigh muscles, neither of which innervates semitendinosus. So the tibial division of the sciatic nerve is the correct innervation.