The semitendinosus is innervated by what nerve?

The semitendinosus is innervated by what nerve?

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

Answer: (A)

The semitendinosus is one of the hamstring muscles in the posterior thigh, so its motor supply comes from the tibial division of the sciatic nerve. The sciatic nerve splits into a tibial division and a common fibular division; the tibial division innervates the long head of the biceps femoris, semitendinosus, and semimembranosus, whereas the short head of the biceps femoris is supplied by the common fibular division. That makes the tibial division the correct innervation for the semitendinosus. In contrast, the femoral nerve mainly innervates the anterior thigh muscles, and the obturator nerve supplies most of the medial thigh adductors, so they do not innervate the semitendinosus.

The semitendinosus is one of the hamstring muscles in the posterior thigh, so its motor supply comes from the tibial division of the sciatic nerve. The sciatic nerve splits into a tibial division and a common fibular division; the tibial division innervates the long head of the biceps femoris, semitendinosus, and semimembranosus, whereas the short head of the biceps femoris is supplied by the common fibular division. That makes the tibial division the correct innervation for the semitendinosus. In contrast, the femoral nerve mainly innervates the anterior thigh muscles, and the obturator nerve supplies most of the medial thigh adductors, so they do not innervate the semitendinosus.