Which nerve innervates the vastus lateralis?

Which nerve innervates the vastus lateralis?

• A. Femoral nerve
• B. Obturator nerve
• C. Tibial nerve
• D. Sciatic nerve

Answer: (A)

The key idea is that the vastus lateralis is one of the quadriceps muscles in the anterior compartment of the thigh, and these muscles are innervated by the femoral nerve. The femoral nerve, arising from lumbar nerve roots L2–L4, travels into the thigh and provides motor innervation to all four quadriceps muscles, including the vastus lateralis, enabling knee extension. It also carries sensory fibers to the anterior thigh and to the medial leg via the saphenous branch. Obturator nerve supplies the medial thigh muscles (adductors), not the quadriceps. The tibial and sciatic nerves primarily innervate the posterior compartments of the thigh and leg and are not responsible for the motor innervation of the quadriceps. Therefore, the nerve that innervates the vastus lateralis is the femoral nerve.

The key idea is that the vastus lateralis is one of the quadriceps muscles in the anterior compartment of the thigh, and these muscles are innervated by the femoral nerve. The femoral nerve, arising from lumbar nerve roots L2–L4, travels into the thigh and provides motor innervation to all four quadriceps muscles, including the vastus lateralis, enabling knee extension. It also carries sensory fibers to the anterior thigh and to the medial leg via the saphenous branch.

Obturator nerve supplies the medial thigh muscles (adductors), not the quadriceps. The tibial and sciatic nerves primarily innervate the posterior compartments of the thigh and leg and are not responsible for the motor innervation of the quadriceps. Therefore, the nerve that innervates the vastus lateralis is the femoral nerve.