Which nerve innervates the piriformis?

Which nerve innervates the piriformis?

• A. nerve to piriformis
• B. superior gluteal nerve
• C. inferior gluteal nerve
• D. obturator nerve

Answer: (A)

The piriformis is supplied by a dedicated branch from the sacral plexus called the nerve to the piriformis. This nerve typically arises from ventral rami S1–S2 and travels directly to the deep surface of the piriformis to provide its motor innervation. That specific nerve is named for the muscle it innervates, which is why it’s the best answer. The other nerves have different targets: the superior gluteal nerve goes to gluteus medius, gluteus minimus, and tensor fasciae latae; the inferior gluteal nerve goes to gluteus maximus; and the obturator nerve mainly supplies medial thigh muscles (adductors) and does not innervate the piriformis.

The piriformis is supplied by a dedicated branch from the sacral plexus called the nerve to the piriformis. This nerve typically arises from ventral rami S1–S2 and travels directly to the deep surface of the piriformis to provide its motor innervation. That specific nerve is named for the muscle it innervates, which is why it’s the best answer.

The other nerves have different targets: the superior gluteal nerve goes to gluteus medius, gluteus minimus, and tensor fasciae latae; the inferior gluteal nerve goes to gluteus maximus; and the obturator nerve mainly supplies medial thigh muscles (adductors) and does not innervate the piriformis.