Which nerve is primarily responsible for innervation of the transverse abdominis muscle?

Which nerve is primarily responsible for innervation of the transverse abdominis muscle?

• A. Subcostal nerve
• B. Iliohypogastric nerve
• C. Ilioinguinal nerve
• D. Genitofemoral nerve

Answer: (B)

The transverse abdominis is innervated by nerves that run with the lower abdominal wall, and among these, the iliohypogastric nerve provides direct motor input to this muscle. It arises from L1 and travels between the internal oblique and the transversus abdominis, giving branches that specifically innervate the transverse abdominis (along with the internal oblique). Because of this direct relationship and its primary role in supplying these muscles, the iliohypogastric nerve is the best answer. The subcostal nerve (T12) also contributes to the abdominal wall muscles, but it is not the principal motor nerve to the transverse abdominis in this context. The ilioinguinal nerve mainly handles sensation to the groin and parts of the lower abdomen, with only a lesser motor role here, and the genitofemoral nerve does not innervate the transverse abdominis.

The transverse abdominis is innervated by nerves that run with the lower abdominal wall, and among these, the iliohypogastric nerve provides direct motor input to this muscle. It arises from L1 and travels between the internal oblique and the transversus abdominis, giving branches that specifically innervate the transverse abdominis (along with the internal oblique). Because of this direct relationship and its primary role in supplying these muscles, the iliohypogastric nerve is the best answer. The subcostal nerve (T12) also contributes to the abdominal wall muscles, but it is not the principal motor nerve to the transverse abdominis in this context. The ilioinguinal nerve mainly handles sensation to the groin and parts of the lower abdomen, with only a lesser motor role here, and the genitofemoral nerve does not innervate the transverse abdominis.