The internal oblique muscle is innervated by which nerves?

The internal oblique muscle is innervated by which nerves?

• A. Iliohypogastric nerve
• B. Ilioinguinal nerve
• C. Iliohypogastric nerve and ilioinguinal nerve
• D. Subcostal nerve

Answer: (C)

The main idea is that the internal oblique is innervated by nerves from the lumbar region that run with the abdominal wall layers. Specifically, the iliohypogastric and ilioinguinal nerves (both from the first lumbar nerve, L1) travel between the internal oblique and transversus abdominis and provide motor innervation to the internal oblique (as well as the transversus abdominis). This makes them the best single source listed for innervating the internal oblique. The subcostal nerve (T12) mainly supplies the external oblique, with only limited contribution to the internal oblique, and the thoracoabdominal nerves (T7–T11) also contribute, but the combination of iliohypogastric and ilioinguinal nerves directly reflects the primary L1 motor input to this muscle.

The main idea is that the internal oblique is innervated by nerves from the lumbar region that run with the abdominal wall layers. Specifically, the iliohypogastric and ilioinguinal nerves (both from the first lumbar nerve, L1) travel between the internal oblique and transversus abdominis and provide motor innervation to the internal oblique (as well as the transversus abdominis). This makes them the best single source listed for innervating the internal oblique. The subcostal nerve (T12) mainly supplies the external oblique, with only limited contribution to the internal oblique, and the thoracoabdominal nerves (T7–T11) also contribute, but the combination of iliohypogastric and ilioinguinal nerves directly reflects the primary L1 motor input to this muscle.