Abdominal Wall Nerves: Understanding Sensory & Motor Innervation

Innervation of the abdominal wall

The abdominal wall is supplied by sensory and motor nerves from the spinal cord. The sensory innervation is derived from the ventral rami of the lower six thoracic and the first lumbar nerves. The motor innervation is derived from the ventral rami of the lower six thoracic and the first lumbar nerves.

The main nerves that innervate the abdominal wall are:

- Iliohypogastric nerve (T12, L1): Supplies the skin and muscles of the upper and lateral abdominal wall.

- Ilioinguinal nerve (L1): Supplies the skin and muscles of the lower and medial abdominal wall.

- Genitofemoral nerve (L1, L2): Supplies the skin and muscles of the anterior thigh and the external genitalia.

- Lumbar nerves (T12, L1-L5): Supply the muscles of the abdominal wall, including the rectus abdominis, external oblique, internal oblique, and transverse abdominis muscles.

The abdominal wall is also innervated by sympathetic nerves from the lumbar and sacral spinal cord levels. These nerves control the blood vessels and sweat glands of the abdominal wall.