Intercostal nerves

The intercostal nerves are the anterior rami of the thoracic spinal nerves (T1-T11), running along the intercostal spaces. They provide motor innervation to the intercostal and abdominal muscles and sensory innervation to the skin of the thoracic wall and upper abdomen. Unlike other spinal nerves, they do not form a plexus, maintaining a segmental distribution. The anterior ramus of the twelfth thoracic nerve (T12) travels beneath the 12th rib and is classified as the subcostal nerve, rather than an intercostal nerve.

For detailed information on the anatomical course of the intercostal nerves and their branches, refer to the description of the anterior rami of thoracic nerves.