Thoracic nerves

The thoracic nerves are the spinal nerves emerging from the thoracic vertebrae.

Anterior divisions

 * The intercostal nerves come from thoracic nerves T1-T11, and run between the ribs ("costae"). At T2 and T3, it further branches into the intercostobrachial nerve.


 * The subcostal nerve comes from nerve T12, and runs below the twelfth rib.

Posterior divisions
The medial branches (ramus medialis; internal branch) of the posterior divisions of the upper six thoracic nerves run between the Semispinalis dorsi and Multifidus, which they supply; they then pierce the Rhomboidei and Trapezius, and reach the skin by the sides of the spinous processes.

The medial branches of the lower six are distributed chiefly to the Multifidus and Longissimus dorsi, occasionally they give off filaments to the skin near the middle line.