Collateral Branches of Intercostal Nerves (Left)

Description

The collateral branches arise from the intercostal nerves early in their course. These collateral branches arise medial to the angles of the ribs. It courses along the intercostal space, following the superior border of the rib below and between the internal and innermost intercostal muscles. The collateral branches are accompanied by a collateral artery and vein, where the vein sits closest to the rib below, the artery above and the nerve most superior in the arrangement. The collateral branches aid in supplying the intercostal muscles and parietal pleural of the lungs.