Quick Facts
Location: Posterior intercostal space.
Drainage: Posterolateral intercostal spaces, posterolateral mammary gland, parietal pleura, vertebrae, and muscles of the back proper (deep muscles of the back).
Direction of Flow: Thoracic duct or right lymphatic duct.
Description: (Location & Drainage)
The intercostal lymph nodes are located in the posterior aspect of the intercostal spaces, near the head and necks of the ribs. There can be up to six nodes in each intercostal space, but usually there are only one to three.
The afferent vessels of the intercostal lymph nodes collect lymph from the posterolateral aspects of the intercostal spaces and mammary glands. Additionally, they receive lymph from the posterior costal pleura, the vertebrae, and the deep muscles of the back (muscles of the back proper).
Efferent vessels of the first and second intercostal spaces unite forming an intercostal trunk, which drain into the right lymphatic or thoracic duct on the right and left side of the body, respectively. Efferent vessels of the fourth to seventh or eighth intercostal nodes drain into the thoracic duct. The efferent vessels of the lower intercostal nodes form a common trunk, intercalated by the prevertebral lymph nodes. The trunk descends and forms a U-shaped loop before draining into the thoracic duct or cisterna chyli.
