Corpus: Subcostal nerve

The subcostal nerve is the anterior branch of the 12th thoracic nerve and is the continuation of the series of intercostal nerves.

The subcostal nerve is larger than the intercostal nerves. It runs ventrally along the lower edge of the 12th rib. It communicates with the first lumbar nerve and with the lumbar plexus and passes underneath the lateral lumbocostal artery.

Its further course takes it past the front of the quadratus lumborum muscle. Finally, it pierces the transversus abdominis muscle and continues ventrally and medially between it and the obliquus internus abdominis muscle.

The subcostal nerve communicates with the iliohypogastric nerve from the lumbar plexus and gives off a branch to the pyramidal muscle. Its lateral cutaneous ramus supplies the lateral skin areas above the hip.