Course and relations Each intercostal artery is accompanied by the corresponding (i.e. ipsilateral)
subcostal vein and
nerve.'
Each passes along the lower border of the 12th rib.' Before entering the
anterior abdominal wall, each runs laterally upon the anterior surface of the
lumbar fascia (and thus also anterior to the underlying
quadratus lumborum muscle which the lumbar fascia envelops) posterior to the ipsilateral kidney.'
It then pierces the posterior aponeurosis of the transversus abdominis, thus entering the anterior abdominal wall to course in between the abdominal internal oblique muscle and transverse abdominal muscle (the neurovascular plane of the anterior abdominal wall).'
Branches Each subcostal artery gives off a posterior branch which has a similar distribution to the
posterior ramus of an intercostal artery.''''''
Anastomoses It
anastomoses with the
superior epigastric,
lower intercostal, and
lumbar arteries.'''''' ==References==