Numerous structures pass through or around the diaphragm (Fig. 4.143):
The aorta passes posterior to the diaphragm and anterior to the vertebral bodies at the lower level of vertebra TXII; it is between the two crura of the diaphragm and posterior to the median arcuate ligament, just to the left of midline.
Accompanying the aorta through the aortic hiatus is the thoracic duct and, sometimes, the azygos vein.