The third large opening in the diaphragm is the caval opening, through which the inferior vena cava passes from the abdominal cavity to the thoracic cavity (Fig. 4.143) at approximately vertebra TVIII in the central tendinous part of the diaphragm.
Accompanying the inferior vena cava through the caval opening is the right phrenic nerve.
The left phrenic nerve passes through the muscular part of the diaphragm just anterior to the central tendon on the left side.