Relationship of the diaphragm to the inferior vena cava in human embryos and fetuses.

The attachment of the inferior vena cava to the diaphragm is compared with that of the oesophagus and the aorta. The development of this attachment is described in human embryos and fetuses. In older fetuses the attached border of the diaphragm splits into several layers at its junction with the inferior vena cava. The insertion of the right crus of the diaphragm into the posterior wall of the inferior vena cava is thought to have physiological significance. The left phrenic nerve supplies the left half of the diaphragm and the left component of the right crus. The right phrenic nerve supplies the right half of the diaphragm including the right component of the right crus.