 |
The development of the adult venous system occurs via a complex series of shunts and involutions. Additionally, the development of the liver from the mesenchymal cells of the septum transversum imposes vascular changes in the process of forming the hepatic sinusoids.
The following figure represents the paired venous drainage into the primitive heart.
| |
The changes in the venous system all have the common goal of introducing right-sided asymmetry in the adult system. The circulatory changes can be considered as four discrete events, shown here.
As a result of the three shunts, the right horn of the sinus venosus becomes enlarged in relation to the left side. The shunts also result in involutions and changes in certain vessels. These are shown below.
