Patterns of the Cranial Venous System from the Comparative Anatomy in Vertebrates. Part II.The Lateral-Ventral Venous System.

Comparing the adult submammalian brain with the human embryonic brain, some patterns of venous drainage are quite similar. The veins lying on the lateral surface of the brain in submammals resemble those of the human embryo. In addition, the new longitudinal venous anastomosis ventral to the brain vesicles occurring late in human embryonic development seems to be similar to the late appearance of the basal vein and the ventral brain stem venous plexus found in adult mammals including man. The evolution of the new structures of the brain vesicles throughout the vertebrate series may have an induction role on the appearance of the cranial venous system. This part of the article series focuses on the evolution of the lateral-ventral venous system of the five brain vesicles. Nevertheless, the limitation of this article is due in part to the paucity of circumstantial papers and different names used for the veins.