The Vascularization of the Rat Pineal Organ

Abstract

Publisher Summary From the angioarchitectonics, this chapter shows that the rat pineal is a densely and uniformly vascularized organ with a separate arterial supply. The venous outflow is directly in the great cerebral vein where also the median parts of the occipital poles of the hemispheres drain with veins, the appearance of which indicate the possibility of a large blood flow. In view of this and of the immediate drainage in the overlying sinus confluens, the hypothesis that backflow might take place in the great cerebral vein, eventually reaching the choroid plexus, does not seem feasible. The vascular system of the rat pineal organ was studied with various injection techniques. From the observations done with the light microscope and SEM, it was concluded that there is an independent arterial supply consisting of up to four branches of the posterior cerebral artery. The capillary network is at least as dense as in the cerebral cortex, and the venous drainage consists of 12-16 short veins, all draining in the great cerebral vein, and thereafter, via the confluens sinuum immediately in the systematic venous circulation.