Superior Perspective of Bilateral Lateral Ventricles and Third Ventricle.  The dissection is oriented such that anterior at the top and the left side of brain is on the left. The retractors have split the interventricular septum and separated the two fornices to demonstrate the floor of the third ventricle. A small piece of the pineal gland, attached via the pineal stalk to the habenular and posterior commissures, is visible along the superoposterior aspect of the third ventricle. The thalamostriate vein can be seen coursing in the groove between the thalamus and caudate nucleus in the lateral aspect of the lateral ventricle before making a turn posteriorly beneath the fornix and joining the internal cerebral veins (hidden from view by the retractors). (Image courtesy of AL Rhoton, Jr.)