The human pineal gland: relationships with surrounding structures and blood supply.

After a short overview of the history of our knowledge of the pineal gland, its anatomy and its function, this work is primarily devoted to the relationships of the pineal gland to the nerve structures which delineate the pineal region. The complex surrounding blood vessels located in the quadrigeminal cistern are described with a special focus on the numerous venous trunks. Finally, the pineal blood supply is studied in three steps: (1) The arterial supply obtained through several groups of pineal arteries stemming mainly from the medial posterior choroidal arteries; (2) The venous drainage by the lateral pineal veins flowing, in most cases, into the cerebral vein of Galen; (3) The intrapineal vascular architecture with specific features concerning the central part of the gland highly vascularized by large sinusoid capillaries and its peripheral part poorly vascularized by small and fine blood vessels.