The arteries of the pituitary stalk and gland were described using our results as well as data obtained from the literature. There were three types of vessels to the pituitary from above: the superior hypophyseal artery originating from the internal carotid artery, the infundibular artery originating from the posterior communicating artery, and the prechiasmal artery from the ophthalmic artery. There were also three arteries from the cavernous carotid artery; the inferior hypophyseal artery, the capsular artery, and the artery of the inferior cavernous sinus. These arteries were anastomosed each other, making the rich vascular networks, called the "circuminfundibular anastomosis" around the pituitary stalk, and the "inferior hypophyseal arterial circle (or inferior capsular arterial rete)" in the base of the pituitary.