The document summarizes the anatomy and contents of various brain cisterns. It describes the locations and structures contained within several major cisterns, including:
1) The cisterna magna, which contains the cerebellar medullary veins and lower cranial nerves.
2) The interpeduncular cistern, which is divided by membranes and contains the basilar artery, posterior cerebral arteries, and cranial nerves 3 and 6.
3) The ambient cistern, which surrounds the midbrain and contains the posterior cerebral artery and cranial nerve 4.
4) The suprasellar/chiasmatic cistern, located above the pituitary fossa,