Cerebellopontine angle
The cerebellopontine angle (CPA) (Latin: angulus cerebellopontinus) is located between the cerebellum and the pons.This fissure is made when the cerebellum folds over to the pons, creating a sharply defined angle between them.The pia mater follows the outline of the fissure and the arachnoid mater continues across the divide so that the subarachnoid space is dilated at this area, forming the cerebellopontine angle cistern.[citation needed] The anterior inferior cerebellar artery (AICA) is the principal vessel of the cerebellopontine angle.[citation needed] Tumours can arise in the cerebellopontine angle.