Left temporal lobe (superior view). One can think of the medial temporal lobe as a "ladder" with the following "steps" going from medial to lateral: the parahippocampal gyrus, the dentate gyrus (so named because its surface is a series of tooth-like projections, caused by impressions of small transverse crossing vessels), the fimbria, and the hippocampus. The anteromedial part of the parahippocampal gyrus forms a "hook" or surface bulge known as the uncus. The uncus has an anterior and posterior surface and a group of small gyri. The apex of the uncus projects medially and is in close proximity to the oculomotor nerve and midbrain. Posteriorly there are several small gyri overlying the infolded head of the hippocampus: the uncinate gyrus, band of Giacomini, and intralimbic gyrus. The semianular sulcus separates the ambient gyrus superiorly from the semilunar gyrus. The uncal recess separates the hippocampus from the amygdala. The collateral eminence is a protuberance in the temporal horn of the lateral ventricle made by the collateral sulcus.  (Image courtesy of AL Rhoton, Jr.)