The uncus is the hook-shaped front end of the parahippocampal gyrus, on the inner underside of each temporal lobe. A small groove, the rhinal sulcus, separates it from the tip (apex) of the temporal lobe. [1]
The 3D brain needs JavaScript. The text below still says where the uncus is and what it does.
Opens cut by a front (coronal) slice through the parahippocampal gyrus, which holds the uncus. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Lit: the whole parahippocampal gyrus, on both sides. The area is part of this gyrus; its exact border is not drawn. It is the front extremity of the parahippocampal gyrus. BodyParts3D has no uncus shape and draws the parahippocampal gyrus as one shape, so the whole gyrus is lit. [1][2]
It is the front end of the parahippocampal gyrus, separated from the apex of the temporal lobe by the rhinal sulcus. [1]
A band of the dentate gyrus, the band of Giacomini or tail of the dentate gyrus, crosses its underside. [1]
Although on the surface it is continuous with the parahippocampal gyrus, by its form it belongs to the rhinencephalon, the old smell brain. [1]
What it does
Part of the olfactory cortex on the temporal lobe covers the uncus: the lateral olfactory stria bends toward it, and the piriform cortex there receives the olfactory tract directly. [1][3][4]
Little has been written on what the uncus itself does; sources give it mainly as an anatomical landmark and as the site of part of the smell cortex. [1]
From the Latin uncus, “hook”; the term was coined by Félix Vicq d’Azyr (1748–1794). [1]
Size
The model has no shape for the uncus itself, so it is not measured here. The whole left parahippocampal gyrus that holds it measures about 49 mm front to back, 22 mm top to bottom and 21 mm side to side on this model (the box it fits in, not its volume). [2]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.