Noun | 1. | sulcus - (anatomy) any of the narrow grooves in an organ or tissue especially those that mark the convolutions on the surface of the brain fissure - (anatomy) a long narrow slit or groove that divides an organ into lobes central sulcus, fissure of Rolando, Rolando's fissure, sulcus centralis - a brain fissure extending upward on the lateral surface of both hemispheres; separates the frontal and parietal lobes fissure of Sylvius, lateral cerebral sulcus, sulcus lateralis cerebri, Sylvian fissure - the deepest and most prominent of the cortical fissures; separates the frontal lobes and temporal lobes in both hemispheres parieto-occipital fissure, parieto-occipital sulcus - a sulcus near the posterior end of each hemisphere that separates the parietal lobes and the occipital lobes in both hemispheres calcarine fissure, calcarine sulcus - a sulcus in the mesial surface of the occipital lobe of the cerebrum anatomy, general anatomy - the branch of morphology that deals with the structure of animals |