Lateral sulcus Lateral sulcus The lateral sulcus (also called Sylvian fissure or lateral fissure) is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe. The insular cortex lies deep within the lateral sulcus. The lateral sulcus divides both the frontal lobe and parietal lobe above from the temporal lobe below. It is in both hemispheres of the brain. The lateral sulcus is one of the earliest-developing sulci of the human brain. It first appears around the fourteenth gestational week. The
Choroidal fissure ganglion cells in the sensory retina) do not lie in the groove that is the choroid fissure, they do extend through the portions of the optic stalk that form the walls of the fissure. These axons will form the optic nerve. The fissure is eventually sealed when the lips of the optic cup, as well as the edges of the groove in the optic stalk, fuse. Failure of this fissure to close results in coloboma iridis. Choroidal fissure The choroid is the middle, vascular coat of the eye which resides between the sclera and the retina. Early in development the