The inferior frontal gyrus is one of four such gyri in the frontal lobe. These series of convolutions called gyri (singular, gyrus) are perhaps the most distinguishing feature of the external cerebral surface. Between them are grooves of varying depth called sulci (singular, sulcum) or fissures. The frontal lobe is crossed over by three sulci, which divide the frontal lobe into four gyri. The three Continue Scrolling To Read More Below...