Which of the following area lies immediately lateral to the anterior perforating substance?: (A) Uncus, (B) Orbital gyrus, (C) Optic Chiasma, (D) Limen Insulae
Answer is D. Anterior perforating substance is an irregularly quadrilateral area in front of the optic tract and behind the olfactory trigone, from which it is separated by the fissure prima; medially and in front, it is continuous with the subcallosal gyrus; it is bounded laterally by Limen insulae of the olfactory tract and is continued into the uncus.