A, Anterior view of the cerebral hemispheres. The branches of the ACA cross the superior and anterior margins of the hemisphere to supply the adjacent part of the lateral convexity (arrows). These ACA branches exiting the interhemispheric fissure course deep to the venous lacunae and the cortical veins entering the superior sagittal sinus. B, The falx and right frontal lobe have been retracted to expose the A3s passing around the genu of the corpus callosum deep in the interhemispheric fissure. The A4s course above the anterior part of the callosal body. C, The cortical strip above the right cingulate sulcus has been removed, while preserving the ACA branches looping deep within the sulci on the medial surface of the hemisphere. These branches often course within a sulci along the superior margin to reach the lateral surface. D, Enlarged view of the branches of the ACA coursing deep within the cingulate sulcus. Some branches course deep within sulci along the superior margin of the hemisphere rather than looping over the upper edge of the superior margin to reach the lateral surface. (Images courtesy of AL Rhoton, Jr.)