Illustration of the normal brain and meninges (left to right): the forebrain and layers of dura and arachnoid mater; inset of the skull, dura, arachnoid, and pia mater, as well as the subarachnoid and subdural spaces; sagittal section of the skull, dura mater, arachnoid mater, cerebrum, cerebellum, brainstem, foramen magnum, and spinal cord.