A probe through aqueduct of Sylvius (connecting 3rd and fourth ventricle)
Base of brain showing vessels and exit of cranial nerves
A probe through foramen of magendie (connects fourth ventricle and subarachnoid space for CSF to circulate) (connecting 3rd and fourth ventricle)
Floor of fourth ventricle
Grey and white matter of cortex
Sagittal section
Surface of cortex