THE VIDEO DEMONSTRATES THE EXTERNAL FEATURES OF PONS AND THE FLOOR OF THE FOURTH VENTRICLE.
THE FLOOR OF FOURTH VENTRICLE IS ALSO KNOWN AS RHOMBOID FOSSA WHICH IS A DIAMOND SHAPED FLOOR, FORMED IN THE UPPER HALF BY THE POSTERIOR SURFACE OF PONS, AND IN THE LOWER HALF BY THE POSTERIOR SURFACE OF UPPER OPEN PART OF MEDULLA OBLONGATA.