five measurements were made : ( a ) the distance between the interpeduncular fissure and the aqueduct , ( b ) the distance from the anterior surface of the cerebral peduncles to the aqueduct , ( c ) the distance between the anterior surface of the pons midway between the mesencephalon and medulla to the fourth ventricular floor , ( d ) the shortest anteroposterior diameter of the medulla at the pontomedullary junction , and ( e ) the shortest anteroposterior diameter of the medulla at the medullospinal junction .
C0007793
cerebral peduncles
C0025462
mesencephalon