The cerebral aqueduct (aqueduct of Sylvius) connects which ventricles?

• A. Lateral ventricles and third ventricle
• B. Fourth ventricle and subarachnoid space
• C. Third ventricle and lateral ventricle
• D. The third ventricle and the fourth ventricle

Answer: (D)

The cerebral aqueduct is the narrow canal that carries CSF from the third ventricle down into the fourth ventricle. From the lateral ventricles, CSF flows through the foramina of Monro into the third ventricle, then passes through the aqueduct of Sylvius to reach the fourth ventricle, and finally exits into the subarachnoid space via the foramina of Luschka and Magendie. So the aqueduct specifically connects the third ventricle with the fourth ventricle.