This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Obstruction to the flow of CSF at the aqueduct of Sylvius will most likely lead to enlargement of 
Select and explain. 
A. All of the ventricales, B. Only lateral ventrical, C. Only fouh ventrical, D. Both lateral and third ventricles
D: Both lateral and third ventricles
Answer: D: Both lateral and third ventricles 
Explanation: CSF formation - choroid plexuses of the lateral third, and fouh ventricles. Some also originate from the ependymal cells lining the ventricles and from the brain substance CSF Circulation - lateral ventricles - third Ventricle of Sylvius - IV ventricle of magendie and Luschka - subarachnoid space - absorption by arachnoid vill Therefore, obstruction at aqueduct of sylvius will lead to enlargement of both lateral and third ventricles.