In which structure would you find the arachnoid villi?

Arachnoid villi are specialized structures located on the surface of the brain, primarily extending into the dural sinuses. They serve a crucial function in the reabsorption of cerebrospinal fluid (CSF) into the venous system. It is within the subarachnoid space that the arachnoid villi are found, protruding through the arachnoid mater and into the venous sinuses to facilitate this fluid exchange.

Understanding their location within the subarachnoid space is vital, as this is where CSF circulates around the brain and spinal cord, providing cushioning and nutrient transport. The presence of arachnoid villi in this area allows for effective drainage of the CSF back into the bloodstream, helping to maintain proper intracranial pressure and overall brain health.

While the dural sinuses are adjacent to the space where the villi reside, they are not the primary structure containing arachnoid villi, making the subarachnoid space the correct choice. The other options, such as the cerebral aqueduct and lateral ventricles, do not contain arachnoid villi, as these areas are involved in the circulation and production of CSF rather than its absorption