How Does Csf Leave the Subarachnoid Space?

The CSF exits the subarachnoid space by diffusing through the walls of arachnoid granulations. The arachnoid granulations provide a valvular mechanism for the flow of CSF, which allows the inflow of CSF into the bloodstream without permitting the backflow of blood into the CSF.

How is CSF removed from the brain?

CSF flows into brain tissue and ISF effluxes from brain tissue into the CSF along perivascular spaces. The glymphatic system helps rid the brain of waste products. Such products are filtered through the arachnoid villi and removed by the venous circulation.

Where does the CSF drain into?

CSF is mainly secreted by the choroid plexus and, to a lesser extent, by the interstitial compartment. It circulates rostrocaudally inside the ventricles and drains into the cerebellomedullary cistern (cisterna magna) through the median aperture (foramen of Magendie) of the fourth ventricle.