Cerebrospinal fluid circulation

The Cerebrospinal fluid (CSF) is actively secreted by choroid plexuses located in the lateral, third, and fourth ventricles as shown in figure. The Flow of CSF is from the lateral ventricles through the foramen of Munro into the third ventricle, and then throughout the aqueduct of Sylvius into the fourth ventricle. From here it drains via three orifices into the subarachnoid space. It equilibrates here with extracellular fluid in the perivascular spaces. Lastly it is dumped into the venous sinuses via the arachnoid villi.