Each day 500 ml of Cerebrospinal fluid (CSF) is secreted mostly by the choroids plexus within the lateral and with the 3rd and 4th ventricles. Very little appears to change the production rate of CSF other than quite markedly raised intracra-nial pressure which reduces it. The CSF flows from the lateral ventricles through the foramina of Munro into the 3rd ventricle and thence down the aqueduct of Sylvius situated in the midbrain and upper pons. Once in the 4th ventricle, a very small amount passes down the central canal of the spinal cord but the vast majority flows out through the lateral foramina of Luschka and the central foramen of Magendie. Thereafter the CSF can flow down the subarachnoid space in the spine or pass upwards; eventually all CSF passes upward in the subarachnoid spaces around the midbrain and thence over the cerebral hemispheres and particularly to the para-sagittal areas. It is reabsorbed into the blood stream through the arachnoid villi which protrude into the great venous sinuses, the superior sagittal sinus in particular.
Was this article helpful?