Answer
The cerebrospinal fluid circulates through the brain and into the spinal cord. The propulsive power that maintains the circulation derives from the following sources:
The hydrostatic pressure of the blood (BP)
The beating of the cilia of ependymal cells
The rhythmic pulsations of the brain generated by the heart beat,
Under this propulsion the CSF follows the following circulatory path.
From the lateral ventricles, it flows through the interventricular foramina into the third ventricle.
The third ventricle adds more CSF to that coming from the lateral ventricles. From the third ventricle the CSF then flows through the cerebral aqueduct to the fourth ventricle. The fourth ventricle also adds more CSF to that coming from the third ventricle.
Work Step by Step
CSF flows out of the fourth ventricle through the two lateral and one median apertures; it enters the subarachnoid spaces to bathe the external surfaces of the brain. Some CSF also passes from the fourth ventricle into the central canal of the spinal cord. CSF is absorbed by arachnoid villi into the venous blood of the dural sinuses
