1)CSF is produced by the choroid plexus in the ventricles.

2)CSF flows from the lateral ventricles, through the interventricular foramen into the third ventricle, and then through the cerebral aqueduct into the fourth ventricle.

3)CSF in the fourth ventricle passes through the paired lateral apertures or the single median aperture, and into the subarachnoid space as well as the central canal of the spinal cord.

4)As the CSF flows through the subarachnoid space, it provides buoyancy to support the brain.

5)Excess CSF flows into the arachnoid villi, then drains into the dural venous sinuses. The greater pressure on the CSF in the subarachnoid space ensures that CSF moves into the dural venous sinuses without permitting venous blood to enter the subarachnoid space.

Review: Ch 15 brain