WHERE IS CEREBROSPINAL FLUID ABSORBED?

In most textbooks of physiology and many of anatomy it is stated as an accepted fact that cerebrospinal fluid passes from the subarachnoid space into the great venous sinuses through the pacchionian granulations. This statement was based on the results of injections of prussian blue suspensions into the spinal canal of cadavers by Key and Retzius. The color was found in the superior longitudinal sinuses and could be seen to pass through the pacchionian granules. But the observations were valueless in physiologic interpretations because cadavers instead of living animals were used and because the pressures used in the injections were far beyond any possible normal figures. It has since been repeatedly demonstrated that under normal conditions granules of prussian blue never pass through the pacchionian bodies.

Moreover, the hypothesis that cerebrospinal fluid is absorbed by the pacchionian granulations is instantly shattered by the fact that these structures are acquisitions only