Figure 2.

Driving forces of cerebrospinal fluid (CSF) movement within the ventricles and subarachnoid spaces. The movement of CSF is convective and pulsatile. The two main driving forces of the pulsatile CSF movement are the cardiac-driven force and the respiratory-driven force. These forces influence the arterial blood and the venous blood differently, and thereby CSF movement to a different extent. (A) The cardiac-driven force causes a change in blood volume leading to pulsations that are transmitted directly or indirectly to the CSF. (B) The respiratory force consists of thoracic respiration and diaphragmatic respiration. Both types of respirations influence the CSF movement through the venous system, e.g., epidural venous plexus by changes in the intrathoracic pressure.