Fig. 3

Effect of arterial pulsation in horizontal and upright posture. During the cardiac cycle, the cranial arterial inflow \(Q_{a}\) (source [9]) leads to fluctuations in cranial arterial volume, \(\Delta V_{a}\). Compensating craniospinal flows of CSF (\(Q_{CSF}\)) and venous blood (\(Q_{v}\)), craniospinal CSF distribution (\(\Delta V^{c}\) versus \(\Delta V^{s}\)), and the corresponding cranial and spinal CSF pressures (\(p_{CSF}^{c}\) and \(p_{CSF}^{s}\), respectively) are shown for horizontal and upright posture. The corresponding measured CSF flow in supine position [9] is shown as dashed line. The flow rates are positive in the directions indicated in (Fig. 1)