When you plug your device into a charging socket or wall charger, the USB controller in your device talks to the USB controller attached to the socket/wall charger â or, if no controller is available, the device reads the voltage flowing across the four USB pins.
The volume of the ventricles is about 25 ml. CSF is produced at a rate of 0.2 - 0.7 ml per minute or 600-700 ml per day. The circulation of CSF is aided by the pulsations of the choroid plexus and by the motion of the cilia of ependymal cells.
Most of the CSF is secreted by the choroid plexus of the four ventricles. This accounts for about two-thirds of the 500 to 700 milliliters of CSF that are produced in a day. The remaining quantities of CSF are secreted by the ependymal surfaces of the ventricles and the arachnoid mater.