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.
The function of the CSF includes cushioning and lubrication of the central nervous system, circulation of nutrients, and waste collection. Total CSF volume is 90-150 mL in adults and 10-60 ml in neonates. There is a constant turnover of about 14% of the volume per hour. About 300-500 mL of CSF are formed per 24 hours (0.35 mL per minute). CSF is obtained by lumbar puncture, with removal of fluid from the lumbar sac, located at the L3-4 or L4-5 interspace. At this level, the needle cannot injure the spinal cord, which in adults ends at L1.