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.
Holding the test tube of CSF against a white, printed page, the CSF should be as clear as a similar test tube filled with water. Normal CSF has very few WBCs (0â8/mm3). In the presence of an inflammatory response, WBCs increase. Normally, there are no RBCs or nearly none (<1 RBC/mm3). While a traumatic lumbar puncture (bloody tap) can result in RBCs being present in the CSF, the blood will progressively clear with each tube of CSF withdrawn. By the third tube, the CSF should be nearly clear, even with a bloody tap. CSF is normally sterile.