On Earth, blood flows down from a person’s brain back toward the heart thanks in part to gravity, but very little is known about how this flow happens without gravity’s effects. Many crew members report headaches and other neurological symptoms in space, which may be related to the absence of gravity acting on blood flowing through the veins. Drain Brain uses a special neck collar to measure blood flow from the brain, to help researchers understand which physical processes in the body can compensate for the lack of gravity to ensure blood flows properly.
It will be interesting to learn what the Drain Brain study teaches us about venous return and the long terms affects of zero gravity. It is absurd to claim that slowed venous drainage does not matter to brain and eye health.
Here's to rocket scientists! Here's to Samantha Cristoforetti! You can follow her on twitter @AstroSamantha Here's to Dr. Zamboni!