A NEW Ballot Drop Box has been installed by the County near the south mid-parking lot entrance to the Convention Center. You may drop your completed ballots inside the sleeve and envelope into the ballot box and the County
Each heart valve has two important functions: To open correctly so that blood can empty from the chamber. To close properly so that blood cannot flow the wrong way. When the valves and chambers fail to move blood properly, symptoms may eventually develop and may require critically important treatment. Learn more about the roles of your heart valves.
There is a problem when the valve that controls what blood is good and what blood is used, no longer is strong enough to control this flow. Heart valves get damaged or simply wear out. I think you are asking what causes blood to flow in the wrong direction. My guess is that it would be a faulty heart valve.