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.
The valves act as a one way system to promote the flow of blood back to the heart. If they didn't exist then blood would clearly flow with gravity and away from the heart when you stand. However in my eyes it's not entirely clear what the sequence of events here. The two broad schools of thought are either the vein valves fail primarily allowing pressure to build up in the venous system or the vein wall dialates in a response to sustained elevations of venous pressure. There's a plethora of literature on this subject.