After the Russian Revolution of 1917, Georgia declared independence in 1918, but the democratic Republic of Georgia, ruled by a social-democratic government, was invaded by the Red Army in 1921, a few days after it was recognized by European states.
And.. The Semilunar Valves prevent the back flow of the blood from the arteries to the ventricles. Explain what happens to tissues, such as the heart, or the brain, if oxygenated blood is not delivered in a timely manner. The tissue of the organ starts to die.
The point is that not all of your cells die quickly without oxygen. In surgeries they cut off blood supplies for up to hours and tissues don't die. Your brain is really what needs the oxygen. It has a huge metabolic requirement, and it needs a constant supply of oxygen for cellular respiration.