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 artery narrows and blood flow is reduced, thus decreasing the oxygen supply. Often a blood clot forms and blocks the artery, stopping the flow of blood. If the oxygen supply to the heart muscle is reduced, a heart attack can occur. If the oxygen supply to the brain is cut off, a stroke can occur.