Answer: Triscupid valve
Explanation: The triscupid valve between the right atrium and the right ventricle opens and allows oxygenated blood to flow through. Pressure from blood filled atrium and electrical impulse transmitted by the sinoatrial nodes allows the triscupid valve to open, pass blood to the ventricles and immediately shuts itself and close the atrium when its empty, in a coordinated manner. Triscupid valve shuts to prevent oxygenated blood from flowing back to the right atrium after it has passed through.