the heart

the heart

1. superior/inferior vena cava deliver deox blood to right atrium through the semilunar valves to prevent back flow of blood back into the veins

   • when filled with blood thin atrium walls contract due to the low pressure and forces the blood into the right ventricle through the tricuspid valve (AV) as pressure is high in the atrium and to separate the atrium and ventricle and to prevent back flow of blood into the atrium
     • tough tendinous cords prevent valves from turning inside out due to the pressure when ventricles contract
       • when ventricles contract blood flows to the pulmonary artery through the SL valve, the blood collects O2 from the lungs and return throughout the pulmonary vein
         • blood flows at low pressure into the left atrium which contracts forcing blood into the left ventricle through the bicuspid valve
           • the thick muscular wall in the left ventricle contracts building pressure allowing blood to flow to the rest of the body through the aortic valve preventing back flow into the ventricle