Atria is where all the blood from both side of the heart gather (top of the heart). The vessels
that enter the right atria is called the Superior vena cava and Inferior vena cava and the exit
vessels are called pulmonary arteries. The vessels that enter the left atria is called the
pulmonary vein and the exit vessels is called the aorta. Ventricles is located on the bottom of
the heart and this is where the heart contracts to push the blood to the right exit.
The blood will enter the right atria then it will be pumped down into the right ventricle this will
pass through the tricuspid valve. Then the ventricles will contract pumping the blood to the
pulmonary artery passing through the semilunar valve. The blood will undergo gas exchange in
the lungs picking up oxygen and dumping off carbon dioxide. Then the blood will travel to the
left atria through the pulmonary vein. The atria will contract pumping the blood to the left
ventricle passing through the mitral valve. Then the ventricle will contract pumping the blood to
the aortic arch passing through the semilunar valve.
Arteries has to be elastici