Blood Circulation (The Heart)
Blood enters the Right Atrium from the Superior Vena Cava (Vein from the top of
body) and the Inferior Vena Cava. (Vein from the lower part of body) The right
atrium contracts pushing the blood through the Tricuspid Valve into the Right
Ventricle where another contraction pushes the blood through the Pulmonary Valve
into the Pulmonary Artery that splits into the Right and Left Pulmonary Arteries
(They go to the right and left lungs). The lungs remove the CO2 from the blood
through the capillaries (These are porous to gases) and replace it with Oxygen. The
oxygenated blood returns to the Left Atrium of the Heart through the four Pulmonary
Veins. A contraction in the Left Atrium pushes the oxygenated blood through the
Bicuspid Valve into the Left Ventricle. The Left Ventricle then contracts to push the
blood into the Aorta for transport around the body.
1.Superior Vena Cava 2.Aortic Arch 3.Descending Aorta 4.Inferior Vena Cava
5.Aorta 6.Right Atrium 7.Right Ventricle 8.Left Atrium 9.Left Ventricle 10.Septum
11.Pulmonary Valve 12.Pulmonary Arteries 13.Pulmonary Veins 14.Mitral (Bicuspid)
Valve 15.Tricuspid Valve
Endocardium: The inner layer of the Heart.
Myocardium: The middle layer of the Heart. This is the thickest layer and is made up
of cardiac muscle.
Pericardium: The outer layer.