Describe the route that blood takes through the heart and body. Explain the structure of the blood vessels involved and why their structures are different.
The heart is a muscular pump that is constantly pumping blood through the body. The heart is essential for all life and pumps the equivalent of 14,000 litres of blood a day.
The blood starts its route at the aorta, where oxygenated blood exits the heart to be delivered to the body at high pressures. The blood is pumped all around the body where it delivery oxygenated blood to major organs, and collects waste products like CO2.
The blood enters the right side of the heart through two veins: The superior vena cava and the inferior vena cava. The Superior Vena Cava collects the blood from the upper half of the body, while the Inferior Vena Cava collects the blood from the lower half of the body. The blood then leaves the Superior and the Inferior Vena Cava and enters the right atrium.
When the Right Atrium contracts, the deoxygenated blood goes through the tricuspid valve and into the right ventricle. When the Right Ventricle contracts, blood is pumped through the pulmonary valve, into the pulmonary artery and into the lungs where it picks up oxygen.
This oxygenation stage happens because blood returning from the body is relatively poor in oxygen or deoxygenated. The blood needs to be full of oxygen before being returned to the body to be used. So the right side of the heart pumps blood to the lungs first to pick up oxygen before going to the left side of the heart where it is returned to the body full of oxygen or oxygenated.
The blood now returns to the heart from the lungs by way of the pulmonary veins and goes into the left atrium. When the Left Atrium contracts, blood travels through the mitral valve and into the left ventricle. The Left Ventricle is a very important chamber that pumps blood through the aortic valve and into the aorta. The aorta is the main artery of the body. It receives all the blood that the heart has pumped out and distributes it to the rest of the body. The Left Ventricle has a thicker