The heart is a complex system, with an enormous capacity for work. Think about it. Every day, every hour, every minute, pretty much every second the heart contracts and sends oxygenated blood to your working muscle and carries CO2 and waste products away.
Blood gets oxygenated in the lungs. The lungs have such a huge area that oxygen diffuses into the blood, while CO2 diffuses out.
Image borrowed from The british heart foundation
The oxygenated blood now enters the heart trough the pulmonary vein and into the left atrium.
From the left atrium it enters the left ventricle. When the heart contracts, the valves close down to stop the blood flow from reversing.
With great force the blood is then pumped out into the Aorta, where it separates into 2 different main arteries. One for the body and one for the head.
The arteries then branches out until he blood reaches the working tissue. Here the large vessels have now been replaced by tiny capillaries that make diffusion of oxygen from the blood to the working tissue a lot easier.
The blood have now released most of its oxygen and have taken up quit a lot of CO2. It now flows trough the veins back to the heart. It enters the right atrium and then the right ventricle, where it is pumped to the lungs. Here the blood releases the CO2 and binds new O2 and the cycle is complete
Ingen kommentarer:
Send en kommentar