healthy-Pumping Action
My littlest brother, being informed that we were half Scottish and half English, decided that his red blood was English and the blue blood he could see in his veins was Scottish. (He married a Welsh woman – goodness knows how he’ll explain it all to their baby…)Blood flowing from the lungs, where it has absorbed oxygen, is pumped via the heart around the body through arteries. These arteries are the motorways and A roads of the circulatory system. They divide up into smaller arteries, which are more like the B roads and which divide further into tiny capillaries that resemble the narrow country lanes that delve into the depths of the countryside (and usually contain a stray sheep or two that it’s impossible to get past when in a hurry). It is these capillaries that carry oxygenated blood to the tissues and organs, as they are able to penetrate into the furthest flung areas.
Meanwhile, capillaries carry nutrients that are absorbed from the intestinal tract into the main bloodstream, from whence they can be delivered to the organs and tissues that need them. Blood also passes through the liver, where it is filtered and cleansed.
Once the nutrients and oxygen contained in the blood have been delivered, the blood drains into small veins which combine into bigger veins and eventually returns to the heart and lungs to offload carbon dioxide and collect more oxygen. One circuit completed. And it’s no mean feat; there are many miles of blood vessels spread throughout our bodies. Your blood is doing constant marathons.
more:http://www.healthywaymagazine.com/issue27/04_circulatory_system.html