How Is The Circulation Of Our Blood Carried On?
In very simple language, the blood circulates due to the fact that the heart “pumps” it and the veins and arteries act at ‘pipes’ to carry it. The blood circulates to carry oxygen from the lungs and food material from digestion organs to the rest of the body. It also removes waste products from the tissues.
The pipes are two systems of hollow tubes. One is large and the other is small. Both are connected to the heart, the ‘pump’, but do not connect with each other. The smaller system of blood vessels goes from the heart to the lungs and back. The larger system goes from the heart to the various parts of the body. These tubes are named ‘arteries’, ‘veins’, and ‘capillaries’. Arteries remove blood away from the heart: the veins carry blood back to heart. The capillaries are tiny vessels for carrying blood from arteries to veins
The ‘pump’, the heart is like a double two-storey house, each with a room upstairs, called the right and left ‘auricles’. The down stairs rooms are right and left ‘ventricles’.
Every drop of blood circulates the entire body as under. The blood with oxygen from the lungs goes to the left auricle, then to the left ventricle, and then to the “aorta”. This is the great artery and its branches carry the blood to all parts of the body.
Through the medium of capillaries it goes from the smallest arteries into the smallest veins. It flows through the veins which become larger. Finally, it reaches the right auricle and then into right ventricle. From there into arteries which carry it into lungs. Here the carbon dioxide and some water are given up and takes up oxygen. Now it is once again ready to come to the left auricle of the heart and start off on its journey.
The heart squeezes and relaxes about 100,000 times each day and pumps about 1,75,000 litres of blood in 24 hours in an adult made.