. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. CIRCULATION 355 lar tubes, side by side, each having two chambers (auricle and ventricle). As the large arteries pass away from the heart, the diameter of each individual artery becomes smaller. At the very end of their course, these arteries are so small as to be almost microscopic in size. They are very numerous. There are so many that if they were placed together, side by side, their united diameter would be much greater than the diameter of the large artery (aorta) which passes blood fr
. Elements of biology; a practical text-book correlating botany, zoology, and human physiology. Biology. CIRCULATION 355 lar tubes, side by side, each having two chambers (auricle and ventricle). As the large arteries pass away from the heart, the diameter of each individual artery becomes smaller. At the very end of their course, these arteries are so small as to be almost microscopic in size. They are very numerous. There are so many that if they were placed together, side by side, their united diameter would be much greater than the diameter of the large artery (aorta) which passes blood from the left side of the heart. This fact is of very great importance, for the force of the blood as it gushes through the arteries becomes very much less when it reaches the smaller vessels. This gushing movement is quite lost when the capillaries are reached. First, because there is so much more space for the blood to fill; secondly, there is considerable friction caused by the very tiny diameter of the capillaries. Capillary NetworH. Capillary network, showing change from arterial to venous blood. Capillaries.—The capillaries form a network of minute tubes everywhere in the body, but especially near the surface and in the lungs. It is through their walls that the food and oxygen pass to the tissues, and carbon dioxide is given up to the plasma. They form the connection that completes the system of circulation of blood in the body. Function and Structure of the Veins. — If the arteries are pipes which supply fluid food to the tissues, then the veins may be likened to drain pipes which carry away waste material from the tissues. Extremely numerous in the extremities and in the muscles and among other tissues of the body, they, like the branches of a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hunter
Size: 2220px × 1126px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookpublishernewyorkamericanbookcompany, booksubjectbiology
