. A text-book in general physiology and anatomy. Physiology, Comparative; Anatomy. 320 BBSPIKATION and the air is forced out of them by the passages above noted. \Miat causes the lungs to expand and fill with air, and, since the lungs themselves contain no muscles, what parts of the body are concerned in this process? The answer to this question is to be foimd in the structure and movements of the walls of the chest cavity. Structure of the chest cavity.— The chest cavity is conical in shape, with the point of the cone at the top, and is completely inclosed on aU sides. The upper part and side
. A text-book in general physiology and anatomy. Physiology, Comparative; Anatomy. 320 BBSPIKATION and the air is forced out of them by the passages above noted. \Miat causes the lungs to expand and fill with air, and, since the lungs themselves contain no muscles, what parts of the body are concerned in this process? The answer to this question is to be foimd in the structure and movements of the walls of the chest cavity. Structure of the chest cavity.— The chest cavity is conical in shape, with the point of the cone at the top, and is completely inclosed on aU sides. The upper part and sides of the cone are formed of the ribs, intercostal muscles, sternum, and backbone, all covered over with muscles and skin, while the floor of the cavity is com- posed of the membrane called the diaphragm. These walls are not rigid, but permit of movement in two defi- nite directions. As we inhale, the sides of the cavity can be felt to move outward, while the diaphragm is pulled downward, forcing the contents of the abdominal cavity in the same direction, and causing the belly to swell under the pressure. As we exhale, the ribs move inward and the diaphragm moves upward, causing the belly to be dra^\'n in. The causes of these movements arp to be found by studying the shape of the ribs and the muscular connec- tions. In the dissection of the chest cavity, the muscles between. Fig. 149 — Diagram of rib movement in breathing; AB, vertebral oolnmn; CD and MF, ribs attached to movable breastbone, DF; a, 6, external and internal in- tercostal muscles ; c, neck 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 Eddy, Walter Hollis, b. 1877. New York, Cincinnati [etc. ] American book Co
Size: 2542px × 983px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectanatomy
