The human body A beginner's text-book of anatomy, physiology and hygiene .. . y from the back-bone, and the depth of thechest between breast-bone and spinal column is in-creased. That raising the front end of the ribs must push thebreast-bone forwards may be readily understood by ex-amining Fig. 46. In the figure, ab represents the spinalcolumn, and st the position of the ribs in expira-tion is indicated by the rods c andd\ their position in inspiration,by the dotted lines c and d. It isclear that when the ribs are raisedthe sternum must be separatedfarther from the back-bone.
The human body A beginner's text-book of anatomy, physiology and hygiene .. . y from the back-bone, and the depth of thechest between breast-bone and spinal column is in-creased. That raising the front end of the ribs must push thebreast-bone forwards may be readily understood by ex-amining Fig. 46. In the figure, ab represents the spinalcolumn, and st the position of the ribs in expira-tion is indicated by the rods c andd\ their position in inspiration,by the dotted lines c and d. It isclear that when the ribs are raisedthe sternum must be separatedfarther from the back-bone. 21. Action of the Diaphragm dur-ing Inspiration. — The diaphragm(^, Fig. i) is a dome-shaped muscle,with its hollow side turned to-wards the abdomen. When itcontracts, it flattens, and thus in-creases the chest-cavity. At the same time, it pushesdown the liver, stomach, and intestines. These make In inspiration ? What is the result of raising the front ends of theribs? 21. Form of the diaphragm ? How altered when it contracts ? Re-sult as regards the chest? The abdomen ?. Fig. 46.—Diagram of amodel to illustrate how thechest-cavity is increased frombefore back when the frontends of the ribs are raised, abrepresents the spinal column;st^ the breast-bone; <:, d^ theribs in expiration; c\ d\ theribs in inspiration. lE^tPIRA TidN, i/^3 foorh for therriselves by pushing out the soft front wallof the abdomen, which therefore protrudes; 22. The Combined Action of the Diaphragm and of theMuscles which Raise the Ribs is such as to considerablyincrease the chest-cavity. This is illustrated in Fig. B are shown the size and form of the thoraciccavity, and the position of the diaphragm, after an expi-
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Keywords: ., bookcentury1800, bookdecade1, booksubjectphysiology, bookyear1884
