An elementary physiology and hygiene for use in upper grammar grades . emains in the mouthwe can control it, but the moment it enters the oesopha-gus it has passed beyond our control. If we shouldthen discover that it was poison, we should be obliged tokeep on swallowing just the same. The food is pushedthrough the oesophagus into the stomach by the musclesof the throat and oesophagus. It does not simply fall,but it is actually forced down. A person can swallowwater even when he is standing on his head, and a horse,when he drinks, of course swallows the water upward. FOOD IN THE STOMACHThe Sto
An elementary physiology and hygiene for use in upper grammar grades . emains in the mouthwe can control it, but the moment it enters the oesopha-gus it has passed beyond our control. If we shouldthen discover that it was poison, we should be obliged tokeep on swallowing just the same. The food is pushedthrough the oesophagus into the stomach by the musclesof the throat and oesophagus. It does not simply fall,but it is actually forced down. A person can swallowwater even when he is standing on his head, and a horse,when he drinks, of course swallows the water upward. FOOD IN THE STOMACHThe Stomach. — A few seconds after the food hasentered the oesophagus it passes into a large cavity calledthe stomach (see Figs. 13 and 15). This is a chambersimilar to a gourd in shape, lying just below the ribsand a little to the left side of the body. It is closed at DIGESTION 47 both ends by small folds or valves. The valve betweenthe oesophagus and the stomach ordinarily prevents thefood from going back into the oesophagus. Sometimes,however, when ill- •Oesophagta. -Pancreasdp/een ness causes us tovomit or throwup, the valve be-tween the stomachand the oesophagusopens and allowsthe food to returnto the mouth. Thevalve at the lowerend, which con-nects with the tubecalled the intestine,prevents the foodfrom leaving thestomach too 13 showsthe stomach withits valves. Thestomach itself iselastic, and willstretch so as tohold a large amountof food, but it shrinks again as soon as the food passes out. Thestomach of an ordinary grown-up person can hold threepints of food very comfortably. Fig. 13.—The Digestive Organs opthe Abdomen. 48 PHYSIOLOGY AND HYGIENE The outer walls of the stomach consist principally ofmuscular fibers which run around it in various directions,some crosswise, some lengthwise, and some these fibers contract and relax, they cause thestomach to undergo a variety of motions, which mixtogether the different foods inside and keep themmovin
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectphysiology, bookyear1
