Animal physiology / by John G. M'Kendrick.

  • John Gray McKendrick
Date:
1877
Catalogue details

Licence: Public Domain Mark

Credit: Animal physiology / by John G. M'Kendrick. Source: Wellcome Collection.

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    urine, saliva, &c. shews that the absorption of fluids must take place very shortly after they are swallowed ; and there is little doubt that the blood-vessels (capillaries) of the stomach constitute the principal channel through which they pass out of the intestinal tract into the blood. 93. Time requiredfor Digestion.—There can be no doubt that the stomach is admirably adapted for the digestion of the food introduced into it, because it has been shewn by numerous experiments that digestion will go on in gastric juice out of the stomach, but that it requires three or four times longer a period than when performed by the stomach itself. In the stomach, in most individuals, rice and tripe are digested in one hour; eggs, salmon, and venison in one and a half hours ; tapioca, liver, fish in two hours; lamb, pork, and turkey in two and a half hours ; beef, mutton, and fowl in three and a half hours ; and veal in four hours. There are, however, considerable differences in various indi- viduals, or even in the same individual at different times. 94. Conditio7is favourable for Good Digestion.—These are : (l) a temperature in the stomach itself of about 100° F. ; (2) constant movement of the walls of the stomach, so as to bring the food thor- oughly into contact with the mucous membrane and gastric juice; (3) the removal from time to time of such portions as have been fully digested ; (4) a state of softness and minute division of the food ; (5) the quantity of food taken—the stomach should be moderately filled, but not distended ; (6) the time which has elapsed since the last meal, which should always be long enough for the food of one meal to have completely left the stomach before another is intro- duced ; (7) the amount of exercise previous and subsequent to a meal, gentle exercise being favourable, while over-exertion is injurious ; (8) the state of the mind, tranquillity of temper favouring good digestion; (9) the general state of the bodily health, the stomach of an invalid not being usually so fit for digestion as that of a person in robust health ; and (10) the period of life, digestion being more active in the young than in the old. 95. For7}i of the Stomach in various Animals.—The form and dimensions of the stomach correspond to the kind of food on which the animal lives. Carnivorotis animals, such as the hyena (fig. 59, B), have a simple stomach, as their food is easily digested ; while those which live on vegetable food, or herbivora^ such as a
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