The effects of inanition and The effects of inanition and malnutrition upon growth and structure effectsofinaniti00jack Year: 1925 76 INANITION AND MALNUTRITION maintenance requirement, but still subnormal in amount, will cause a retardation in growth proportional to the degree of deficiency. Thus Evans and Bishop ('22) found that on optimum standard diet the albino rat at one year reached a body weight of about 330 g.; slightly underfed, 220 g.; on two-thirds normal ration, 140 g.; and on half ration, 60-85 g. (see Fig. 34). As will be shown later, however, the dystrophic growth under such c
The effects of inanition and The effects of inanition and malnutrition upon growth and structure effectsofinaniti00jack Year: 1925 76 INANITION AND MALNUTRITION maintenance requirement, but still subnormal in amount, will cause a retardation in growth proportional to the degree of deficiency. Thus Evans and Bishop ('22) found that on optimum standard diet the albino rat at one year reached a body weight of about 330 g.; slightly underfed, 220 g.; on two-thirds normal ration, 140 g.; and on half ration, 60-85 g. (see Fig. 34). As will be shown later, however, the dystrophic growth under such circumstances is not only decreased in rate but also often abnormal in character. 360 400 Fig. 34.—Chart showing curves of average growth in female albino rats on various planes of nutrition. The upper curve (light line) represents the average normal growth of littermate controls on an abundance of 'Standard Diet I.' The 3 lower curves in heavier line represent averages for the groups in which this ration was reduced slightly (in the upper curve), about one-third (in the middle curve), and about one-half (in the lower curve), respectively. Circles mark the average times of occurrence of the first estrus, which did not occur at all in the most underfed group. (Evans and Bishop '22.) Prenatal and Larval Inanition.—Since the resistance to inanition in general varies directly with age, it may be inferred that during prenatal or embryonic stages, the organism is particularly susceptible to nutritional deficiencies. This is probably true, but it is somewhat difficult to prove. Especially in mammals the embryo and fetus are carefully protected against inanition by the food supply through the placenta from the mother, even when the latter is severely underfed. In oviparous forms the eggs are usually provided with an abundance of nutrient yolk material, which in part may be carried over into the embryonic body as a reserve supply and may for some time aid in the resistance to inani
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