HEAT REGULATION IN SOME ARCTIC AND TROPICAL MAMMALS AND BIRDS
HEAT REGULATION IN SOME ARCTIC AND TROPICAL MAMMALS AND BIRDS
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DOI：
10.2307/1538741
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发表时间：
1950-01-01
影响因子：
1.6
通讯作者：
IRVING, L
中科院分区：
文献类型：
--
作者：
SCHOLANDER, PF;HOCK, R;IRVING, L
一系列北极和热带哺乳动物和鸟类在点巴罗，阿拉斯加（lat。71[degree]N）和巴拿马（lat. 9[degree]N）经受各种空气温度。在一个呼吸计。较大的北极型在温度下基础代谢率没有变化。低至-30[degree]C，从对睡眠动物的观察来看，它们的热中性区可能至少延伸到-40[degree]C。较小的北极物种。显示出更高临界温度。和热带种（Tropical spp.）更是代谢产热随温度的降低而迅速增加。在热带哺乳动物或鸟类身上，慢慢地在北极动物身上。在一系列的实验中，包括我们的热带和北极的材料和所有动物提供足够的数据在文献中，它表明，低于临界温度的热损失。基本上与人体对空气的梯度成正比。这意味着整体绝缘显然达到了最大值。在临界温度下，从那时起，热损失基本上遵循牛顿冷却定律。由此可见，北极哺乳动物的临界温度。在-40摄氏度（= 70摄氏度的人体-空气梯度）的环境中，通过加倍新陈代谢，理论上他所能承受的温度梯度也会加倍，只要新陈代谢（或隔热）增加40%左右，就足以使他降到地球上有记录以来的最低温度，即接近-70摄氏度。在较大的北极物种中，从+30[度]到-40[度]，显示了它们平衡梯度增加11倍的能力，因此动物即使躺下也可以将其散热量改变11倍。据信，血管控制不良绝缘腿必须发挥重要作用，在一般的热调节这些动物。在热带哺乳动物和鸟类中。接近他们的体温有时接近10[度]，这使得他们非常敏感，即使是很小的温度。变化10.一个人的温度，一个人的温度。从临界温度坡度加倍，增加9[度]坡度减小10倍。为了保持体温，动物必须能够以与梯度相同的比例调节绝缘和新陈代谢。
A series of arctic and tropical mammals and birds at Point Barrow, Alaska (lat. 71[degree]N) and in Panama (lat. 9[degree]N) was subjected to various air temps. in a respirometer. The larger arctic forms showed no change in basal metabolic rate at temps. as low as -30[degree]C, and from observations on sleeping animals it is probable that their zone of thermoneutrality extends at least to -40[degree]C. The smaller arctic spp. show a higher critical temp. and the tropical spp. even higher. Metabolic heat production increases rapidly with lowering of temp. in a tropical mammal or bird, and slowly in an arctic animal. In a large series of expts., including our tropical and arctic material and all animals affording enough data in the literature, it is shown that heat loss below the critical temp. is essentially proportional to the body-to-air gradient. This means that the overall insulation evidently reaches a max. at the critical temp., and from then on heat loss essentially follows Newton''s law of cooling. It follows from this that an arctic mammal with a critical temp. of -40[degree]C (= 70[degree]C body-to-air gradient),by doubling its metabolism,theoretically would double the gradient he could stand. Only about 40% increase in the metabolism (or insulation) would suffice to take him down to the lowest temperature recorded on earth, namely near -70[degree]C. The very broad zone of thermoneutrality in the larger arctic spp., from +30[degree] to -40[degree], shows their ability to balance an 11-fold increase in the gradient, and hence the animal can change its heat dissipation by a factor of 11 even when lying down. It is believed that vasocontrol of the poorly insulated legs must play an important role in the general heat regulation of these animals. In tropical mammals and birds the critical temp. is near their body temp., sometimes as near as 10[degree], which makes them very sensitive to even small temp. changes. A 10[degree] drop of the air temp. from the critical temp. doubles the gradient, and a 9[degree] increase decreases the gradient 10 times. In order to maintain the body temp., the animal must be able to adjust insulation and metabolism in the same proportion as the gradient.