企鹅同其他生活在寒冷地区的鸟一样,都已经适应了寒冷的气候,能够尽可能少地散失热量,保持自己身体主要部分温度在40℃左右。但是它们的脚却很难保暖,因为脚上既不长毛,也没有脂肪的防护,而且还有相对较大的面积。于是,企鹅通过两种机制来防止脚被冻坏。一种机制,是通过改变向双脚提供血液的动脉血管的直径来调节脚内的血液流量。当寒冷时,减少脚部的血液流量;当比较温暖时,增加血液流量。其实我们人类也有类似的机制,所以我们的手 Like other birds living in cold regions, penguins have adapted to the cold climate, losing as little heat as possible, keeping their body temperature around 40 ° C. But their feet are hard to keep warm because they have neither hair nor fat protection on their feet, but also have relatively large areas. As a result, penguins prevent freezing of their feet by two mechanisms. One mechanism is to regulate blood flow in the foot by changing the diameter of the arterial blood supplying blood to both feet. When cold, reduce blood flow to the feet; when warmer, increase blood flow. In fact, we humans have similar mechanisms, so our hands