|
如今托福阅读的背景知识要求越来越多，托福阅读题材也越来越广泛，如果大家不能在新托福阅读的复习时对各种资料有一个了解的话考试的时候会很困难，下面的材料是关于海洋生物的体温调节的知识，希望对大家有帮助。 新托福阅读准备之托福阅读题材：海洋生物的体温调节 托福阅读原文： Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature as its own body temperature, thus avoiding the need for internal thermoregulation. The internal thermoregulation process is one aspect ofhomeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from equilibrium with its environment (the study of such processes in zoology has been called ecophysiology or physiological ecology). If the body is unable to maintain a normal temperature and it increases significantly above normal, a condition known as hyperthermia occurs. For humans, this occurs when the body is exposed to constant temperatures of approximately 55 °C (131 °F), and any prolonged exposure (longer than a few hours) at this temperature and up to around 75 °C (167 °F) death is almost inevitable.[citation needed]Humans may also experience lethal hyperthermia when the wet bulb temperature is sustained above 35 °C (95 °F) for six hours.[1]The opposite condition, when body temperature decreases below normal levels, is known as hypothermia. Whereas an organism that thermoregulates is one that keeps its core body temperature within certain limits, a thermoconformer is subject to changes in body temperature according to changes in the temperature outside of its body at a certain temperature. It was not until the introduction of thermometers that any exact data on the temperature of animals could be obtained. It was then found that local differences were present, since heat production and heat loss vary considerably in different parts of the body, although the circulation of the blood tends to bring about a mean temperature of the internal parts. Hence it is important to identify the parts of the body that most closely reflect the temperature of the internal organs. Also, for such results to be comparable, the measurements must be conducted under comparable conditions. The rectum has traditionally been considered to reflect most accurately the temperature of internal parts, or in some cases of sex or species, the vagina, uterus or bladder. Occasionally the temperature of the urine as it leaves the urethra may be of use in measuring body temperature. More often the temperature is taken in the mouth, axilla,ear or groin. Some animals undergo one of various forms of dormancy where the thermoregulation process temporarily allows the body temperature to drop, thereby conserving energy. Examples include hibernating bears and torpor in bats. 通过上面关于海洋生物的体温调节的知识的托福阅读题材介绍已经又为大家做了不少准备，希望能帮助大家在新托福阅读中取得一个先机，这样托福阅读就能取得进步了。
| 
/1 
窥视卡
雷达卡
发表于 2014-8-28 11:12:07
收藏
提升卡
变色卡
千斤顶
显身卡
