疣体是什么病| 痴男怨女是什么意思| 汤圆和元宵有什么区别| bye什么意思| 饺子什么馅儿最好吃| 翘首企盼是什么意思| 低血压高是什么原因造成的| 牙根出血是什么原因| 男人补锌有什么好处| 头顶冒汗是什么原因| 额头反复长痘是什么原因| 寄生树有什么功效作用| 酸奶可以做什么美食| 浇花的水壶叫什么| 狐臭去医院挂什么科| 左边头疼是什么原因怎么办| 白色和什么颜色搭配最好看| feat什么意思| 彩蛋是什么意思| 休止期脱发什么意思| diy是什么| 孕妇快生的时候有什么征兆| 9月9号什么星座| 怀孕初期需要注意些什么| 头皮毛囊炎用什么洗发水| 宫颈炎吃什么药最好| 治疗神经痛用什么药最有效| 漏斗胸是什么原因造成的| 30年婚姻叫什么婚| 下面老是痒是什么原因| 凤梨和菠萝的区别是什么| 叶酸什么时间吃最好| 1975年五行属什么| 什么是幼小衔接| 引什么大叫| 丙二醇是什么| 月子餐第一周吃什么| 梦到大牙掉了一颗是什么意思| 为什么腹部隐隐作痛| 塔罗牌是什么意思| daogrs是什么牌子| 上传下达什么意思| r的平方是什么意思| 蔓越莓有什么功效和作用| 肝脏钙化灶什么意思| 芳心是什么意思| 胸痒痒是什么原因| 白色裤子搭什么颜色上衣| 七月半是什么节日| 来大姨妈不能吃什么水果| zero是什么牌子| 抗hp治疗是什么意思| 丁什么丁什么成语| 导师是什么意思| 四时是什么意思| 植物园有什么植物| 好雅兴是什么意思| 竹外桃花三两枝的下一句是什么| 晚上11点到12点是什么时辰| 为什么会尿频| 什么是微循环| 属鼠和什么属相最配| 脚后跟疼挂什么科| 皮肤病挂什么科| 坐骨神经痛用什么药| 大连六院是什么医院| mw是什么意思| 企鹅吃什么食物| 什么葡萄品种最好吃| 附耳是什么| 羊水穿刺检查什么| MC是什么牌子的车| 关羽的马叫什么名字| 护身符是什么意思| 甲壳素是什么东西| 窒息是什么意思| 涤塔夫是什么面料| 迂回战术什么意思| 左侧卵巢内囊性回声是什么意思| 纪念礼物送什么好| 三合是什么意思| 女生不来大姨妈是什么原因| 螺旋杆菌感染吃什么药| 奇行种什么意思| 獭读什么| 六月二十六是什么星座| 致意是什么意思| 做完雾化为什么要漱口| 金与什么相生相克| 1923年属什么生肖| 湿度大对人体有什么影响| 小孩嗓子哑了吃什么药| 口苦口臭挂什么科| 月经推迟是什么原因| 喝水多尿少是什么原因| 天丝是什么成分| 滴滴什么意思网络用语| 一直咳嗽不见好是什么原因| 婴儿感冒吃什么药| 流涎是什么意思| 硌脚是什么意思| 血压低头疼是什么原因| 木耳炒什么| 钙片吃多了有什么副作用| 红线是什么意思| 什么叫寓言故事| 脑溢血是什么原因| 夏天吃什么| 眩晕症是什么原因引起的| 宫颈欠光滑是什么意思| 鼻炎是什么引起的| 媱字五行属什么| 上眼皮肿是什么原因| 孕妇吃什么鱼对胎儿好| 人老是犯困想睡觉是什么原因| 汗管瘤什么原因造成| 经常吃海带有什么好处和坏处| 欲言又止是什么意思| 高铁动力来源是什么| 查血压高挂什么科室| 塌陷是什么意思| 什么是初心| 孩子肚子疼是什么原因| evian是什么品牌| 什么东西不能托运| 七九年属什么| 送老爸什么礼物| 本科专科有什么区别| 筠字五行属什么| 2039年是什么年| 水浒传有什么故事| 支气管炎吃什么药效果最好| 不走寻常路是什么品牌| 9月25是什么星座| 苦瓜泡酒有什么功效和作用| 抽动症是什么引起的| 外围什么意思| 公分的单位是什么| 青霉素过敏吃什么消炎药| 心慌挂什么科| 什么症状需要做肠镜| 周星驰为什么不结婚| jackjones是什么品牌| 奕五行属什么| 6d是什么意思| 贾琏为什么叫二爷| 什么时候同房容易怀孕| 孕妇做梦梦到蛇是什么意思| 包袱是什么意思| 胃炎不能吃什么| 月例是什么意思| 春天像什么的比喻句| 牙龈炎吃什么消炎药| cachecache是什么牌子| 胰腺是什么| 外阴白斑擦什么药| 为什么会得荨麻疹| 拔牙挂什么科| 尿发绿是什么原因| 用激素药有什么副作用| 男命正印代表什么| 细菌性阴道炎用什么药好得快| 阴挺是什么意思| 万事如意是什么生肖| 拔凉拔凉是什么意思| 慢性肠炎用什么药| 五音是什么意思| 刚柔并济是什么意思| 尿酸高的人不能吃什么| pic什么意思| 乔迁送什么花| 牛后腿肉适合做什么| 中医是什么| hia是什么意思| 竞走是什么意思| 菲律宾货币叫什么| 心跳和心率有什么区别| 什么是结核病| 骶1隐裂是什么意思| 肠炎有什么症状表现| 师姐是什么意思| 横空出世是什么意思| 太妹是什么意思| 口苦口干是什么原因引起的| 膝关节积液是什么原因造成的| 贲临是什么意思| 体毛多是什么原因| 离婚需要什么资料| 股癣用什么药膏好得快| 电磁炉滴滴响不加热是什么原因| 现在什么星座| 吃什么补血贫血| top1什么意思| 一毛不拔是什么生肖| 科技布是什么材质| 婴儿头发长得慢是什么原因| 当归有什么作用和功效| 发光免疫是检查什么的| 甲状腺适合吃什么食物| 女命比肩代表什么| 武夷肉桂茶属于什么茶| 巴马汤泡脚有什么功效| 深度睡眠是什么意思| 赵国是现在的什么地方| 脾主什么| 嬉皮笑脸是什么生肖| 追什么| 痰多吃什么化痰| 旦辞爷娘去的旦是什么意思| 细小是什么| 遗精是什么意思啊| 梦见死尸什么预兆| 指的是什么| 身体发凉是什么原因| fps是什么意思| 判处死刑缓期二年执行是什么意思| 纯字五行属什么| 三点水一个希读什么| 小孩小便红色是什么原因| 起风疹的原因是什么引起的| 金玉良缘是什么生肖| 什么叫介入治疗| cmn是什么意思| 作业是什么意思| 拉伤筋用什么药好| 脸上长斑是什么原因| 偏头痛挂什么科| 丑拒是什么意思| 背痛是什么原因引起的| 为什么养鱼养单不养双| 做肝功能检查挂什么科| 虎头蛇尾是什么意思| 闯空门什么意思| 风心病是什么病| 桥本是什么| 响是什么意思| 梦到头发长长了是什么意思| 如饥似渴是什么意思| 负面情绪是什么意思| 反胃吃什么药| 女大七岁有什么说法| 什么是辣木籽| 蹭蹭是什么意思| 稼穑是什么意思| 头晕耳鸣是什么原因引起的| 夏天感冒咳嗽吃什么药| 脚发麻是什么原因| 植发用什么头发| 什么眼型最好看| 伤口撒什么药粉好得快| 火命适合什么颜色| 石斛有什么用| 什么是高脂血症| 风热证是什么意思| 什么菜煮不熟| 女性尿路感染是什么原因造成的| 蝗虫用什么呼吸| 无脑是什么意思| 眼有眼屎是什么原因| 婴儿采足底血是查什么| 甘油三酯高吃什么药能降下来| 易经是什么| 王毅什么级别| 从头再来什么意思| 百度Jump to content

《青春戏苑》 20180320 魅力黄梅

From Wikipedia, the free encyclopedia
百度 全国31省区市将陆续进入“两会时间”。

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 of homeostasis: a state of dynamic stability in an organism's internal conditions, maintained far from thermal equilibrium with its environment (the study of such processes in zoology has been called physiological ecology).

If the body is unable to maintain a normal temperature and it increases significantly above normal, a condition known as hyperthermia occurs. Humans may also experience lethal hyperthermia when the wet bulb temperature is sustained above 35 °C (95 °F) for six hours.[1] Work in 2022 established by experiment that a wet-bulb temperature exceeding 30.55 °C caused uncompensable heat stress in young, healthy adult humans. The opposite condition, when body temperature decreases below normal levels, is known as hypothermia. It results when the homeostatic control mechanisms of heat within the body malfunction, causing the body to lose heat faster than producing it. Normal body temperature is around 37 °C (98.6 °F), and hypothermia sets in when the core body temperature gets lower than 35 °C (95 °F).[2] Usually caused by prolonged exposure to cold temperatures, hypothermia is usually treated by methods that attempt to raise the body temperature back to a normal range.[3]

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.[4] 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.

Classification of animals by thermal characteristics

[edit]

Endothermy vs. ectothermy

[edit]

Thermoregulation in organisms runs along a spectrum from endothermy to ectothermy. Endotherms create most of their heat via metabolic processes and are colloquially referred to as warm-blooded. When the surrounding temperatures are cold, endotherms increase metabolic heat production to keep their body temperature constant, thus making the internal body temperature of an endotherm more or less independent of the temperature of the environment.[5] Endotherms possess a larger number of mitochondria per cell than ectotherms, enabling them to generate more heat by increasing the rate at which they metabolize fats and sugars.[6] Ectotherms use external sources of temperature to regulate their body temperatures. They are colloquially referred to as cold-blooded despite the fact that body temperatures often stay within the same temperature ranges as warm-blooded animals. Ectotherms are the opposite of endotherms when it comes to regulating internal temperatures. In ectotherms, the internal physiological sources of heat are of negligible importance; the biggest factor that enables them to maintain adequate body temperatures is due to environmental influences. Living in areas that maintain a constant temperature throughout the year, like the tropics or the ocean, has enabled ectotherms to develop behavioral mechanisms that respond to external temperatures, such as sun-bathing to increase body temperature, or seeking the cover of shade to lower body temperature.[6][5]

Ectotherms

[edit]
Seeking shade is one method of cooling. Here sooty tern chicks are using a black-footed albatross chick for shade.

Ectothermic cooling

[edit]
  • Vaporization:
  • Convection:
    • Increasing blood flow to body surfaces to maximize heat transfer across the advective gradient.
  • Conduction:
    • Losing heat by being in contact with a colder surface. For instance:
      • Lying on cool ground.
      • Staying wet in a river, lake or sea.
      • Covering in cool mud.
  • Radiation:
    • Releasing heat by radiating it away from the body.

Ectothermic heating (or minimizing heat loss)

[edit]
The red line represents the air temperature.
The purple line represents the body temperature of the lizard.
The green line represents the base temperature of the burrow.
Lizards are ectotherms and use behavioral adaptations to control their temperature. They regulate their behavior based on the temperature outside, if it is warm they will go outside up to a point and return to their burrow as necessary.
  • Convection:
    • Climbing to higher ground up trees, ridges, rocks.
    • Entering a warm water or air current.
    • Building an insulated nest or burrow.
  • Conduction:
    • Lying on a hot surface.
  • Radiation:
    • Lying in the sun (heating this way is affected by the body's angle in relation to the sun).
    • Folding skin to reduce exposure.
    • Concealing wing surfaces.
    • Exposing wing surfaces.
  • Insulation:
    • Changing shape to alter surface/volume ratio.
    • Inflating the body.
Thermographic image of a snake around an arm

To cope with low temperatures, some fish have developed the ability to remain functional even when the water temperature is below freezing; some use natural antifreeze or antifreeze proteins to resist ice crystal formation in their tissues.[7] Amphibians and reptiles cope with heat gain by evaporative cooling and behavioral adaptations. An example of behavioral adaptation is that of a lizard lying in the sun on a hot rock in order to heat through radiation and conduction.[citation needed]

Endothermy

[edit]

An endotherm is an animal that regulates its own body temperature, typically by keeping it at a constant level. To regulate body temperature, an organism may need to prevent heat gains in arid environments. Evaporation of water, either across respiratory surfaces or across the skin in those animals possessing sweat glands, helps in cooling body temperature to within the organism's tolerance range. Animals with a body covered by fur have limited ability to sweat, relying heavily on panting to increase evaporation of water across the moist surfaces of the lungs and the tongue and mouth. Mammals like cats, dogs and pigs, rely on panting or other means for thermal regulation and have sweat glands only in foot pads and snout. The sweat produced on pads of paws and on palms and soles mostly serves to increase friction and enhance grip. Birds also counteract overheating by gular fluttering, or rapid vibrations of the gular (throat) skin.[8] Down feathers trap warm air acting as excellent insulators just as hair in mammals acts as a good insulator. Mammalian skin is much thicker than that of birds and often has a continuous layer of insulating fat beneath the dermis. In marine mammals, such as whales, or animals that live in very cold regions, such as the polar bears, this is called blubber. Dense coats found in desert endotherms also aid in preventing heat gain such as in the case of the camels.[citation needed]

A cold weather strategy is to temporarily decrease metabolic rate, decreasing the temperature difference between the animal and the air and thereby minimizing heat loss. Furthermore, having a lower metabolic rate is less energetically expensive. Many animals survive cold frosty nights through torpor, a short-term temporary drop in body temperature. Organisms, when presented with the problem of regulating body temperature, have not only behavioural, physiological, and structural adaptations but also a feedback system to trigger these adaptations to regulate temperature accordingly. The main features of this system are stimulus, receptor, modulator, effector and then the feedback of the newly adjusted temperature to the stimulus. This cyclical process aids in homeostasis.[citation needed]

Homeothermy compared with poikilothermy

[edit]

Homeothermy and poikilothermy refer to how stable an organism's deep-body temperature is. Most endothermic organisms are homeothermic, like mammals. However, animals with facultative endothermy are often poikilothermic, meaning their temperature can vary considerably. Most fish are ectotherms, as most of their heat comes from the surrounding water. However, almost all fish are poikilothermic.[citation needed]

Vertebrates

[edit]

By numerous observations upon humans and other animals, John Hunter showed that the essential difference between the so-called warm-blooded and cold-blooded animals lies in observed constancy of the temperature of the former, and the observed variability of the temperature of the latter. Almost all birds and mammals have a high temperature almost constant and independent of that of the surrounding air (homeothermy). Almost all other animals display a variation of body temperature, dependent on their surroundings (poikilothermy).[9]

Brain control

[edit]

Thermoregulation in both ectotherms and endotherms is primarily controlled by the preoptic area (POA) of the anterior hypothalamus.[10][11][12] In rats, neurons in the POA that express the prostaglandin E receptor 3 (EP3) play a crucial role in thermoregulation by regulating body temperature in both directions.[13] EP3-expressing neurons in the POA provide continuous (tonic) inhibitory signals with the transmitter gamma-aminobutyric acid (GABA) to control sympathetic output neurons in the dorsomedial hypothalamus (DMH) and the rostral raphe pallidus nucleus of the medulla oblongata (rRPa).[13][14] In a hot environment, the tonic inhibitory signals from EP3-expressing POA neurons are augmented to suppress sympathetic output. This results in suppressed heat production and dilated skin blood vessels, the latter of which promote heat loss from the body surface. In a cold environment, the tonic inhibition from EP3-expressing POA neurons is attenuated to increase (disinhibit) sympathetic output. This results in increased heat production and constricted skin blood vessels to reduce heat loss.[13][15] The tonic inhibition from EP3-expressing POA neurons is also attenuated by an action of prostaglandin E2 (PGE2) to induce fever.[13] This tonic inhibitory control of body temperature was first proposed as a fever mechanism in 2002[14] and was demonstrated to be the fundamental principle of body temperature homeostasis in mammals in 2022.[13] Such homeostatic control is separate from the sensation of temperature.[16][17]

In birds and mammals

[edit]
Kangaroo licking its arms to cool down

In cold environments, birds and mammals employ the following adaptations and strategies to minimize heat loss:[citation needed]

  1. Using small smooth muscles (arrector pili in mammals), which are attached to feather or hair shafts; this distorts the surface of the skin making feather/hair shaft stand erect (called goose bumps or goose pimples) which slows the movement of air across the skin and minimizes heat loss.
  2. Increasing body size to more easily maintain core body temperature (warm-blooded animals in cold climates tend to be larger than similar species in warmer climates (see Bergmann's rule))
  3. Having the ability to store energy as fat for metabolism
  4. Have shortened extremities
  5. Have countercurrent blood flow in extremities – this is where the warm arterial blood travelling to the limb passes the cooler venous blood from the limb and heat is exchanged warming the venous blood and cooling the arterial (e.g., Arctic wolf[18] or penguins[19])

In warm environments, birds and mammals employ the following adaptations and strategies to maximize heat loss:

  1. Behavioural adaptations like living in burrows during the day and being nocturnal
  2. Evaporative cooling by perspiration and panting
  3. Storing fat reserves in one place (e.g., camel's hump) to avoid its insulating effect
  4. Elongated, often vascularized extremities to conduct body heat to the air

In humans

Simplified control circuit of human thermoregulation.[20]

As in other mammals, thermoregulation is an important aspect of human homeostasis. Most body heat is generated in the deep organs, especially the liver, brain, and heart, and in contraction of skeletal muscles.[21] Humans have been able to adapt to a great diversity of climates, including hot humid and hot arid. High temperatures pose serious stresses for the human body, placing it in great danger of injury or even death. For example, one of the most common reactions to hot temperatures is heat exhaustion, which is an illness that could happen if one is exposed to high temperatures, resulting in some symptoms such as dizziness, fainting, or a rapid heartbeat.[22][23] For humans, adaptation to varying climatic conditions includes both physiological mechanisms resulting from evolution and behavioural mechanisms resulting from conscious cultural adaptations.[24][25] The physiological control of the body's core temperature takes place primarily through the hypothalamus, which assumes the role as the body's "thermostat".[26] This organ possesses control mechanisms as well as key temperature sensors, which are connected to nerve cells called thermoreceptors.[27] Thermoreceptors come in two subcategories; ones that respond to cold temperatures and ones that respond to warm temperatures. Scattered throughout the body in both peripheral and central nervous systems, these nerve cells are sensitive to changes in temperature and are able to provide useful information to the hypothalamus through the process of negative feedback, thus maintaining a constant core temperature.[28][29]

A dog panting after exercise

There are four avenues of heat loss: evaporation, convection, conduction, and radiation. If skin temperature is greater than that of the surrounding air temperature, the body can lose heat by convection and conduction. However, if air temperature of the surroundings is greater than that of the skin, the body gains heat by convection and conduction. In such conditions, the only means by which the body can rid itself of heat is by evaporation. So, when the surrounding temperature is higher than the skin temperature, anything that prevents adequate evaporation will cause the internal body temperature to rise.[30] During intense physical activity (e.g. sports), evaporation becomes the main avenue of heat loss.[31] Humidity affects thermoregulation by limiting sweat evaporation and thus heat loss.[32]

In reptiles

[edit]

Thermoregulation is also an integral part of a reptile's life, specifically lizards such as Microlophus occipitalis and Ctenophorus decresii who must change microhabitats to keep a constant body temperature.[33][34] By moving to cooler areas when it is too hot and to warmer areas when it is cold, they can thermoregulate their temperature to stay within their necessary bounds.[citation needed]

In plants

[edit]

Thermogenesis occurs in the flowers of many plants in the family Araceae as well as in cycad cones.[35] In addition, the sacred lotus (Nelumbo nucifera) is able to thermoregulate itself,[36] remaining on average 20 °C (36 °F) above air temperature while flowering. Heat is produced by breaking down the starch that was stored in their roots,[37] which requires the consumption of oxygen at a rate approaching that of a flying hummingbird.[38]

One possible explanation for plant thermoregulation is to provide protection against cold temperature. For example, the skunk cabbage is not frost-resistant, yet it begins to grow and flower when there is still snow on the ground.[35] Another theory is that thermogenicity helps attract pollinators, which is borne out by observations that heat production is accompanied by the arrival of beetles or flies.[39]

Some plants are known to protect themselves against colder temperatures using antifreeze proteins. This occurs in wheat (Triticum aestivum), potatoes (Solanum tuberosum) and several other angiosperm species.[7]

Behavioral temperature regulation

[edit]

Animals other than humans regulate and maintain their body temperature with physiological adjustments and behavior. Desert lizards are ectotherms, and therefore are unable to regulate their internal temperature themselves. To regulate their internal temperature, many lizards relocate themselves to a more environmentally favorable location. They may do this in the morning only by raising their head from its burrow and then exposing their entire body. By basking in the sun, the lizard absorbs solar heat. It may also absorb heat by conduction from heated rocks that have stored radiant solar energy. To lower their temperature, lizards exhibit varied behaviors. Sand seas, or ergs, produce up to 57.7 °C (135.9 °F), and the sand lizard will hold its feet up in the air to cool down, seek cooler objects with which to contact, find shade, or return to its burrow. They also go to their burrows to avoid cooling when the temperature falls. Aquatic animals can also regulate their temperature behaviorally by changing their position in the thermal gradient.[40] Sprawling prone in a cool shady spot, "splooting," has been observed in squirrels on hot days.[41]

During cold weather, many animals increase their thermal inertia by huddling.

Animals also engage in kleptothermy in which they share or steal each other's body warmth. Kleptothermy is observed, particularly amongst juveniles, in endotherms such as bats[42] and birds (such as the mousebird[43] and emperor penguin[44]). This allows the individuals to increase their thermal inertia (as with gigantothermy) and so reduce heat loss.[45] Some ectotherms share burrows of ectotherms. Other animals exploit termite mounds.[46][47]

Some animals living in cold environments maintain their body temperature by preventing heat loss. Their fur grows more densely to increase the amount of insulation. Some animals are regionally heterothermic and are able to allow their less insulated extremities to cool to temperatures much lower than their core temperature—nearly to 0 °C (32 °F). This minimizes heat loss through less insulated body parts, like the legs, feet (or hooves), and nose.[citation needed]

Different species of Drosophila found in the Sonoran Desert will exploit different species of cacti based on the thermotolerance differences between species and hosts. For example, Drosophila mettleri is found in cacti like the saguaro and senita; these two cacti remain cool by storing water. Over time, the genes selecting for higher heat tolerance were reduced in the population due to the cooler host climate the fly is able to exploit.[citation needed]

Some flies, such as Lucilia sericata, lay their eggs en masse. The resulting group of larvae, depending on its size, is able to thermoregulate and keep itself at the optimum temperature for development.[citation needed]

An ostrich can keep its body temperature relatively constant, even though the environment can be very hot during the day and cold at night.

Koalas also can behaviorally thermoregulate by seeking out cooler portions of trees on hot days. They preferentially wrap themselves around the coolest portions of trees, typically near the bottom, to increase their passive radiation of internal body heat.[48]

Hibernation, estivation and daily torpor

[edit]

To cope with limited food resources and low temperatures, some mammals hibernate during cold periods. To remain in "stasis" for long periods, these animals build up brown fat reserves and slow all body functions. True hibernators (e.g., groundhogs) keep their body temperatures low throughout hibernation whereas the core temperature of false hibernators (e.g., bears) varies; occasionally the animal may emerge from its den for brief periods. Some bats are true hibernators and rely upon a rapid, non-shivering thermogenesis of their brown fat deposit to bring them out of hibernation.[49]

Estivation is similar to hibernation, however, it usually occurs in hot periods to allow animals to avoid high temperatures and desiccation. Both terrestrial and aquatic invertebrate and vertebrates enter into estivation. Examples include lady beetles (Coccinellidae),[50] North American desert tortoises, crocodiles, salamanders, cane toads,[51] and the water-holding frog.[52]

Daily torpor occurs in small endotherms like bats and hummingbirds, which temporarily reduces their high metabolic rates to conserve energy.[53]

Variation in animals

[edit]
Chart showing diurnal variation in body temperature.

Normal human temperature

[edit]

Previously, average oral temperature for healthy adults had been considered 37.0 °C (98.6 °F), while normal ranges are 36.1 to 37.8 °C (97.0 to 100.0 °F). In Poland and Russia, the temperature had been measured axillarily (under the arm). 36.6 °C (97.9 °F) was considered "ideal" temperature in these countries, while normal ranges are 36.0 to 36.9 °C (96.8 to 98.4 °F).[54]

Recent studies suggest that the average temperature for healthy adults is 36.8 °C (98.2 °F) (same result in three different studies). Variations (one standard deviation) from three other studies are:

  • 36.4–37.1 °C (97.5–98.8 °F)
  • 36.3–37.1 °C (97.3–98.8 °F) for males,
    36.5–37.3 °C (97.7–99.1 °F) for females
  • 36.6–37.3 °C (97.9–99.1 °F)[55]

Measured temperature varies according to thermometer placement, with rectal temperature being 0.3–0.6 °C (0.5–1.1 °F) higher than oral temperature, while axillary temperature is 0.3–0.6 °C (0.5–1.1 °F) lower than oral temperature.[56] The average difference between oral and axillary temperatures of Indian children aged 6–12 was found to be only 0.1 °C (standard deviation 0.2 °C),[57] and the mean difference in Maltese children aged 4–14 between oral and axillary temperature was 0.56 °C, while the mean difference between rectal and axillary temperature for children under 4 years old was 0.38 °C.[58]

Variations due to circadian rhythms

[edit]

In humans, a diurnal variation has been observed dependent on the periods of rest and activity, lowest at 11 p.m. to 3 a.m. and peaking at 10 a.m. to 6 p.m. Monkeys also have a well-marked and regular diurnal variation of body temperature that follows periods of rest and activity, and is not dependent on the incidence of day and night; nocturnal monkeys reach their highest body temperature at night and lowest during the day. Sutherland Simpson and J.J. Galbraith observed that all nocturnal animals and birds – whose periods of rest and activity are naturally reversed through habit and not from outside interference – experience their highest temperature during the natural period of activity (night) and lowest during the period of rest (day).[9] Those diurnal temperatures can be reversed by reversing their daily routine.[59]

In essence, the temperature curve of diurnal birds is similar to that of humans and other homeothermic animals, except that the maximum occurs earlier in the afternoon and the minimum earlier in the morning. Also, the curves obtained from rabbits, guinea pigs, and dogs were quite similar to those from humans.[9] These observations indicate that body temperature is partially regulated by circadian rhythms.[citation needed]

Variations due to human menstrual cycles

[edit]

During the follicular phase (which lasts from the first day of menstruation until the day of ovulation), the average basal body temperature in women ranges from 36.45 to 36.7 °C (97.61 to 98.06 °F). Within 24 hours of ovulation, women experience an elevation of 0.15–0.45 °C (0.27–0.81 °F) due to the increased metabolic rate caused by sharply elevated levels of progesterone. The basal body temperature ranges between 36.7–37.3 °C (98.1–99.1 °F) throughout the luteal phase, and drops down to pre-ovulatory levels within a few days of menstruation.[60] Women can chart this phenomenon to determine whether and when they are ovulating, so as to aid conception or contraception.[citation needed]

Variations due to fever

[edit]

Fever is a regulated elevation of the set point of core temperature in the hypothalamus, caused by circulating pyrogens produced by the immune system.[61] To the subject, a rise in core temperature due to fever may result in feeling cold in an environment where people without fever do not.[citation needed]

Variations due to biofeedback

[edit]

Some monks are known to practice Tummo, biofeedback meditation techniques, that allow them to raise their body temperatures substantially.[62]

Effect on lifespan

[edit]

The effects of such a genetic change in body temperature on longevity is difficult to study in humans.[63]

Limits compatible with life

[edit]

There are limits both of heat and cold that an endothermic animal can bear and other far wider limits that an ectothermic animal may endure and yet live. The effect of too extreme a cold is to decrease metabolism, and hence to lessen the production of heat. Both catabolic and anabolic pathways share in this metabolic depression, and, though less energy is used up, still less energy is generated. The effects of this diminished metabolism become telling on the central nervous system first, especially the brain and those parts concerning consciousness;[64] both heart rate and respiration rate decrease; judgment becomes impaired as drowsiness supervenes, becoming steadily deeper until the individual loses consciousness; without medical intervention, death by hypothermia quickly follows. Occasionally, however, convulsions may set in towards the end, and death is caused by asphyxia.[65][64]

In experiments on cats performed by Sutherland Simpson and Percy T. Herring, the animals were unable to survive when rectal temperature fell below 16 °C (61 °F).[64] At this low temperature, respiration became increasingly feeble; heart-impulse usually continued after respiration had ceased, the beats becoming very irregular, appearing to cease, then beginning again. Death appeared to be mainly due to asphyxia, and the only certain sign that it had taken place was the loss of knee-jerks.[65]

However, too high a temperature speeds up the metabolism of different tissues to such a rate that their metabolic capital is soon exhausted. Blood that is too warm produces dyspnea by exhausting the metabolic capital of the respiratory centre;[66] heart rate is increased; the beats then become arrhythmic and eventually cease. The central nervous system is also profoundly affected by hyperthermia and delirium, and convulsions may set in. Consciousness may also be lost, propelling the person into a comatose condition. These changes can sometimes also be observed in patients experiencing an acute fever.[citation needed] Mammalian muscle becomes rigid with heat rigor at about 50 °C, with the sudden rigidity of the whole body rendering life impossible.[65]

H.M. Vernon performed work on the death temperature and paralysis temperature (temperature of heat rigor) of various animals. He found that species of the same class showed very similar temperature values, those from the Amphibia examined being 38.5 °C, fish 39 °C, reptiles 45 °C, and various molluscs 46 °C.[citation needed] Also, in the case of pelagic animals, he showed a relation between death temperature and the quantity of solid constituents of the body. In higher animals, however, his experiments tend to show that there is greater variation in both the chemical and physical characteristics of the protoplasm and, hence, greater variation in the extreme temperature compatible with life.[65]

A 2022 study on the effect of heat on young people found that the critical wet-bulb temperature at which heat stress can no longer be compensated, Twb,crit, in young, healthy adults performing tasks at modest metabolic rates mimicking basic activities of daily life was much lower than the 35 °C usually assumed, at about 30.55 °C in 36–40 °C humid environments, but progressively decreased in hotter, dry ambient environments.[67][68]

Arthropoda

[edit]

The maximum temperatures tolerated by certain thermophilic arthropods exceeds the lethal temperatures for most vertebrates.[69]

The most heat-resistant insects are three genera of desert ants recorded from three different parts of the world. The ants have developed a lifestyle of scavenging for short durations during the hottest hours of the day, in excess of 50 °C (122 °F), for the carcasses of insects and other forms of life which have died from heat stress.[70]

In April 2014, the South Californian mite Paratarsotomus macropalpis has been recorded as the world's fastest land animal relative to body length, at a speed of 322 body lengths per second. Besides the unusually great speed of the mites, the researchers were surprised to find the mites running at such speeds on concrete at temperatures up to 60 °C (140 °F), which is significant because this temperature is well above the lethal limit for the majority of animal species. In addition, the mites are able to stop and change direction very quickly.[69]

Spiders like Nephila pilipes exhibits active thermal regulation behavior.[71] During high temperature sunny days, it aligns its body with the direction of sunlight to reduce the body area under direct sunlight.[71]

See also

[edit]

References

[edit]
  1. ^ "Global Warming: Future Temperatures Could Exceed Livable Limits, Researchers Find".
  2. ^ "Hypothermia". Mayo Clinic. Retrieved 1 May 2017.
  3. ^ "Hypothermia: Causes, Symptoms, and Treatment". WebMD. Retrieved 1 May 2017.
  4. ^ Chisholm 1911, p. 48.
  5. ^ a b "Khan Academy". Khan Academy. Retrieved 3 April 2017.
  6. ^ a b Boundless (20 September 2016). "Homeostasis: Thermoregulation". Boundless. Archived from the original on 4 April 2017. Retrieved 3 April 2017.
  7. ^ a b Crevel, R.W.R; Fedyk, J.K; Spurgeon, M.J (July 2002). "Antifreeze proteins: characteristics, occurrence and human exposure". Food and Chemical Toxicology. 40 (7): 899–903. doi:10.1016/S0278-6915(02)00042-X. PMID 12065210.
  8. ^ Hill, Richard (2016). Animal Physiology. Sinauer. p. 270. ISBN 9781605354712.
  9. ^ a b c Chisholm 1911, p. 49.
  10. ^ Nakamura, Kazuhiro (November 2011). "Central circuitries for body temperature regulation and fever". American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 301 (5): R1207 – R1228. doi:10.1152/ajpregu.00109.2011. ISSN 0363-6119.
  11. ^ Romanovsky, AA (2007). "Functional architecture of the thermoregulatory system". Am J Physiol Regul Integr Comp Physiol. 292 (1): R37–46. doi:10.1152/ajpregu.00668.2006. PMID 17008453. S2CID 1163257.
  12. ^ Morrison, S.F.; Nakamura, K. (10 February 2019). "Central Mechanisms for Thermoregulation". Annual Review of Physiology. 81 (1): 285–308. doi:10.1146/annurev-physiol-020518-114546. ISSN 0066-4278.
  13. ^ a b c d e Nakamura, Yoshiko; Yahiro, Takaki; Fukushima, Akihiro; Kataoka, Naoya; Hioki, Hiroyuki; Nakamura, Kazuhiro (23 December 2022). "Prostaglandin EP3 receptor–expressing preoptic neurons bidirectionally control body temperature via tonic GABAergic signaling". Science Advances. 8 (51). doi:10.1126/sciadv.add5463. ISSN 2375-2548. PMC 9788766. PMID 36563142.
  14. ^ a b Nakamura, Kazuhiro; Matsumura, Kiyoshi; Kaneko, Takeshi; Kobayashi, Shigeo; Katoh, Hironori; Negishi, Manabu (1 June 2002). "The Rostral Raphe Pallidus Nucleus Mediates Pyrogenic Transmission from the Preoptic Area". The Journal of Neuroscience. 22 (11): 4600–4610. doi:10.1523/JNEUROSCI.22-11-04600.2002. ISSN 0270-6474. PMC 6758794. PMID 12040067.
  15. ^ Nakamura, Kazuhiro; Nakamura, Yoshiko; Kataoka, Naoya (January 2022). "A hypothalamomedullary network for physiological responses to environmental stresses". Nature Reviews Neuroscience. 23 (1): 35–52. doi:10.1038/s41583-021-00532-x. ISSN 1471-003X.
  16. ^ Nakamura, Kazuhiro; Morrison, Shaun F (January 2008). "A thermosensory pathway that controls body temperature". Nature Neuroscience. 11 (1): 62–71. doi:10.1038/nn2027. ISSN 1097-6256. PMC 2423341. PMID 18084288.
  17. ^ Yahiro, Takaki; Kataoka, Naoya; Nakamura, Yoshiko; Nakamura, Kazuhiro (10 July 2017). "The lateral parabrachial nucleus, but not the thalamus, mediates thermosensory pathways for behavioural thermoregulation". Scientific Reports. 7 (1). doi:10.1038/s41598-017-05327-8. ISSN 2045-2322. PMC 5503995. PMID 28694517.
  18. ^ Swan, K. G.; R. E. Henshaw (March 1973). "Lumbar sympathectomy and cold acclimatization by the arctic wolf". Annals of Surgery. 177 (3): 286–292. doi:10.1097/00000658-197303000-00008. PMC 1355529. PMID 4692116.
  19. ^ Adaptations for an Aquatic Environment Archived 2 March 2009 at the Wayback Machine. SeaWorld/Busch Gardens Animal Information Database, 2002. Last accessed 27 November 2006.
  20. ^ Kanosue, K.; Crawshaw, L. I.; Nagashima, K.; Yoda, T. (2009). "Concepts to utilize in describing thermoregulation and neurophysiological evidence for how the system works". European Journal of Applied Physiology. 109 (1): 5–11. doi:10.1007/s00421-009-1256-6. PMID 19882166. S2CID 11103870.
  21. ^ Guyton, A.C.; Hall, J.E. (2006). Textbook of Medical Physiology (11th ed.). Philadelphia: Elsevier Saunders. p. 890.
  22. ^ "Heat Exhaustion: Symptoms and Treatment". WebMD. Retrieved 2025-08-07
  23. ^ Harmon, Katherine. "How Does a Heat Wave Affect the Human Body?". Scientific American. Retrieved 2025-08-07
  24. ^ Harrison, G.A., Tanner, J.M., Pilbeam, D.R., & Baker, P.T. (1988) Human Biology: An introduction to human evolution, variation, growth, and adaptability. (3rd ed). Oxford: Oxford University Press
  25. ^ Weiss, M.L., & Mann, A.E. (1985) Human Biology and Behaviour: An anthropological perspective. (4th ed). Boston: Little Brown
  26. ^ "Thermoregulation". www.unm.edu. Retrieved 2025-08-07.
  27. ^ Boundless (26 May 2016). "Thermoreception". Boundless.
  28. ^ Tansey, Etain A.; Johnson, Christopher D. (2015). "Recent advances in thermoregulation" (PDF). Advances in Physiology Education. 39 (3): 139–148. doi:10.1152/advan.00126.2014. PMID 26330029. S2CID 11553866.
  29. ^ "Temperature Regulation of the Human Body". hyperphysics.phy-astr.gsu.edu. Retrieved 2025-08-07.
  30. ^ Guyton & Hall (2006), pp. 891–892
  31. ^ Wilmore, Jack H., & Costill, David L. (1999). Physiology of sport and exercise (2nd ed). Champaign, Illinois: Human Kinetics.
  32. ^ Guyton, Arthur C. (1976) Textbook of Medical Physiology. (5th ed). Philadelphia: W.B. Saunders
  33. ^ Jordán A., Juan C.; Pérez Z., José (25 June 2013). "Thermal ecology of Microlophus occipitalis (Sauria: Tropiduridae) in the Plain Dry Forest of Tumbes, Peru". Revista Peruana de Biología. ISSN 1561-0837. Archived from the original on 19 May 2022. Retrieved 9 December 2021.
  34. ^ Walker, Samantha; Stuart-Fox, Devi; Kearney, Michael R. (December 2015). "Has contemporary climate change played a role in population declines of the lizard Ctenophorus decresii from semi-arid Australia?". Journal of Thermal Biology. 54: 66–77. Bibcode:2015JTBio..54...66W. doi:10.1016/j.jtherbio.2014.12.001. PMID 26615728.
  35. ^ a b Minorsky, Peter V. (May 2003). "The Hot and the Classic". Plant Physiol. 132 (1): 25–26. doi:10.1104/pp.900071. PMC 1540311. PMID 12765187.
  36. ^ Plants Thermoregulation (PDF). Archived from the original (PDF) on 7 May 2012. Retrieved 24 October 2013.
  37. ^ Holdrege, Craig (2000). "Skunk Cabbage (Symplocarpus foetidus)". The Nature Institute: 12–18.
  38. ^ Kenneth A. Nagy; Daniel K. Odell & Roger S. Seymour (December 1972). "Temperature Regulation by the Inflorescence of Philodendron". Science. 178 (4066): 1195–1197. Bibcode:1972Sci...178.1195N. doi:10.1126/science.178.4066.1195. PMID 17748981. S2CID 8490981.
  39. ^ Gibernau, Marc; Barabé, Denis (2000). "Thermogenesis in three Philodendron species (Araceae) of French Guiana" (PDF). Canadian Journal of Botany. 78 (5): 685. Bibcode:2000CaJB...78..685G. doi:10.1139/b00-038. Archived from the original (PDF) on 4 March 2005.
  40. ^ Westhoff, Jacob (9 October 2014). "Behavioural thermoregulation and bioenergetics of riverine smallmouth bass associated with ambient cold-period thermal refuge". Ecology of Freshwater Fish. 25: 72–85. doi:10.1111/eff.12192.
  41. ^ Adela Suliman (12 August 2022). "What does 'splooting' mean? And why are New York's squirrels doing it?". Washington Post. Retrieved 12 August 2022.
  42. ^ Arends, A; Bonaccorso, FJ; Genoud, M (1995). "Basal rates of metabolism of nectarivorous bats (Phyllostomidae) from a semiarid thorn forest in Venezuela". J. Mammal. 76 (3): 947–956. doi:10.2307/1382765. JSTOR 1382765.
  43. ^ Brown, C. R.; Foster, G. G. (1992). "The thermal and energetic significance of clustering in the speckled mousebird, Colius striatus". Journal of Comparative Physiology B. 162 (7): 658–664. doi:10.1007/BF00296648. S2CID 23969182.
  44. ^ Ancel A, Visser H, Handrich Y, Masman D, Le Maho Y (1997). "Energy saving in huddling penguins". Nature. 385 (6614): 304–305. Bibcode:1997Natur.385..304A. doi:10.1038/385304a0. S2CID 45614302.
  45. ^ Canals, M; Rosenmann, M; Bozinovic, F (1989). "Energetics and geometry of huddling in small mammals". J. Theor. Biol. 141 (2): 181–189. Bibcode:1989JThBi.141..181C. doi:10.1016/S0022-5193(89)80016-5. PMID 2632987.
  46. ^ Ehmann, H; Swan, G; Swan, G; Smith, B (1991). "Nesting, egg incubation and hatching by the heath monitor Varanus rosenbergi in a termite mound". Herpetofauna. 21: 17–24.
  47. ^ Knapp, CR; Owens, AK (2008). "Nesting Behavior and the Use of Termitaria by the Andros Iguana (Cyclura Cychlura Cychlura)". Journal of Herpetology. 42 (1): 46–53. doi:10.1670/07-098.1. S2CID 86221541.
  48. ^ Briscoe, Natalie (2014). "Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals". Biology Letters. 10 (6). Royal Society. doi:10.1098/rsbl.2014.0235. PMC 4090547. PMID 24899683.
  49. ^ Harding, J.H.; Mifsud, D.A. (2017). Amphibians and Reptiles of the Great Lakes Region, Revised Ed. Great Lakes Environment. University of Michigan Press. p. 15. ISBN 978-0-472-05338-4. Retrieved 28 July 2023.
  50. ^ Kenneth S. Hagen (1962). "Biology and ecology of predaceous Coccinellidae". Annual Review of Entomology. 7: 289–326. doi:10.1146/annurev.en.07.010162.001445.
  51. ^ Bob Moore (29 September 2009). "Estivation: The Survival Siesta". Audubon Guides. Archived from the original on 21 November 2018. Retrieved 24 October 2013.
  52. ^ F.H. Pough; R.M. Andrews; J.E. Cadle; M.L. Crump; A.H. Savitzky; K.D. Wells (2001). Herpetology, second edition. Upper Saddle River, New Jersey: Prentice Hall.
  53. ^ Starr, Cecie (2005). Biology: Concepts and Applications. Thomson Brooks/Cole. pp. 639. ISBN 978-0-534-46226-0. cold temperatures birds minimize heat loss.
  54. ^ Weintraub, Karen (April 2020). "Are Human Body Temperatures Cooling Down?". Scientific American. Retrieved 10 March 2022.
  55. ^ Wong, Lena; Forsberg, C; Wahren, LK (2005). "Temperature of a Healthy Human (Body Temperature)". Scandinavian Journal of Caring Sciences. 16 (2): 122–128. doi:10.1046/j.1471-6712.2002.00069.x. PMID 12000664. Archived from the original on 26 September 2010. Retrieved 24 October 2013.
  56. ^ Rectal, ear, oral, and axillary temperature comparison. Yahoo Health. Archived from the original on 8 July 2007. Retrieved 7 March 2007.
  57. ^ Deepti Chaturvedi; K.Y. Vilhekar; Pushpa Chaturvedi; M.S. Bharambe (17 June 2004). "Comparison of Axillary Temperature with Rectal or Oral Temperature and Determination of Optimum Placement Time in Children" (PDF). Indian Pediatrics. 41 (6): 600–603. PMID 15235167.
  58. ^ Quintana, E.C. (June 2004). "How reliable is axillary temperature measurement?". Annals of Emergency Medicine. 43 (6): 797–798. doi:10.1016/j.annemergmed.2004.03.010.
  59. ^ Simpson, S; Galbraith, J. J (1905). "An investigation into the diurnal variation of the body temperature of nocturnal and other birds, and a few mammals". The Journal of Physiology. 33 (3): 225–238. doi:10.1113/jphysiol.1905.sp001124. PMC 1465744. PMID 16992810.
  60. ^ Swedan, Nadya Gabriele (2001). Women's Sports Medicine and Rehabilitation. Lippincott Williams & Wilkins. p. 149. ISBN 978-0-8342-1731-7.
  61. ^ Nakamura, Yoshiko; Yahiro, Takaki; Fukushima, Akihiro; Kataoka, Naoya; Hioki, Hiroyuki; Nakamura, Kazuhiro (23 December 2022). "Prostaglandin EP3 receptor–expressing preoptic neurons bidirectionally control body temperature via tonic GABAergic signaling". Science Advances. 8 (51). doi:10.1126/sciadv.add5463. ISSN 2375-2548. PMC 9788766.
  62. ^ Cromie, William J. (2002). Meditation changes temperatures: Mind controls body in extreme experiments. {{cite book}}: |work= ignored (help)
  63. ^ "OMIM entry on human UnCoupling Protein 2 (UCP2)". Online Mendelian Inheritance in Man.
  64. ^ a b c Simpson S, Herring PT (9 May 1905). "The effect of cold narcosis on reflex action in warm-blooded animals". J. Physiol. 32 (5 Suppl 8): 305–11. doi:10.1113/jphysiol.1905.sp001084. PMC 1465681. PMID 16992777.
  65. ^ a b c d Chisholm 1911, p. 50.
  66. ^ Foster, M. (1889). A Text Book of Physiology. Macmillan and Company. p. 818. Retrieved 28 July 2023.
  67. ^ Vecellio, Daniel J.; Wolf, S. Tony; Cottle, Rachel M.; Kenney, W. Larry (1 February 2022). "Evaluating the 35°C wet-bulb temperature adaptability threshold for young, healthy subjects (PSU HEAT Project)". Journal of Applied Physiology. 132 (2): 340–345. doi:10.1152/japplphysiol.00738.2021. ISSN 8750-7587. PMC 8799385. PMID 34913738.
  68. ^ Timperley, Jocelyn (31 July 2022). "Why you need to worry about the 'wet-bulb temperature'". The Guardian.
  69. ^ a b Federation of American Societies for Experimental Biology (FASEB) (27 April 2014). "Mite sets new record as world's fastest land animal". Featured Research. ScienceDaily. Retrieved 28 April 2014.
  70. ^ Sherwood, Van (1 May 1996). "Chapter 21: Most heat tolerant". Book of Insect Records. University of Florida. Retrieved 30 April 2014.
  71. ^ a b Harvey, Mark S.; Austin, Andrew D.; Adams, Mark (2007). "The systematics and biology of the spider genus Nephila (Araneae:Nephilidae) in the Australasian region". Invertebrate Systematics. 21 (5): 407. doi:10.1071/is05016. ISSN 1445-5226.

Further reading

[edit]
[edit]
原子序数等于什么 肌张力高有什么表现 懵的意思是什么 嗜睡是什么原因 实操是什么意思
心属于五行属什么 右腹疼是什么原因 hyq什么意思 宁静致远什么意思 赞赏是什么意思
什么时间量血压最准确 拮抗剂是什么 葛仙米是什么 司长是什么级别 随诊什么意思
女人每天吃什么抗衰老 早晨起床口苦是什么原因 甜叶菊有什么功效 懦弱的反义词是什么 蜱虫长什么样子图片
袢是什么意思naasee.com 1月15号是什么星座hcv9jop6ns6r.cn 赊事勿取是什么意思jasonfriends.com 蜈蚣泡酒有什么功效hcv7jop9ns4r.cn 便秘缺什么维生素jiuxinfghf.com
18年是什么婚weuuu.com 冷冻液是什么hcv9jop5ns8r.cn 口若悬河是什么意思hcv7jop4ns5r.cn 痔疮手术后可以吃什么水果hcv9jop2ns7r.cn 梦见自己儿子死了是什么意思wuhaiwuya.com
一什么篮子luyiluode.com 总是嗳气是什么原因96micro.com 鸡柳是什么肉hcv9jop4ns6r.cn 禁欲什么意思hcv9jop5ns8r.cn 哺乳期吃辣椒对宝宝有什么影响hcv8jop2ns7r.cn
长期胃胀是什么原因youbangsi.com 所见的意思是什么hcv8jop9ns8r.cn 牛奶有什么营养hcv8jop4ns3r.cn 麻雀长什么样hcv8jop0ns9r.cn 转氨酶高什么症状hcv8jop2ns9r.cn
百度