精品课程生理学教案 第七章能量代谢与体温 [目的要求]： 1.了解食物的能量指标，能量代谢的测定： 2.掌握影响能量代谢的因素，基础代谢率及其测定。 3.掌握食物的卡价、氧热价、呼吸商、能量代谢、体温等概念 .理解影响因素对能量代谢、基础代谢、体温的作用机制及结果 [重点]： 1.食物的能量指标的几个概念： 2.影响能量代谢的因素，基础状态的概念： 3.散热的不同方式及体温调节。 [难点]： 1.食物的能量指标 2能量代谢的测定 3.体温调节。 「基本概今】： 能最代谢(e nergy etabolism):：合成代谢(anabolism,又称同化作用)：分解代诊 (catabolism,,也称异化作用)：动脉血酮体比率(arterial ketone body ratio,AKBR):能 量负荷(energy charge,简称能荷)：能量代谢率(energy metabolic rate):热价(thermal equivalent of food):卡价(caloric value):氧热t价(thermal equivalent of oxygen): 呼吸商(respiratory quotient,RO):非a蛋白呼吸商(non-protein respiratory quotient NPRQ): 食物的特殊动力效应((specific dynamic effect ):基础代谢(basa 基代谢率(basal etabolis rate,B体温():不感蒸发 (insensibleperspiration)调定点(set-point):热敏神经元(Warm-sensitive neuron): 冷敏神经元(cold-sensitive neuron):温度感受器(thermoreceptors):致热原(pyrogen): 体温调节(thermoregulation) 授课学时1.3学时 [使用教材]：王庭槐主编。生理学，第1版，高等教有出版社，2004北京 第一节能量代谢(energy metabolism) 定义：机体内伴随物质代谢过程而发生的能量的释放、转移、贮存和利用的过程。 1.新陈代谢的概念 新陈代谢：维持生命的各种活动过程中化学变化的总称」 新陈代谢包括：物质代谢（同化作用，异化作用）：能量代谢（吸热反应，放热反应） onimoigohes for
精品课程生理学教案 第七章 能量代谢与体温 [目的要求]： 1.了解食物的能量指标，能量代谢的测定； 2.掌握影响能量代谢的因素，基础代谢率及其测定； 3.掌握食物的卡价、氧热价、呼吸商、能量代谢、体温等概念； 4.理解影响因素对能量代谢﹑基础代谢﹑体温的作用机制及结果。 [重点]： 1.食物的能量指标的几个概念； 2.影响能量代谢的因素，基础状态的概念； 3.散热的不同方式及体温调节。 [难点]： 1.食物的能量指标； 2.能量代谢的测定； 3.体温调节。 [基本概念]： 能量代谢(energy metabolism)；合成代谢(anabolism，又称同化作用)；分解代谢 (catabolism，也称异化作用)；动脉血酮体比率(arterial ketone body ratio，AKBR)；能 量负荷（energy charge，简称能荷）；能量代谢率(energy metabolic rate)； 热价(thermal equivalent of food)；卡价(caloric value)；氧热价(thermal equivalent of oxygen)； 呼吸商(respiratory quotient，RQ)；非蛋白呼吸商(non-protein respiratory quotient， NPRQ)；食物的特殊动力效应(specific dynamic effect)；基础代谢(basal metabolism)； 基础代谢率 (basal metabolism rate， BMR)；体温（body temperature）；不感蒸发 （insensibleperspiration）调定点（set-point）； 热敏神经元（warm-sensitive neuron）； 冷敏神经元（cold-sensitive neuron）；温度感受器（thermoreceptors）；致热原（pyrogen）； 体温调节（thermoregulation） [授课学时]：3 学时 [使用教材]：王庭槐主编. 生理学，第 1 版，高等教育出版社，2004 北京 第一节 能量代谢（energy metabolism） 定义：机体内伴随物质代谢过程而发生的能量的释放﹑转移﹑贮存和利用的过程。 1．新陈代谢的概念 新陈代谢: 维持生命的各种活动过程中化学变化的总称。 新陈代谢包括：物质代谢（同化作用，异化作用）；能量代谢（吸热反应，放热反应） 1
图7 -1能量代谢的场所线粒体 2.能量贮 存形式 三大营养物质（糖，脂肪，蛋白质） 三羧酸循环（产生能量的方式） 图7-2三羧酸循环呼吸链 三磷酸腺苷(ATP能量的贮存形式) ATP的生成 血液 质 TP B NADH +H 图7-3ATP生成过程 3.食物的能量指标 (1)食物热价(thermal equivalent of food)：lg某种食物氧化时释放的热量。 (2)食物氧热价(thermal equivalent of oxygen)：某种食物氧化时消耗1L氧所产生的热 最。 (3)呼吸商(respiratory quotient):各种供能物质氧化时产生的C0,量与0，的消耗量的比 (④非蛋白呼吸商(nonprotein respiratory quotient,NPRQ), 将一定时间内产生的CO 量和消耗0，量减去分解蛋白质产生的C02量和耗O2量，即为非蛋白质部份（糖和脂肪）氧化 产生的C02量和耗02量。一定时间内，氧化糖和脂肪产生的CO2量和耗O2量的比值，称为非 蛋白质呼吸商。 4。能量代谢的测完 (1)直接测热法(direct 热能的直接测量 calorimetry) 特殊的检测环境，测热装置复 杂，研究肥胖和内分泌系统障 碍
图 7 -1 能量代谢的场所线粒体 2．能量贮存形式 三大营养物质（糖，脂肪，蛋白质） 三羧酸循环 (产生能量的方式) 图 7 -2 三羧酸循环呼吸链 三磷酸腺苷（ATP 能量的贮存形式） 图 7–3 ATP 生成过程 3．食物的能量指标 (1)食物热价（thermal equivalent of food）：1g 某种食物氧化时释放的热量。 (2)食物氧热价（thermal equivalent of oxygen）：某种食物氧化时消耗 1L 氧所产生的热 量。 (3)呼吸商（respiratory quotient）：各种供能物质氧化时产生的CO2量与O2的消耗量的比 值。 (4)非蛋白呼吸商（nonprotein respiratory quotient, NPRQ）： 将一定时间内产生的CO2 量和消耗O2量减去分解蛋白质产生的CO2量和耗O2量，即为非蛋白质部份（糖和脂肪）氧化 产生的CO2量和耗O2量。一定时间内，氧化糖和脂肪产生的CO2量和耗O2量的比值，称为非 蛋白质呼吸商。 4．能量代谢的测定 （ 1）直接测热法（ direct calorimetry） 特殊的检测环境，测热装置复 杂，研究肥胖和内分泌系统障 碍。 2
图7-4直接测热法 (2)间接测热法(indirect calorimetry)】 遵循定比定律，测定C0产量和尿氮排出量，测定耗0量，测量装置较简单。 C6H12O6+6O2 6C02+6H20 △G=-686 kcal/mole AT ADP +P AG=-12 kcal/mole (under conditions in the cell) 2n&T8c6v%ga8296a622608 气 记致 图7-5间接测热法 图7-6时间耗氧量 5。影响能量代谢的因素 (1)肌肉活动：肌肉活动越强能量代谢越高。机体任何轻微活动都会提高代谢率，剧烈 运动时耗0，量比安静时可增加10~20倍。 (2)精神活动：精神活动越剧能量代谢越高。 (3)食物的特殊动力效应：进食后产生的额外的热量现象。蛋白质作用最强，可“额外 增加30%左右，糖、脂肪增加4一6%，混合食物为10%。它可能是肝脏处理蛋白质分 解产物时“额外”消耗的能量。 (4)环境温度：环境温度升高或降低均可使能量代谢升高。 20~30℃稳定肌肉松驰： <20℃代谢↑寒战，肌肉紧张度↑ <10℃代谢↑寒战，肌肉紧张度1 c代谢 体内化学反 速度 ,发汗。呼吸.循环机能 脂肪组 ptin)等细胞因子 基础状态：清晨，清醒，静卧，未作肌肉活动，前夜睡眠良好，测定时无精神紧张，禁食
图 7 - 4 直接测热法 （2）间接测热法（indirect calorimetry） 遵循定比定律，测定CO2产量 和尿氮排出量，测定耗O2量，测量装置较简单。 图 7-5 间接测热法 图 7 - 6 时间耗氧量 5． 影响能量代谢 强能量代谢越高。机体任何轻微活动都会提高代谢率，剧烈 量现象。蛋白质作用最强，可“额外” 低均可使能量代谢升高。 张度↑ ； , 呼吸﹑循环机能↑ （5）其 in）等细胞因子 卧，未作肌肉活动，前夜睡眠良好，测定时无精神紧张，禁食 的因素 （1）肌肉活动：肌肉活动越 运动时耗O2量比安静时可增加 10～20 倍。 （2）精神活动：精神活动越剧能量代谢越高。 （3）食物的特殊动力效应：进食后产生的额外的热 增加 30%左右，糖、脂肪增加 4－6%，混合食物为 10%。它可能是肝脏处理蛋白质分 解产物时“额外”消耗的能量。 （4）环境温度：环境温度升高或降 20～30℃ 稳定 肌肉松驰； ＜20℃ 代谢↑ 寒战，肌肉紧 ＜10℃ 代谢↑↑ 寒战，肌肉紧张度↑ ＞30℃ 代谢↑ 体内化学反应速度↑，发汗 他因素：年龄、性别、睡眠、激素。脂肪组织可分泌瘦素（lept 也参与能量代谢的调节。小分子的脑肠肽 Ghrelin 对能量平衡有调节作用。 6． 基础代谢率及其测定 基础状态：清晨，清醒，静 3
12小时以上，室温20-25℃. 基础代谢(basal metabolism)：基础状态下的代谢状况。 基础代谢率(basal metabolism rate) 基础状态下单位时间内的能量代谢 30 25 液性水肿 正常人nan 3 甲状腺肿瘤 突眼性用状腺肿 基础代谢率相对值(BMR) 图7-7甲状腺疾病患者的基础代谢与正常人基础代谢的比较 第二节体温(body temperature) 1 体温的概念 恒温动物(homeothermic animal):变温动物(poikilothermic animal) 体表温度(shel】temperature): 体核温度(core temperature) 图7-8不同环境温度下人体体温分布图 2.产热与散热 产热器官一肝脏，骨骼肌。 产热形式一战栗产热(shivering thermogenesis),骨骼肌收缩引起。 非战栗产热(non-shivering thermogenesis),代谢产热引起， 散热部位一皮肤，呼出气，尿，类。 敢热方式： (1)辐射散热(thermal radiation):人体以热射线的形式将体热传给外界。 (2)传导散热(thermal conduction)：机体的热量直接传给同它接触的较冷物体。 (3)对流散热(thermal convection)：通过同皮肤接触的空气流动将机体热量传给外界
12 小时以上，室温 20-25℃。 基础代谢（basal metabolism）：基础状态下的代谢状况。 内的能量代谢。 第二节 体温（body temperature） 1． 体温的概念 ermic animal）； 变温动物（poikilothermic animal） 2.产热与散热 ，骨骼肌。 ng thermogenesis），骨骼肌收缩引起。 。 散热部位— diation）：人体以热射线的形式将体热传给外界。 。 。 基础代谢率（basal metabolism rate）：基础状态下单位时间 图 7-7 甲状腺疾病患者的基础代谢与正常人基础代谢的比较 恒温动物（homeoth 体表温度（shell temperature）； 体核温度（core temperature） 图 7-8 不同环境温度下人体体温分布图 产热器官—肝脏 产热形式—战栗产热（shiveri 非战栗产热（non-shivering thermogenesis），代谢产热引起 皮肤，呼出气，尿，粪。 散热方式： （1）辐射散热（thermal ra （2）传导散热（thermal conduction）：机体的热量直接传给同它接触的较冷物体 （3）对流散热（thermal convection）：通过同皮肤接触的空气流动将机体热量传给外界 4
(4)蒸发散热(thermal evaporation):通过体表水份的蒸发来散失体热。 可分为：不感蒸发(insensible evaporation),以不显汗的形式蒸发机体水份 (sensible ,以汗液蒸发的形式带走热量 自主性调节(autonomic thermoregulation):增减皮肤血流量，发汗，战栗等生理调节， 行为性调节(behavioral thermoregulation):增减衣者，开电扇空调等行为。 外周和中板温度感受器： 热敏神经元(mar--sensitive neuron)：当局部组织温度升高时神经冲动的发放频率 增加 冷敏神经元(cold-sensitive neuron)：当局部组织温度降低时神经冲动的发放频率 增加。 ()在过冷环境中一冷感受器兴奋→中枢紧张性：→血管收缩1一→血流量！→散热！：另外， 产执↑，维持体温的相对稳定 (2)在炎热环境中一热感受器兴奋一中枢紧张性！一血管收缩！一血流量一散热 另外，产热！→维持体温的相对稳定。 18 w热敏神经元 全 818 冷敏神经元。 min 图？-9由下丘脑视前区导出的温度敏感神经元的放电活动 体温调定点(set-point) 视前区-下丘脑前部(PO AD设定了 个规定的体温值，即 37 体温调定点学说(set-point theory):调定点按照PO/A温度敏感神经元的工作特性 来调节体温的高低。 温度感委装理 《反储检器
（4）蒸发散热（thermal evaporation）：通过体表水份的蒸发来散失体热。 可分为：不感蒸发（insensible evaporation），以不显汗的形式蒸发机体水份。 3.体温调 （autonomic thermoregulation）：增减皮肤血流量，发汗，战栗等生理调节。 外 nsitive neuron）：当局部组织温度升高时神经冲动的发放频率 增加 神经元（cold-sensitive neuron）：当局部组织温度降低时神经冲动的发放频率 增加 环境中→冷感受器兴奋→中枢紧张性↑→血管收缩↑→血流量↓→散热↓；另外， →中枢紧张性↓→血管收缩↓→血流量↑→散热↑ 图 7-9 由下丘脑视前区导出的温度敏感神经元的放电活动 体温调定点 的体温值，即 37℃ 调定点学说 (set-point theory)：调定点按照 PO/AH 温度敏感神经元的工作特性 来调 可感蒸发（sensible evaporation），以汗液蒸发的形式带走热量。 节 自主性调节 行为性调节（behavioral thermoregulation）：增减衣着，开电扇空调等行为。 周和中枢温度感受器: 热敏神经元（warm-se 。 冷敏 。 (1)在过冷 产热↑→维持体温的相对稳定。 (2)在炎热环境中→热感受器兴奋 另外，产热↓→维持体温的相对稳定。 （set-point）：视前区-下丘脑前部(PO/AH)设定了一个规定 。 体温 节体温的高低。 5
图7-10体温调节自动控制示意图 思考题 1.外呼吸的呼吸商与细胞呼吸的呼吸商有何异同点及联系？ 2。能用测定甲状腺激素(T,T,)的水平反映基础代谢率的高低吗？ 3.试解释人精神高度紧张时能量代谢和体温的变化过程？ 4急性发执（如定疾发作）时为何常表现出寒，高执和大汗眼挠的“三步曲” 5。试述热环境和冷环境中， 体温维持恒定的调节机制 案例：患者蔡某，35岁，工人。2天前因淋浴受凉后出现体温升高，体温达40.2℃，时有寒 颜，伴有流涕、咳嗽，诊断为普通感目，经服用阿司匹林后患者大汗淋漓，随后体温下降至 37.8℃. 请你解释为什么患者发热时有寒现象？ 2、用退热药出汗后为什么患者的体温会下降？ 3、体温的检测部位及其正常值如何？机体温度如何维持？ 参考文献 1.Hilgemann DW.1997.Cytoplasmic ATP-dependent regulation of ion transporters and channels:mechanisms and messengers(Review).Annu Rev Physiol,59:193=220. 2.Matsuzawa Y.1997.Pathophysiology and molecular mechanisms of visceral fat ese experience(Review).Diabetes Metab Rev,13(1):3-13 C.Walford Rl Harder IT.000.Energy metabolis after 2 year of energy restriction:the biosphere 2 experiment.Am J Clin Nutr,72(4):946-95. 4.Jequier E,Tappy L.1999.Regulation of body weight in humans(Review).Physiol Rev, 79(2):451-80 5.Levine IA.Eberhardt N.Jensen MD.1999.Role of nonexercise activity therogenesis in resistance to fat ain in hmansSc ,283(5399):212-214 6.Ganong WI 200L.Review of medical physiology..20thed.人民卫生出版社.271-30 7.Guyton AC,Hall JE.20O2.Textbook of medical physiology.10thed.北京医料大学出 版社.772-821 8.Nakazato M,Murakami N,Date Y,et al.2001.A role for rgrelin in the central on of feeding.Nature,40( 9.Guyton AC, Textbook of Medical Physiology.10th edition, Philadelphia:WB saunders Co. 10.Lingappa VR,Farey K.2000.Physiology medicine.New York,McGraw-Hill 11.Vander A,Sherman J,Luciano D.2001.Human Physiology.8th edition,New York, McGraw-Hill 12.Shier D.Butler J,Lewis R.1999.Hole's Hman anatomy&physiology.8th edition New York,McGraw-Hill 13.Andrew Davies,Asa G.H.Blakeley,Cecil Kidd.2001.Human Physiology. Philadelphia,WB saunders. 6
图 7-10 体温调节自动控制示意图 思考题 1. 外呼吸的呼吸商与细胞呼吸的呼吸商有何异同点及联系？ 2. 能用测定甲状腺激素（T3，T4）的水平反映基础代谢率的高低吗？ 3. 试解释人精神高度紧张时能量代谢和体温的变化过程？ 4. 急性发热（如疟疾发作）时为何常表现出寒战，高热和大汗退烧的“三步曲”。 5. 试述热环境和冷环境中，体温维持恒定的调节机制。 例：患者蔡某，35 岁，工人。2 天前因淋浴受凉后出现体温升高，体温达 40.2℃，时有寒 ，伴有流涕、咳嗽，诊断为普通感冒，经服用阿司匹林后患者大汗淋漓，随后体温下降至 .8℃。 题： 为什么患者发热时有寒颤现象？ 出汗后为什么患者的体温会下降？ 测部位及其正常值如何？机体温度如何维持？ 考文献 Hilgemann DW. 1997.Cytoplasmic ATP-dependent regulation of ion transporters and channels: mechanisms Physiol, 59:193=220. Matsuzawa Y. 1997.Pathophysiology and molecular mechanisms of visceral fat ndrome: the Japanese experience(Review). Diabetes Metab Rev, 13(1):3-13 C,Walford RL, Harder IT.2000. Energy metabolism after 2 year of energy 2(4):946-953 ew). Physiol Rev, ivity e, 283(5399):212-214 . Ganong WF. 2001.Review of medical physiology.20th ed.人民卫生出版社.271-306 to M，Murakami N，Date Y，et al. 2001.A role for rgrelin in the central ion of feeding. Nature,409(6817):194～198. of Medical Physiology. 10th edition, New York, McGraw-Hill 1.Vander A, Sherman J, Luciano D. 2001. Human Physiology. 8th edition, New York, Graw-Hill Butler J, Lewis R. 1999. Hole's Human anatomy & physiology. 8th edition, y. 案 颤 37 问 1、请你解释 2、用退热药 3、体温的检 参 1. and messengers(Review). Annu Rev 2. sy 3. Weyer restriction:the biosphere 2 experiment.Am J Clin Nutr,7 4. Jequier E,Tappy L. 1999.Regulation of body weight in humans(Revi 79(2):451-80 5. Levine JA, Eberhardt NL, Jensen MD. 1999.Role of nonexercise act therogenesis in resistance to fat gain in humans .Scienc 6 7. Guyton AC,Hall JE. 2002.Textbook of medical physiology.10th ed.北京医科大学出 版社.772-821 8. Nakaza regulat 9.Guyton AC, Hall JE. 2000. Textbook Philadelphia: WB saunders Co. 10.Lingappa VR, Farey K. 2000. Physiology medicine. 1 Mc 12.Shier D, New York, McGraw-Hill 13. Andrew Davies, Asa G.H. Blakeley, Cecil Kidd. 2001.Human Physiolog Philadelphia, WB saunders. 6
14.姚泰：生理学，第5版，人民卫生出版社，2002，ISBN7-117-03893-4 15。王庭槐主编。生理学，第1版，高等教有出版社，2004北京 Summary Metabolism is used to refer to all the chemical and energy transformation occurring in the body,which consists of material metabolism and energy metabolism.Energy metabolism refer to the production,srae,transform release and utility of ry during the process of material metabolism. The carbohydrates,fats and proteins may become the source of energy of the body.These foods can be oxidized in the cell and produced large amounts ofenergy in this process.The animal organism oxidizes carbohydrates,fats and proteins principally to CO.HO and the energy sary for life proc .It has been p inted out that drates,fats and pr ins canall be used by cells to synthesize large quantities of ATP.and that the ATP can in tur be used as an energy source for many other cellular functions.including synthesis and growth.muscular contraction,glandular secretion,nerve conduction,active absorption,etc.Energy is stored by forming high energy phosphate bonds.The ATP and the creatine phosphate contain all high energy phosphate bonds.Cre atine phosphate can transfer energy interchangeably with ATP The metaboli rate can be determined by simply measuring th he quantity of heat liberated form the body by direct or indirect methods.The metabolic rate is affected by many factors The most important one is muscular exertion.The ingested food also increases the metabolic rate After a meal containing a large quantity of carbohydrate or fat.the metabolic rate usually inreases by on about However,after a meal containing large quantity of protein,the usually increases by about3%Another factor that stimulates metabolic rate is th environmental temperature.When the environmental temperature is lower than body temperature heat-conserving mechanisms such as shivering are activated and the metabolic rate rises.When the temperature is high enough to raise the body temperature,there is a general acceleration of metabolic processes.In addition.the metabolic rate is also related to body surface area.age.sex one wth hormone et Even when a person is at complete rest,considerable energy is required to perform all the chemical reactions of the body.This minimum level of energy required to exist is called the basal metabolic rate (BMR).The measurement of the BMR provides a useful means of comparing one person's metabolic rate with that of another under basal conditions. core temperature is relatively niform in the core and regulated within narrow limits by negative feedback system.The body temperature in physiology means core temperature,1.e.,th mean temperature of deep body.In fact.the body temperature is usually indicated by the temperature in the armpit,the mouth (under the tongue)or the rectum.These values normally vary fiom36.0℃to37.4℃.or36.4℃to37.4℃.or36.9'℃to37.9 C respectivelv.Under normal body temperature afTected by usce activity and other factors,but does not nomally vary by more than1 Body temperature depends on the production and loss of body heat.The main organs of heat production in human body are the liver,the brain,the heart and the skeletal muscles.The production of heat occurs through basic metabolism and muscle activity and is controlled by
14. 姚泰：生理学，第 5 版，人民卫生出版社，2002，ISBN 7-117-03893-4 15. 王庭槐主编. 生理学，第 1 版，高等教育出版社，2004 北京 Summary Metabolism is used to refer to all the chemical and energy transformation occurring in the body, which consists of material metabolism and energy metabolism. Energy metabolism refer ydrates, fats and proteins may become the source of energy of the body. These lly to CO2, H2O and the energy ntities of ATP, and that the ATP can in turn be used as an scular ergy phosphate bonds. The ATP and the creatine phosphate contain all high energy n be determined by simply measuring the quantity of heat liberated xertion. The ingested food also increases the metabolic rate . rate usually quantity of protein, the etabolic rate usually increases by about 30%. Another factor that stimulates metabolic rate is the emperature. When the environmental temperature is lower than body temperature , mechanisms such as shivering are activated and the metabolic rate rises. When the te hen a person is at complete rest, considerable energy is required to perform all the chemi nder normal condit to the production, storage, transform, release and utility of energy during the process of material metabolism. The carboh foods can be oxidized in the cell and produced large amounts of energy in this process. The animal organism oxidizes carbohydrates, fats and proteins principa necessary for life processes. It has been pointed out that carbohydrates, fats and proteins can all be used by cells to synthesize large qua energy source for many other cellular functions, including synthesis and growth, mu contraction, glandular secretion, nerve conduction, active absorption, etc. Energy is stored by forming high en phosphate bonds. Creatine phosphate can transfer energy interchangeably with ATP. The metabolic rate ca form the body by direct or indirect methods.The metabolic rate is affected by many factors .The most important one is muscular e After a meal containing a large quantity of carbohydrate or fat, the metabolic increases by only about 4%. However, after a meal containing large m environmental t heat-conserving mperature is high enough to raise the body temperature, there is a general acceleration of metabolic processes. In addition, the metabolic rate is also related to body surface area, age, sex and hormones such as thyroid hormone, epinephrine and norepinephrine, growth hormone etc. Even w cal reactions of the body. This minimum level of energy required to exist is called the basal metabolic rate (BMR). The measurement of the BMR provides a useful means of comparing one person's metabolic rate with that of another under basal conditions. The temperature of human body includes core temperature and the shell temperature. The core temperature is relatively uniform in the core and is regulated within narrow limits by a negative feedback system. The body temperature in physiology means core temperature, i.e., the mean temperature of deep body. In fact, the body temperature is usually indicated by the temperature in the armpit, the mouth (under the tongue) or the rectum. These values normally vary from 36.0℃ to 37.4℃, or 36.4℃ to 37.4℃, or 36.9℃ to 37.9℃ respectively. U ions, the body temperature is easily affected by day and night, sex, age, muscle activity and other factors, but does not normally vary by more than 1℃. Body temperature depends on the production and loss of body heat. The main organs of heat production in human body are the liver, the brain, the heart and the skeletal muscles. The production of heat occurs through basic metabolism and muscle activity and is controlled by 7
neural and humoral factors.The heat is lost largely through the skin.The volume of heat loss from the body depends mainly upon the differences in temperature between the skin and the processes radiation,conduction,convection and evaporation.Sweating is an active secretion of water by sweat gland,which removes heat from the skin as it evaporates.The main sweating control centre is located in hypothalamus. Themoregulation thermoreguation and behavioral themoreguation receive cold or hot stimuli.The information converges to the nervous center,especially PO/AH in hypothalamus.The efferent impulse results in the production or loss of the heat so as to regulate the body temperature
neural and humoral factors. The heat is lost largely through the skin. The volume of heat loss from the body depends mainly upon the differences in temperature between the skin and the surroundings. The flow of blood to the vessels in the skin controlled by sympathetic nerves can regulate the skin temperature. Skin loses heat to the external environment by means of four processes :radiation, conduction, convection and evaporation. Sweating is an active secretion of water by sweat gland, which removes heat from the skin as it evaporates. The main sweating contro s center, especially PO/AH in hypot l centre is located in hypothalamus. Thermoregulation includes autonomic thermoregulation and behavioral thermoregulation. Thermoreceptors are divided into peripheral thermoreceptors and central thermoreceptors, which receive cold or hot stimuli. The information converges to the nervou halamus. The efferent impulse results in the production or loss of the heat so as to regulate the body temperature. 8