Microsoft PowerPoint - 08-Energy-Lecture.ppt

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1 Energy Metabolism & Body Temperature Wang LinLin M.D. Ph.D Rm 608, Block B, Research Building, School of Medicine, Zijingang Campus

2 学习要求第一节能量代谢一能量的来源转移和利用人体能量的来源, 体内能量的转移贮存和利用二能量代谢的测定食物的热价食物的氧热价和呼吸商的概念间接测热法的基本原理, 能量代谢的计算及简化测算三影响能量代谢的主要因素肌肉活动, 精神活动, 食物的特殊动力效应和环境温度四基础代谢及临床应用基础代谢和基础代谢率的概念和正常值临床上测量基础代谢率作为某些代谢异常疾病的辅助方法, 如甲状腺功能异常第二节体温及其调节一体温及其正常变动体表温度和体核温度的区别, 体温的概念和正常值体温的生理性变动, 利用此特点的临床应用, 如判断排卵期等二机体的产热与散热人体的主要产热器官和产热方式 : 战栗产热和非战栗产热, 人体的主要散热器官和散热方式, 散热过程的调节三体温调节温度感受器, 体温调节中枢, 体温调节的调定点学说讨论临床上体温异常的原因

3 Section One ENERGY METABOLISM 能量代谢 (Energy metabolism ):The metaboli c processes by which energy is made availabl e for the use of the body

4 能量的来源转移和利用 SOURCE,TRANSFER AND STORAGE OF ENERGY 能量的来源碳水化合物 Carbohydrates - mainly glucose 65 % of the total energy Glycolysis and citric acid cycle

5 脂肪 Fat fatty acids The storage of fat in the body is much greater than that of glucos e The energy liberated by oxidation of 1g of fat is 2 times that produ ced by the same amount of gluc ose

6 蛋白质 Proteins The amount of energy privided by proteins is relatively small in human being Protein will become the major energy source to maintain the essential vital activities in speci al conditions

7 能量的转化储存和利用 Heat is the end product of almost all the energy released in the body heat

8 Energy intake Energy output Energy output Performing essential metabolic functions of the body Performing various physical activities Digesting, absorbing, and processing food Maintaining body temperature

9 肥胖 obesity Leptin is reponsible for our weight Produced by fat cells( 脂肪细胞 ), leptin ( 瘦素 ) interacts with LRb to suppress appetite. The obese are not deficient in leptin, however. Instead, they appear to be insensitive to leptin, perhaps due to a mutation in LRb.

10 能量代谢的测定 Measurement of Energy Metabolism 直接测量 Direct Calorimetry

11 间接测量原理 :Energy metabolic rate = energy equivalent of oxygen oxygen consumption

12 间接测量方法 Methods of measuring CO 2 production and O 2 consumption Open circuit method Closed circuit method Closed circuit method

13 食物的热价 Thermal equivalent of food:kcal/g (kj/g) 物理热价 Physical thermal equivalent 生物热价 Biological thermal equivalent Protein: Biological thermal equivalent < Physica l thermal equivalent

14 食物的氧热价 Energy equivalent of oxygen Heat production by consuming one litre of oxygen t o oxidize a specific type of food (glucose 5.01kcal/L, fat 4.7 kcal/l, protein 4.6 kcal) 呼吸商 Respiratory quotient (RQ) The ratio of the volume of CO 2 produced to volume of O 2 consumed when a type of food is oxidized

15 The Caloric Values of Foods and the Relative Data Food Heat Production (kj/g) Physical Biological Calorie Calorie Consumpt ion of O 2 (L/g) Productio n of CO 2 (L/g) Thermal eq uivalent (kj/g) Respiratory quotient (R Q) Glucose Protein Fat

16 影响能量代谢的主要因素 Factors that affect energy metabolic rate 精神活动 Psychic activity

17 肌肉活动 Physical Activities

18 食物的特殊动力效应 Thermogenic effect of food -Specific Dynamic Action of food

19 环境温度 Environmental temperature 20 C - 30 C Cold stress Shivering thermogenesis Non- shivering thermogenesis

20 基础代谢 Basal Metabolism 人体处于基础状态下的能量代谢

21 基础代谢 Basal Metabolism 基础代谢率 Basal metabolic rate (BMR) The minimum energy expenditure for the body to exist 50-70% of the daily energy expenditure BMR is usually expressed as Calories per hour per square meter of body surface area Abnormal 20%

22 BMR 测定方法 To measure the rate of O 2 utilization under the followi ng conditions Keep fast at least for 12 hours After a night of restful sleep No strenuous activity Eliminated psychic and physical factors that cause excitement No physical activity RT: 16 to 27 C

23 影响 BMR 的因素 Gender and age

24 Thyroid hormone, male sex hormone, g rowth hormone and fever BMR Sleep and malnutrition BMR

25 Section Two BODY TEMPERATURE & REGULATION

26 体温及其正常变动 BODY TEMPERATURE AND ITS CHANGING Skin temperature Changing with the temperature of the surroundings Core temperature Maintaining constant (when T=13~54 C)

27 Normal Core temperature Site Mean Value of Temperature Standard Deviation Range of Variation of Temperature Axilla o C o C Oral cavity o C o C Rectum o C o C

28 影响体温的因素 Physiological fluctuations of the body temperature 昼夜节律 Circadian rhythm Diurnal rhythmic changes with a variation of 1 C 性别影响 Sex difference in body temperature

29 The circadian ( about a day ) rhythm of body temperature persists even among patients in a coma; in addition to this basic rhythm, fevers, exercise, and other activities can alter the body temperature.

31 Age Emotional stress Muscle activity Food, drugs

32 机体的产热与散热 HEAT PRODUCTION & HEAT LOSS Body temperature is controlled by balancing heat production against heat loss

33 产热 Heat production Major organs of heat production in the body Percentage in Body Weight Percentage at Rest Heat-production During Labor The Brain The Internal Organs (i.e. Liver and Spleen, etc.) The muscle & Skin The Others

34 产热方式 Modes of heat-production Shivering thermogenesis Non-shivering thermogenesis Control of thermogenesis Thyroxine, catecholamines, androgens an d GH Sympathetic nervous system

35 散热 Heat Loss By the skin By expiration, urination, and defecation By panting

36 How is heat lost from the skin surface? 辐射散热 Radiation: 60% Infrared heat rays Body temperature is a controlled variable that is subject to homeostatic regulation. This cartoon indicates some of the ways that environmental factors can increase or decrease body temperature.

37 How is heat lost from the skin surface? 传导散热 Conduction Conduction to solid objects Conduction to air Effect of clothing on conductive heat loss

38 How is heat lost from the skin surface? 对流散热 Convection Cooling effect of wind

39 How is heat lost from the skin surface? 蒸发散热 Evaporation A necessary cooling mechanism at very hi gh air temperature 0.58 Calorie of heat is lost for 1g water tha t evaporates

40 How is heat lost from the skin surface? 蒸发散热 Evaporation Insensible evaporation ml H 2 O/day Evaporation of sweat Sweat gland Cholinergic sympathetic nerve innervation

41 体温调节 Temperature Regulation Control of heat loss By regulation of skin blood flow By regulation of sweat glands

42 Heat Cold 温度感受器 Temperature receptors Temperature receptors in the skin Warmth receptors Cold receptors: more Deep body temperature receptors Spinal cord, abdominal viscera, great veins

43 Anterior hypothalamic-preoptic area (AH/PO) Cold-sensitive neurons Heat-sensitive neurons Serve as a thermostatic body temperature control center

44 Temperature-regulating centers In the hypothalamus Preoptic and anterior hypothalamic (P O/AH) region

45 Set point A critical body temperat ure value: 37.1 C PO/AH

46 Neuronal effector mechanisms that decrease or increase body temperature Temperature-decreasing mechani sms when the body is too hot Vasodilatation Sweating Decrease in heat production

47 Neuronal effector mechanisms that decrease or increase body temperature Temperature-increasing mechanisms when the body is too cold Skin vasoconstriction Increase in heat production Shivering (primary motor center for shivering in hypothalumus) Sympathetic excitation Thyroxine(Eskimos--higher incidence of toxic thyroid goiters)

48 Summary Terms Respiratory quotient Specific dynamic action of food Basal metabolic rate Body temperature Set-point List the factors that affect energy metabolic rate Describe the modes of heat-loss from the skin

49 Intensive Reading 基础医学教程各论 ( 上册 ) Page 652~664

脊髓损伤活动和参与的促进

脊髓损伤活动和参与的促进脊髓损伤活动和参与的促进广东省工伤康复医院作业治疗科李奎成脊髓损伤脊髓损伤 (Spinal Cord Injury, SCI) 是由各种不同伤病因素引起的脊髓结构功能的损害, 造成损害平面以下运动感觉及自主神经功能异常及相应的并发症,