Chapter 7Chapter 7 ENERGY ENERGY METABOLISM & METABOLISM &

BODY BODY TEMPERATURETEMPERATURE

§ 1. § 1. Energy metabolismEnergy metabolism

Introduction & definitionIntroduction & definition

SSubstantialubstantial metabolism metabolism

Assimilation metabolismAssimilation metabolism

Dissimilation metabolism (catabolism)Dissimilation metabolism (catabolism)

EEnergy metabolismnergy metabolism

Energy sources & utilizationEnergy sources & utilization

** Energy sources of living organismsEnergy sources of living organisms

DDirect donatorirect donator of energy: ATP of energy: ATP

RReserve formeserve form of energy: CP of energy: CP

EEnergy sourcesnergy sources: food: food

GGlucoselucose (1 mol):(1 mol): aerobic glycolysis yields 38 mol aerobic glycolysis yields 38 mol

ATP; anaerobic glycolysis yields 2 mol ATPATP; anaerobic glycolysis yields 2 mol ATP

FFat: 1 mol 6C fatty acidat: 1 mol 6C fatty acid yield 44 mol ATP yield 44 mol ATP

PProtein:rotein: rarely used as energy donator rarely used as energy donator

** Energy transfer & utilizationEnergy transfer & utilization

MMore than 50% transfer to heat,ore than 50% transfer to heat,

LLess than 50% store in the ATP & CPess than 50% store in the ATP & CP

UUtilization: tilization: ssynthesis & growthynthesis & growth

nnever conductionever conduction

mmuscular contractionuscular contraction

gglandular secretionlandular secretion

aactive absorptionctive absorption

eetc.tc.

Energy Energy source, source, reserve, reserve, transfer & transfer & utilizationutilization

Measuring the metabolic rateMeasuring the metabolic rate

** Direct calorimetryDirect calorimetry

** Indirect calorimetryIndirect calorimetry

Principle: Principle: The law of constant proportionsThe law of constant proportions

Several related conceptsSeveral related concepts

TThermal equivalent of foodhermal equivalent of food

TThermal equivalent of oxygenhermal equivalent of oxygen

RRespiratory quotient (RQ) espiratory quotient (RQ)

Classical & simple measurementClassical & simple measurement

OO22 consumption & CO consumption & CO22 production measuring production measuring

Closed & opened measurementClosed & opened measurement

TETE TEOTEO RQRQ

GlucoseGlucose 16.716.7 21.021.0 1.001.00

ProteinProtein 16.716.7 18.818.8 0.800.80

FatFat 37.737.7 19.719.7 0.710.71

Thermal equivalent, Thermal equivalent of Thermal equivalent, Thermal equivalent of

oxygen & Respiratory quotient (RQ) of 3 oxygen & Respiratory quotient (RQ) of 3

main nutritional substancesmain nutritional substances

Direct calorimetryDirect calorimetry

Indirect calorimetryIndirect calorimetry

Factors affecting energy metabolismFactors affecting energy metabolism

EExercises xercises

Concept of oxygen debtConcept of oxygen debt

NNervouservous

Thinking peacefully & anxiousThinking peacefully & anxious

FFood specific dynamic effectood specific dynamic effect

EEnvironmental temperaturenvironmental temperature

OOthers: age, sex, circadian rhythm, thers: age, sex, circadian rhythm,

hormones, diseases, etc.hormones, diseases, etc.

Basal metabolism & Basal metabolic Rate Basal metabolism & Basal metabolic Rate (BMR)(BMR)

** Definition & Law of body surface areaDefinition & Law of body surface area

** Under what condition BMR can be Under what condition BMR can be measured?measured?

In theIn the EEarly morningarly morning

AArousal conditionrousal condition

LLie down ie down ppeacefully with eacefully with nono eexercisesxercises

No No nnervouservous

Have a goodHave a good s sleep last nightleep last night

FFasting for over 12 hasting for over 12 h

RRoom temperature at 20~25 ℃oom temperature at 20~25 ℃

** MeasurementMeasurement

NPRQ=0.82; NPTEO=20.18 kJ/L;NPRQ=0.82; NPTEO=20.18 kJ/L;

BMR=20.18 kJ/LBMR=20.18 kJ/LVoVo22/(m/(m22··h) orh) or

MV: measuring volume; SV: standard volumeMV: measuring volume; SV: standard volume

** Physiological variation & clinical significancesPhysiological variation & clinical significances

Physiological variation:Physiological variation: age, sex, metabolic level age, sex, metabolic level

Clinical significances:Clinical significances: assistant to diagnosis of assistant to diagnosis of

some diseases, especially for thyroid dysfunctionsome diseases, especially for thyroid dysfunction

%SV

SVMVBMR 100

Clinical significance of BMRClinical significance of BMR

§§ 2. Body temperature & its regulation 2. Body temperature & its regulation

Normal temperatureNormal temperature (about 37 )℃(about 37 )℃ ** Core & shell temperatureCore & shell temperature

** Definition of body temperature in physiology Definition of body temperature in physiology

** Measurement: oral cavity, rectum, axilla, etc. Measurement: oral cavity, rectum, axilla, etc.

Physiological variation of the body temperaturePhysiological variation of the body temperature

CCircadian rhythm (ircadian rhythm (bbiorhythm & iorhythm & bbiological iological

clock), clock), SSex, ex, AAge, ge, EEmotion & motion & EExercises, xercises,

IInfluences of season & districtnfluences of season & district

Skin temperature & mean skin temperatureSkin temperature & mean skin temperature

Distribution Distribution of human of human body body temperature temperature in different in different environment environment temperature temperature

Thermogenesis & thermolysisThermogenesis & thermolysis ** ThermogenesisThermogenesis & its regulation & its regulation BBasal metabolism, asal metabolism, FFood specific dynamicood specific dynamic effect, effect, MMuscular motility, uscular motility, SShivering & hivering & non-snon-shivering thermogenesishivering thermogenesis Regulation:Regulation: TThyroid & other hormoneshyroid & other hormones SSympathetic nerve, NA & Aympathetic nerve, NA & A ** ThermolyesisThermolyesis & its regulation & its regulation RRadiation, adiation, CConduction & onduction & CConvectiononvection IInsensible perspiration & nsensible perspiration & SSweatingweating Regulation:Regulation: SSecretion of sweatecretion of sweat SSkin circulationkin circulation

Regulation of body temperatureRegulation of body temperature

** ThermoceptorThermoceptor

Periphery:Periphery: Cold & warm receptor Cold & warm receptor

Distribute Distribute in the skin, mucosa & viscusin the skin, mucosa & viscus

Center:Center: Cold- & warm-sensitive neurons Cold- & warm-sensitive neurons

Distribute Distribute in the spinal cord, reticular in the spinal cord, reticular

formation of brain stem, hypothalamus,formation of brain stem, hypothalamus,

etc., especially in the PO/AHetc., especially in the PO/AH

** Regulatory center: Regulatory center: PO/AHPO/AH

** Theory of Theory of set pointset point

Autonomic control in Autonomic control in body temperature regulationbody temperature regulation

Discharge frDischarge frequency of hequency of hermal sensitiermal sensitive neurons-tve neurons-temperature emperature in local bariin local barin curven curve