1. ENERGY METABOLISM & BODY TEMPERATURE
Chapter 7
ENERGY METABOLISM & BODY TEMPERATURE
§ 1. Energy metabolism
 Introduction & definition
Substantial metabolism
Assimilation metabolism
Dissimilation metabolism (catabolism)
Energy metabolism

2.  Energy sources & utilization
* Energy sources of living organisms
Direct donator of energy: ATP
Reserve form of energy: CP
Energy sources: food
Glucose (1 mol): aerobic glycolysis yields 38 mol
ATP; anaerobic glycolysis yields 2 mol ATP
Fat: 1 mol 6C fatty acid yield 44 mol ATP
Protein: rarely used as energy donator

3. * Energy transfer & utilization
More than 50% transfer to heat,
Less than 50% store in the ATP & CP
Utilization: synthesis & growth
never conduction
muscular contraction
glandular secretion
active absorption
etc.

4. Energy source, reserve, transfer & utilization

5.  Measuring the metabolic rate
* Direct calorimetry
* Indirect calorimetry
Principle: The law of constant proportions
Several related concepts
Thermal equivalent of food
Thermal equivalent of oxygen
Respiratory quotient (RQ)
Classical & simple measurement
O2 consumption & CO2 production measuring
Closed & opened measurement

6. Thermal equivalent, Thermal equivalent of
oxygen & Respiratory quotient (RQ) of 3
main nutritional substances TE
TEO RQ
Glucose
16.7
21.0
1.00
Protein
18.8
0.80
Fat
37.7
19.7
0.71

7. Direct calorimetry

8. Indirect calorimetry

9.  Factors affecting energy metabolism
Exercises
Concept of oxygen debt
Nervous
Thinking peacefully & anxious
Food specific dynamic effect
Environmental temperature
Others: age, sex, circadian rhythm,
hormones, diseases, etc.

10.  Basal metabolism & Basal metabolic Rate (BMR)
* Definition & Law of body surface area
* Under what condition BMR can be measured?
In the Early morning
Arousal condition
Lie down peacefully with no exercises
No nervous
Have a good sleep last night
Fasting for over 12 h
Room temperature at 20~25 ℃

11. * Measurement
NPRQ=0.82; NPTEO=20.18 kJ/L;
BMR=20.18 kJ/LVo2/(m2·h) or
MV: measuring volume; SV: standard volume
* Physiological variation & clinical significances
Physiological variation: age, sex, metabolic level
Clinical significances: assistant to diagnosis of
some diseases, especially for thyroid dysfunction

12. Clinical significance of BMR

13. § 2. Body temperature & its regulation
 Normal temperature (about 37℃)
* Core & shell temperature
* Definition of body temperature in physiology
* Measurement: oral cavity, rectum, axilla, etc.
 Physiological variation of the body temperature
Circadian rhythm (biorhythm & biological
clock), Sex, Age, Emotion & Exercises,
Influences of season & district
 Skin temperature & mean skin temperature

14. Distribution of human body temperature in different environment temperature

15.  Thermogenesis & thermolysis
* Thermogenesis & its regulation
Basal metabolism, Food specific dynamic
effect, Muscular motility, Shivering &
non-shivering thermogenesis
Regulation: Thyroid & other hormones
Sympathetic nerve, NA & A
* Thermolyesis & its regulation
Radiation, Conduction & Convection
Insensible perspiration & Sweating
Regulation: Secretion of sweat
Skin circulation

16.  Regulation of body temperature
* Thermoceptor
Periphery: Cold & warm receptor
Distribute in the skin, mucosa & viscus
Center: Cold- & warm-sensitive neurons
Distribute in the spinal cord, reticular
formation of brain stem, hypothalamus,
etc., especially in the PO/AH
* Regulatory center: PO/AH
* Theory of set point

17. body temperature regulation
Autonomic control in
body temperature regulation

18. Discharge frequency of hermal sensitive neurons-temperature in local barin curve