Substance & Energy exchange

1. Substance &
energy exchange.

2. Substance & energy
exchange
Anabolism – biosynthesis of complex
substances of the cell
Catabolism - breakdown of complex
molecules to form simple substances

3. metabolism
Food
P. F. C.
catabolism
Phosphoglycerate,
piryvate.
Anabolism
biosynthesis
work
Amino acids, nucleotides,
hormones
Growth,
development,
Structure
renewal
Cell membranes,
organels, proteins,
Nucleic acids

4. PROTEINS FATS CARBOHYDRATES
BIOLOGYCAL OXYDATION
Н2О+СО2+АТP + primary heat
Mechanical
work
Chemical synthesis,
Structure renewal
Active transport of
substances,Electrical work
Secondary heat
Active state BASAL METABOLISM

5. Sponsored
Medical Lecture Notes – All Subjects
USMLE Exam (America) – Practice

6. Basal metabolism
Total intensity of exchange
processes measured at the state
of rest

7. STANDARD CONDITIONS
TO MEASURE BASAL METABOLISM
1. IN THE MORNING (after waking up)
2. AFTER 12-16 hours FASTING
3. AT THE STATE OF PHYSICAL REST ( in
the lying posture)
4. AT THE STATE OF MENTAL &
EMOTIONAL REST
5. IN COMFORTABLE TEMPERATURE (18-
220
С for dressed body. 25-260
С for naked)

8. FACTORS INFLUENCING
BASAL METABOLISM
1. AGE
2. SEX
3. HEIGHT
4. WEIGHT
PROPER BASAL METABOLISM (TO BE
DEFINED BY THE TABLES)
WORK ALLOWANCE - energy spent
above basal metabolism to perform
work

9. Energy expenditure in different
occupations
group Peculiarities of
occupation
Quotient
of
physical
activity
Daily energy
expenditure
kcal
I Mental work 1,4 2100-2450
II Light physical
work
1,6
2500-2800
III Partially
mechanized
physical work
1,9 2950-3300
IV Heavy physical
work
2,2

10. Methods of
BIOCALORYMETRY
DIRECT BIOCALORYMETRY
INDIRECT BIOCALORYMETRY
1. GASEOUS EXCHANGE METHOD
2. DAILY DIET METHOD

11. Atwater-Benedict
BIOCALORIMETER

12. Respiratory apparatus

13. INDIRECT
IOCALORYMETRY
GASEOUS EXCHANGE
METHODRESPIRATORY QUOTIENT – RATIO
BETWEEN THE VOLUME OF СО2 RELEASED
& THE VOLUME OF О2 CONSUMED
С6Н12О6 + 6О2 = 6СО2 + 6Н2О
RQ= 6СО2/ 6О2 = 1
CALORIC VALUE OF OXYGEN – NUMBER
OF KCAL LIBERATED BY THE UTILIZATION
OF 1L OF О2

14. Duglas bag in
respiratory method

16. HEAT OF COMBUSTION VALUE OF
A NUTRIENT
– THE QUANTITY OF HEAT
PRODUCED ON COMBUSTION OF 1g
of NUTRIENT
Determined by means of Berthelot
bomb calorimeter

17. water
nutrient
termometer
Bomb
calorimeter

18. burning
1 kJ heats 1
l of water
by 0,240
С
Heated
water
water

19. Energy value of food
substances
Substance RQ CV
Kcal
Heat of
combustion
value (kcal)
PROTEINS 0,6-
0,8
4,46 - 4,8 4,1
FATS 0,7 4,7 9,3
CARBOHYDRATES 1 5,05 4,1
MIXED FOOD 0,86 4,86

21. RECOMMENDED PROPORTIONS OF NUTRIENTS

22. Dynamics of metabolism at
work
Level of О2 demand
О2 demand
О2 debt (formation)
О2 debt (paying back)
vo2
time
1 2 3

23. THERMOREGULATION

24. Homoiothermia – consistency of body
temperature, regardless of external
environment temperature changes.
Homoiothermic – are warm-blooded
animals
Poikilothermia – body temperature
depends on the external environment
temperature
Poikilothermic – are cold-blooded animals

25. «shell» - skin, adipose tissue
poikilothermic
«nucleus» - internal organs,
skeletal muscles
homoiothermic

27. Shell temperature
External environment
Тemperature, humidity, wind
Intensity of heat transport
from nucleus

28. Role of skin vessels in
termoregulation
Warm blood
Warm blood
capillaries
АVА
Cooled blood
Superficial vein
artery

29. 370
С 360
С
Physical
Termoregu
lation
Chemical
termoregu
lation
Cell
metabolism
Radiation
Convection
Conduction
Vaporation
ISOTERMIA

30. PHYSICAL
THERMOREGULATION

31. WAYS OF HEAT LOSS
1) RADIATION – heat is given off by the
skin directly into the air or to the objects
immediately in contact with its surface
(66%)
2) CONVECTION – heat release in the
process of water or air
movement(15%)

32. WAYS OF HEAT LOSS
3) CONDUCTION – heat is lost at
the contact of the body with some
substance (e.g.clothing)
4) EVAPORATION with the sweat
glands (19%)

33. External environment
factors influencing heat loss
Air temperature
Humidity
Wind

34. Regulation of heat loss
Sympathetic N.S.
(adrenergic fibers)
noradrenalin adrenoreceptors
Pre-capillary sphincters &
arterio-venous anastomoses
Changed blood flow in the skin
Changed temperature gradient

35. Regulation of heat loss
Changed temperature gradient
with environment
Changes in
radiation
convection
Heat condactance

36. Regulation of heat loss
Sympathetic N.S.
(cholinergic fibers)
acetylcholine
Sweat glands
Changes in sweat production
Sweat evaporation

37. Chemical
thermoregulation

38. Heat production
Contractile thermogenesis
Skeletal muscles
Muscle tone
Shivering
Voluntarily
movements

39. Heat production
Non-contractile thermogenesis
Fatty acids
oxidation
Glycogen
breakdown Glucone
ogenesis
Intensified
oxidation

40. Fatty acids oxidation
in newborns
Sympathetic n.s.
Brown fat –
membrane enzyme thermogenin
Cytochromic enzymes
Quick fatty
acids oxidation
heat
No ATP synthesis &
hydrolysis

41. Peculiarities of
thermoregulation in
newborns
Heat production per 1 kg of
body weight in newborns is 1,4
times higher than in adults;
Heat loss is 2 times more
intensive than in adults

42. Peculiarities of
thermoregulation in
newborns
Greater body square surface in
comparison to body weight;
More intensive blood circulation in the
skin ;
Thin skin;
In sufficient sweat evaporation.

43. Skin thermo-receptors
Cold receptors – Krause colbs -
free nerve endings in the basal layer
of epidermis.
Play important role in body
protection from overcooling.

44. Skin thermo-receptors
Warmth receptors – Ryffini bodies–
free nerve endings in the papillar
layer of epidermis.
There are a lot more of cold
receptors than warmth receptors

45. Skin thermo-receptors
Cold receptors Warmth receptors

46. Skin thermo-receptors
Cold receptors are active at –
20 tо 400
С
Warmth receptors are active
at–25 tо 470
С

47. Peripheral
thermoregulation
Protects the body from cold
Excitation of cold receptors switches on
central mechanisms enabling :
Heat production increase
Heat loss decrease

48. THERMORECEPTORS OF
BODY«NUCLEUS»
central & intravascular)
Protect the body from OVERHEATING
Excitation of «nucleus» thermoreceptors
switches on central mechanisms enabling :
INCREASED HEAT LOSS

49. HYPOTALAMUS
ANTERIOR HYPOTALAMUS –
AFFERENT SYNTHESIS OF TEMPERATURE
INFO
POSTERIOR HYPOTALAMUS–
FORMATION OF EFFERENT COMMAND

50. Neurons
receptors
Neurons
effectors
Skin temperature
Skin
termoreceptors
shell temperature
blood
CORTEX behaviour
SOMATIC N.S.
CONTRACTILE
TERMOGENESIS
Sympathetic N.S.
HYPOPHYSIS
NONCONTRACTILE
TERMOGENESIS
SKIN VESSE
EVAPORAT
Heat loss

51. HEAT LOSS
HEAT PRODUCTION
Temperature of body
«nucleus »
(homeostatic parameter)