Degree

1. METABOLISM AND ENERGY.
PHYSIOLOGY OF NUTRITION.
TERMOREGULATION.

2. Basic concepts of metabolism and
energy
• Metabolism is the main sign of life. Metabolism is
the transformation of substances and energy in the
body, as well as the exchange of substances and
energy between the body and the environment.
Living organisms need constant inflow of O2,
nutrients (proteins, fats, carbohydrates), vitamins,
mineral salts and water. Metabolism is the
interaction of 2 processes: assimilation (anabolism)
and dissimilation (catabolism). Assimilation is the
uptake, synthesis of substances, energy storage and
updating of the structures of the body.

3. • Dissimilation is the disintegration, the splitting
of substances with the release of energy, the
removal of metabolites from the body. In this
case, chemical energy is converted into
mechanical (for example, muscle contraction),
electrical (biopotentials) and thermal energy.
According to the law conservation of energy,
energy does not disappearcompletely, but
passes from one form to another. The final form
of transformation of all types of energy is
thermal energy. Therefore, the amount of heat
released by the body can be judged on the
intensity of metabolism.

4. Research methods of energy
consumption
• There are 2 methods of studying energy consumption:
direct and indirect calorimetry. The name comes from the
word calorie. Calorie (heat unit) is the amount of heat
required to heat 1 ml of water per 1degree (from 14.5 to
15.5 d). Kilocalorie (large calorie) is the amount of heat that
must be expended to heat 1 l of water per 1degree. 1
kilocalorie = 1000 calories.
• Direct calorimetry is based on the law of conservation of
energy. Body heat is captured directly in a special chamber -
biocalorimeter. The chamber is hermetically sealed and
thermally insulated from the environment. The heat
released by the body heats the water circulating through
the tubes of the chamber. How many liters of water and
how many degrees does it heat up in certain time, so much
and is allocated heat.

5. • The advantage of the method is very accurate. Disadvantages
- costly, cumbersome, time-consuming (24 hours),and, most
importantly,it does not allows us to estimate energy
expenditures in different functional states of the body (rest,
dosed load). This method can be used to quantify only the
gross (total) metabolism.
• Indirect calorimetry is based on the Hess law - the amount of
heat released by the exothermic system depends only on the
initial and final state of the system and does not depend on
the number of intermediate reactions. For example,
multistage oxidation of 1 g mol of glucose in the body first
anaerobic to lactic acid, and then aerobic to carbon dioxide
and water is accompanied by the release of 675 kcal of heat.
With a single-stage combustion of 1 g mol glucose in the
bomb Bertlow type explosion also released 675 kcal of heat.
Therefore,based on the study of gas exchange - the amount
of oxygen consumed (initial state) and the amount of carbon
dioxide released (final state), you can calculate the energy
consumption.

6. The stages of the calculation
1. Determination of respiratory coefficient- RC. RC is
the ratio of carbon dioxide released to the
amount of oxygen consumed - CO2/O2. RC is a
qualitative indicator. It shows what substances
are oxidized in the body.
• RC for carbohydrates = 1
• RC for proteins = 0.8
• RC for fats = 0.7
• RC for mixed food = 0.85 - 0.9

7. • 2. By the value of RC the caloric equivalent of
oxygen is determined from the table - CEO. CEO
is the amount of heat released during
combustion of a given substance ( or mixture of
substances) in 1 liter of oxygen.
• CEO for carbohydrates = 5,05 kcal
• CEO for proteins = 4.8 kcal
• CEO for fat = 4.7 kcal
• CEO for mixed food = 4.9 kcal

8. • 3. The amount of oxygen absorbed per day in liters
is calculated.
• 4. Energy consumption per day is calculated
• CEO x amount of oxygen (in litres) = ....
• Methods of indirect calorimetry.
• 1. Closed methods -for example, camera
Shaternikova for laboratory animals.
• 2. Open methods ( on the people): the method of
Douglas -Holden.
• Advantages of indirect calorimetry method: simple,
convenient, cheap, requires little time (10 minutes),
allows to estimate energy consumption in different
functional states (conditions of the main exchange,
dosed load). The only drawback: slightly less
accurate than direct calorimetry.

9. 3. Basal metabolism
The total (gross) metabolism consists of the basal metabolism +
working increase. Basal metabolism is the minimum level of
energy consumption the waking of the body to maintain life
processes. The energy of basal metabolism is spent on:
1. the work of breathing, blood circulation, digestion, excretion,
endocrine glands, mechanisms of neurohumoral regulation,
thermoregulation, skeletal muscle tone.
2. maintain of gradients-concentration, osmotic,hydrostatic,
electrical,chemical (on of ion pumps).
3. the processes of assimilation and dissimilation.
The basal metabolism most adequately reflects a functional
state of an organism, all mechanisms of its self-regulation.
Indicators of the basal metabolism are often taken into
account in the practice of the doctor in diagnosis and
treatment.

10. The basal metabolism is determined
under standard conditions:
1. In the waking state, since during sleep, energy expenditures
are reduced.
2. Complete rest:
physical, lying down with relaxed muscles, physical activity
significantly increases energy consumption.
mental- mental work moderately increases energy
consumption.
Emotional- emotional stress increases energy consumption.
3. On an empty stomach, 12-15 hours after eating to eliminate
specific-dynamic action of food (SDA). SDA is an increase in
energy consumption after a meal. SDA for proteins - increase
in metabolism by 30-40%. SDA for carbohydrates-10-20%.
Fats do not have SDA, and may even reduce energy
consumption. SDA begins half an hour after eating, reaches a
maximum in 6 hours, and then gradually decreases.

11. • SDA energy is spent on work of digestive organs
and mainly in the burning of excess calories. Cells
burn nutrients to their place were able to receive
new, is the renewal of cells. Neuro-humoral
regulation mechanism.
4. At comfort temperature. For dressed man-18-20
degrees, and for undressed-28-30degrees. If the
cold energy costs increases, and if it is hot - then
energy costs are reduced, because additional
mechanisms of thermoregulation are included.
5. At 7 o'clock in the morning. There are daily
biofluctuation in energy costs, the minimum
energy costs at 4 a.m. and a maximum at 16-18
p.m.

12. RATES (INDICATORS) OF BASAL METABOLISM
• An average of 1,700 kcal/day for men, 1,500 kcal for
women (10% lower) or 1 kcal/kg / hour.
• The basal metabolic rate is determined by the
indirect calorimetry method or calculated
approximately from the Harris-Benedict tables using
the Reed formula or nomogram.
• FACTORS AFFECTIN THE VALUE OF BASAL
METABOLISM.
• 1. Gender. In men higher, since more of their muscle
mass (due to the influence of androgen hormones).
• 2. Age. In children above (there is growth and
development), in adults from 20 to 40 years at a
stable level, and to old age is reduced.

13. •
• 3. Height and weight, or body surface . Rubner's rule: the
basal metabolism is directly proportional to the surface of
the body and inversely proportional to the mass of the
body. This rule has an exception. So the rabbit basal
metabolism lower than of the hare, and the wolf is higher
than that of the dog. Two similar people can also be
different. The main exchange depends on the individual
characteristics of neuro-endocrine regulation, conditions
of development and life.
• 4. Climate. The inhabitants of the North are slightly higher
than the inhabitants of the South.
• 5. Season. In winter is a little higher than in summer.
• 6. Profession. Workers heavy physical labor basal
metabolism is higher than that of the brainwork workers.
The last factors (4,5,6) change the basal metabolism of
a healthy organism only in small limits (up to 10%).

14. WORKING INCREASE
• The energy consumption of the body above basal
metabolic rate is called the working increase. The
basal metabolism + working increase-compound
gross metabolism.
• Energy costs of the working increase are
distributed:
• 1. on muscular work - spent a lot of energy
(running at 400%).
• 2. on mental work-a slight increase in energy costs
• 3. on food intake (specific dynamic effect of food)
• 4. on thermoregulation (especially in cold
conditions).

15. • There are 5 categories of people according to the size
of the working increase depending on the work activity:
• 1 category-brainworkers (students, teachers, doctors) -
2300 kcal.
• 2 category - workers of easy physical work (drivers of
public transport, teachers of physical culture, nurses
and attendants) -2800 kcal.
• 3 category - manual workers of medium gravity
(mechanics, surgeons, drivers of heavy trucks) - 3300
calories.
• 4 category - workers of heavy physical work
(metallurgists, agricultural workers, machine operators,
cotton grovers, milkmaids, sheep breeders) - 3800 kcal.
• 5 category - workers of especially heavy physical work
(miners, steelmakers, concrete workers, diggers,
loaders) - 4800 kcal.

16. • PHYSIOLOGY OF NUTRITION
• NUTRITION-the process of getting, digestion,
absorption and assimilation of nutrients.
Nutrients are proteins, fats and carbohydrates.
In addition, along with nutrients, the body
consumes water and the necessary regulatory
components, vitamins, mineral salts,
microelements.

17. The importance of nutrition:
1. Energy- sourse of energy of the body
2. Plastic (for construction and restoration of all cells
of an organism, their growth and development)
3. Regulatory-participation in self-regulation
mechanisms.
In addition, adequate nutrition provides human
health, ability to work, high creative activity, is a
good prevention of premature aging, is the basis for
the prevention and treatment of diseases.
Rational nutrition - sufficient in quantity and high-
grade in quality, that ensures optimal supply of
plastic, energy and regulatory substances necessary
for the vital activity of the body.

18. Basic principles of compiling food rations.
1. Correspondense of caloric content of food to energy
consumption of the body (energy balance of the
body). There are 5 categories of work (see above).
• The energy value of nutrients can be determined by
knowing their caloric coefficients. Caloric coefficient
is the amount of heat released in the body during
combustion of 1 gram of substance.
• Caloric coefficients
•
•
1 g protein = 4, 1 kcal,
1 g of carbohydrates = 4.1 kcal
1 g of fat = 9.3 kcal.

19. 2. Satisfaction of the body's plastic needs in
proteins, fats and carbohydrates. According to
the theory of balanced nutrition, the body
should receive the optimal amount of proteins
(protein optimum), fats and carbohydrates. For
persons of 1st and 2nd category of work this
represents an average per day 70 - 80 g protein,
60 - 80g fat and 350-400 g of carbohydrates.
3. The content in food of nutrients of animal and
vegetable origin. Consumption of proteins and
fats of animal origin not less than 50% as with
them the organism receives irreplaceable amino
and fatty acids is provided.

20. • 4. The presence in the food of the necessary
amount of mineral salts, microelements,
vitamins and water.
• 5. Accounting for food assimilability.
Assimilability depends on the digestibility of
food and the full absorption of nutrients in
digestive tract. Digestibility of food of animal
origin-95%, vegetable - 80%, mixed food - 85-
90%. To non-recyclable components of food
include ballast substances and dietary fibers
(pectin, lignin, cellulose). They play an essential
role in the motility of the digestive tract,
adsorption and removal of toxic substances.

21. • 6. Correct food regime. Food regime is a quantitative
and qualitative characteristic of food, which includes
the time of eating, its distribution during the day on
the energy value and composition, as well as the
conditions of eating. The most rational is a 4-time
meal, but in practice more often implemented 3 meals
a day. With 3 meals a day the daily calorie
requirement is distributed as follows:
• Breakfast-25-30%
• dinner - 45-50%
• supper - 20-25%.
• In addition to the above - mentioned principles,
food rations are also taken into account: gender, age,
pregnancy and lactation periods for women.

22. • HEAT EXCHANGE AND THERMOREGULATION
• The intensity of metabolic reactions is
determined by the temperature of the
enviroment, which affects the activity of all
enzymes. Temperature rise accelerates, and
temperature decrease slows down the rate of
biochemical processes.
• Thermoregulation is a complex of
physiological and psychophysiological
processes and mechanisms aimed at
maintaining the relative constancy of body
temperature.

23. • Depending on the ability to maintain constant
body temperature, all organisms are divided
into:
• 1. Homeothermal (warm blooded) and
• 2. Poikilothermic (cold-blooded).
• A man like all mammals refers to
homeothermal. The human body is able to
maintain body temperature within 1-2 degrees
Celsius, with fluctuations in ambient
temperature within a wide range.. The
constancy of body temperature is called
isothermy.

24. • The surface temperature of the body or" shell
"(skin, subcutaneous tissue and superficial
muscles) is lower than the temperature of deep
tissues - the" nucleus " (organs of the thoracic,
abdominal, pelvic cavity, as well as the brain). The
temperature of the " shell "is more susceptible to
changes than the temperature of the"core. The
temperature of the scalp and trunk is higher than
that of the limbs, in the proximal parts is higher
than in the distal, in areas covered with clothes
higher than in the nude. The tissues of the liver,
brain and kidneys are higher than in other organs.

25. • Body temperature measurement is usually
performed in:
• 1. Axillary temperature in axillary cavity is
36.5-37˚ С.
• 2. Rectal temperature in rectum is 37,2-37,5˚
C.
• 3. The oral cavity (under the tongue) oral
temperature (a bit below).

26. • Body temperature has slight variations due to
daily biorhythms (0.5-0.7 ̊ C, the minimum at 4-6
o'clock in the morning, the maximum at 18-20
o'clock in the evening), specifically dynamic action
of food, in women with the menstrual cycle.
• Body temperature is a relatively rigid homeostatic
constant of the body. The main condition of
temperature constancy is a balance or
correspondence of 2 processes: heat generation
(heat production) and heat transfer (heat release˚
).

27. • Heat production.
• Heat production is the production of heat in
the body. The formation of heat is based on
chemical exothermic reactions of metabolism.
Therefore, the regulation of heat generation is
called chemical thermoregulation.

28. Heat generation ways
Main Additional
Oxidative
processes in
tissues
Contractive
thermogenesis
non-contractive
thermogenesis

29. • At rest most of the heat is produced by the
liver, kidneys and other internal organs. During
exercise in skeletal muscle. Contractive
thermogenesis is heat generation due to
tension and contraction of skeletal muscles.
Non-contractive thermogenesis - by activating
the metabolism of brown fat, when all the
energy goes into heat (in newborns). In cold
conditions, heat production increases, and in
heat conditions decreases.

30. • Heat transfer
• Heat transfer-a set of processes aimed at the
release of heat to the environment. Heat
transfer is carried out by the surface of the
body according to the laws of physics, so the
regulation of heat transfer is called physical
thermoregulation.

31. • Ways of heat transfer:
• (at ambient temperature is 20˚C and the relative
humidity is 66%).
• 1. Heat emission-heat dissipation in the form of
infrared (thermal) rays - 66%.
• 2. Convection - loss of heat with air or water fiows. The
air in contact with the skin heats up and rises, its place
below replaces the cold and dense air - 15%.
• 3. Evaporation of water from the surface of the skin and
mucous membranes of the respiratory tract - 19%.
• 4. Carrying out the heat in contact with colder objects -
5-8%. This is usually prevent clothing with low thermal
conductivity.

32. • In severe muscular work, the role of evaporation
in the heat transfer increases. In heat conditions,
when the ambient temperature is above the
body temperature, evaporation remains the only
way to release heat to the environment. When
evaporating 1 ml of water, 0.58 kcal is then lost.
In conditions of high temperature and humidity,
evaporation is difficult and can occur
overheating of the body - hyperthermia.
• In cold conditions, the body limits the heat
transfer,and increases in heat.

33. THERMOREGULATION
• The constancy of body temperature is
maintained by neuro-reflex and humoral
mechanisms. Deviations in body temperature
are perceived by the thermoreceptors.
Distinguish thermal and cold thermoreceptors.
They are central (in the area of the anterior
hypothalamus-thermoreceptive neurons) and
peripheral (in the skin, mucous membranes,
muscles, vessels, internal organs, respiratory
tract). The main center of thermoregulation is in
the hypothalamus.

34. Thermoregulation in conditions of heat
• The increase in ambient temperatureabove the
comfortable value causes the excitation of thermal
receptors (both peripheral and central). Signals are received
in the rear hypothalamus - in the center of the heat transfer.
It is excited (at this time, the center of heat generation is
inhibited) and changes the tone of the sympathetic nerves,
which leads to the expansion of the vessels of the skin,
mucous membranes and increase the activity of the sweat
glands (increased evaporation). At the same time decrease
the metabolic processes in tissues. This is promoted by
humoral factors - decreased production of thyroid-
stimulating hormone by the anterior lobe of the pituitary
gland and thyroxine by the thyroid gland, adrenotropic
hormone by the pituitary gland and adrenaline and
noradrenaline by the adrenal glands.

35. • Along with this, the contractile thermogenesis
slows down, digestion processes slow down,
the volume of the "core" increases and the
volume of the "shell"decreases. At the
behavioral level, there are reactions: a
tendency to hypodynamy (immobility), the
desire to spread out - to increase the surface,
the motivation of thirst, a person - to get rid of
clothes.

36. • Hyperthermia-overheating of the body. The
temperature rises to 40-41˚, followed by a
thermal shock (redness of the skin, dizziness,
headache, falling of cardiac activity, respiratory
failure, nausea and vomiting, up to lose of
consciousness). The upper limit of the lethal
temperature is in the range of 43˚C.

37. • Thermoregulation in cold conditions.
• Lowering the body temperature below the
comfortable value causes the excitation of cold
thermoreceptors (peripheral and central).
• Signals arrive in a back hypothalamus-in the center
of heat generation. It is excited (at this time, the heat
transfer center is reciprocally inhibited), which leads
to increased tone of the sympathetic nervous system
and increased metabolism. This is facilitated by
humoral mechanisms. The hypothalamus activates
the anterior pituitary, after which the production of
thyrotropic and adrenocorticotropic hormones
increases, and accordingly - thyroid thyroxine and
adrenaline, noradrenaline - adrenal glands.

38. • Active turns somatic nervous system, increases
contractile thermogenesis - muscle tremors. At the
same time, the vessels of the body surface (skin,
mucous membranes, sweat glands) narrow, blood
rushes to the internal organs, which leads to a
decrease in heat transfer. Digestive processes
increase, the volume of the "core" decreases and
the volume of the "shell"increases. In animals, to
reduce heat loss in cold conditions raised hair and
increases the air-layer of hair (in humans it
manifests as a rudimentary reflex "goose skin". On
the behavioral level, there are reactions: the desire
to curl up in a ball to reduce surface, arbitrary
increasing of motor activity (running, muscle work,
etc.), search of the source of heat, the warm
clothes, warming the home.

39. • Hypothermia of the body. The temperature
decreases from 35 to 24˚C, after which there
are irreversible changes in the enzyme
systems of the body - freezing (signs of
hypothermia - falling blood pressure,heart
rate, breathing, a progressive drop in body
temperature, a state of drowsinesspassing
into deep sleep on the type of narcotic
followed by death).