body fluids

1. DR NILESH KATE
MBBS,MD
ASSOCIATE PROF
DEPT. OF PHYSIOLOGY
BODY FLUIDS

2. OBJECTIVES
1. Volumes & Compartments of body fluids
2. Composition of body fluids
3. Measurement of each compartment
4. Significance of body fluids.
5. Water balance – positive and negative
water balance
6. Oedema , Dehydration.
Thursday, December 10, 2015

3. BODY COMPOSITION
60%
7%
18%
15%
BODY COMPOSITION
WATER
MINERALS
PROTEINS
FATS
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4. TOTAL BODY WATER
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5. BODY FLUID COMPARTMENTS
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6. DISTRIBUTION OF TOTAL
BODYY WATER
COMPARTMENTS VOLUME (L) PERCENTAGE
BODY WEIGHT BODY WATER
TOTAL BODY
WATER
42 60 100
ICF 28 40 67
ECF 14 20 33
PLASMA (25%) 3.5 5 8
INTERSTITIAL
FLUID,
TRANSCELLULAR
FLUID,
MESENCHYMAL
TISSUE (75%)
10.5 15 25
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7. PERCENTAGE OF WATER IN THE
BODY
Total Body Water
varies depending on
body fat:
 infant: 73%
 male adult: 60%
 female adult: 40-50%
 effects of obesity
 Old age 45%

8. Thursday, December 10, 2015

9. MOVEMENT OF BODY FLUIDS
IMPORTANT CONCEPT
 Body fluids are not
static.
 Fluids & electrolytes
shift from
compartment to
compartment.
 Emphasis is always on
maintaining
homeostasis

10. COMPOSITION OF BODY FLUIDS
Body fluids contain water
and solids. Solids are
organic and inorganic
substances.
 ORGANIC SUBSTANCES:
Glucose, amino acids,
fatty acids, hormones
and enzymes.

11. COMPOSITION OF BODY FLUIDS
 INORGANIC SUBSTANCES:
Extracellular fluid contains
large quantity of sodium,
chlorides, bicarbonate,
glucose, fatty acids and
oxygen.
 Intracellular fluid
contains large quantities of
potassium, magnesium,
phosphates, sulphates and
proteins.
PH of ECF is 7.4
PH of ICF is 7

13. SIGNIFICANCE OF BODY FLUIDS
 In Homeostasis: Body
cells survive in the fluid
medium called internal
environment or milieu
interior.
 Growth and functions of
cells Glucose, amino
acids, lipids, vitamins,
ions, oxygen etc., in
proper quantities in the
internal environment.

14. SIGNIFICANCE OF BODY FLUIDS
 In Transport
mechanism: Body
water forms the
transport medium by
which nutrients and
other essential
substances enter the
cells and wastes come
out of the cells.
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15. SIGNIFICANCE OF BODY FLUIDS
 In Metabolic reactions:
water inside the cells
forms the medium for
various metabolic
reactions, which are
necessary for growth
and functional
activities of the cells.

16. SIGNIFICANCE OF BODY FLUIDS
 In Texture of tissues : water
inside the cells is
necessary for the
characteristic form and
texture of various tissues.
 In Temperature
regulation : body water
plays a vital role in the
maintenance of normal
body temperature.
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17. REGULATORY MECHANISMS
 Hypothalamus –Thirst
mechanism
 KIDNEYS
 Kidney Function
 HORMONES
 Renin-Angiotensin-
Aldosterone
 Anti-Diuretic Hormone

18. MEASUREMENT OF BODY FLUIDS
INDICATOR DILUTION METHOD:
V = M
C
V = volume of fluid in the compartment
M = Mass or total quantity of marker substance
injected
C = Concentration of the marker substances in the
sample of fluid
CORRECTED FORMULA:
Volume = Amt. of subs. Amt. of subs.
Injected - excreted
Conc. of subs. in sample of fluid.

19. PRE-REQUISITE FOR ACCURATE
BODY FLUID MEASUREMENTS
 Non-toxic.
 Mix-evenly.
 Relatively easy to
measure.
 No effect on
distribution of water.
 Must be unchanged & if
changed must be
known.
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20. MEASUREMENT OF TOTAL BODY
WATER.
 By injecting marker
which evenly
distribute in all
compartment of body.
 Markers used
 Deuterium Oxide.
 Tritium Oxide.
 Aminopyrine.
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21. MEASUREMENT OF ECF VOLUME.
 Marker should not enter the
cell but freely pass through
capillary membrane.
 Radioactive substances –
Na, Cl, Bromide sulphate,
Thiosulphate
 NON-METABOLIZABLE
saccharides – Inulin (Most
accurate) Mannitol, Sucrose
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22. MEASUREMENT OF PLASMA
VOLUME
 Marker should bind
strongly with plasma
proteins & should not
diffuse into Interstistium.
 Radioactive iodine (I121
)
 Evan’s blue dye
 Radioactive isotopes of
Chromium (Cr51
)
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23. MEASUREMENT OF ICF
 Cannot be measured
directly.
 So ICF = TBW - ECF
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24. MEASUREMENT OF
INTERSTITIAL FLUID VOLUME
 Interstitial fluid
volume =
ECF – Plasma volume.
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25. WATER BALANCE
Body fluid levels are maintained at normal
levels when the intake and output of
water are balanced.
INTAKE OUTPUT
Drinking – 1300 Urine – 1500
Food – 850 Sweat through skin - 500
Metabolic origin – 350 Feces – 100
------------ Expired air - 400
2500 ml ----------
2500ml
When the intake is more than the output then
a positive water balance develops.

26. PHYSIOLOGICAL POSITIVE
WATER BALANCE
 Growth
 Convalescence
 Pregnancy

27. PATHOLOGICAL POSITIVE WATER
BALANCE
 This is referred to as oedema.
Abnormal accumulation of
water in normally existing
space in the body is called
Oedema.
Oedema develops in
 Heart Failure
 Renal failure
 Malnutrition
 Inflammation of tissue

28. OEDEMA
Oedema is mostly extracellular and may develop
due to:
 Increase in capillary hydrostatic pressure
 Decreased colloidal osmotic pressure
 Increased permeability of the capillary
 Lymphatic obstruction
 Failure of kidney to excrete excess water

29. NEGATIVE WATER BALANCE
 PHYSIOLOGICAL NEGATIVE WATER BALANCE:
occurs during exercise, working in hot sun.
 PATHOLOGICAL NEGATIVE WATER BALANCE: is
seen in dehydration, burns, hemorrhage,
vomiting, diarrhea when the output is more
than input, negative water balance develops.

30. DEHYDRATION
Excessive loss of body
water leading to a
decline in body
water level is called
dehydration.
Dehydration may
be due to :
 Simple water loss
 Loss of both water
and electrolytes

31. DEHYDRATION -- EXCESSIVE LOSS OF
BODY WATER IS SEEN IN
 Excess body water loss as
in diarrhea
 Severe vomiting
 Excessive sweating
 Fluid loss in burns
 Addison’s disease
 Diabetes mellitus and
Diabetes insipedus
 Renal disease
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32. The clinical symptoms associated
with severe dehydration are:
 Low cardiac output
 Rapid pulse rate
 Low blood pressure
 Decreased skin turgor
 Acidosis
 Sunken eye balls
 Lethargy, confusion and
coma
 Intracellular
dehydration may lead to
death.

33. Severe Dehydration
TREATMENT:
The replenishment
of body with water
and electrolytes.
Electrolytes and pH
should be monitored
carefully.

34. BODY ELECTROLYTE
 Distribution of ions in ECF & ICF
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IONS ECF ICF
CATIONS
Na+ 142 14
K+ 5.5 150
Ca+ 5 <1
Mg+ 3 58
ANIONS
Cl- 103 4
HCO3 28 10
PO4 4 75
Proteins 5 40

35. INFERENCE
 In ICF major Cations
are K+ & Mg and
major anions PO3 &
Proteins.
 In ECF major Cations
is Na+ and major
anions are Cl- & HCO3
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36. EXCHANGEABLE IONS
 All body K+ is
exchangeable
 65-70% of Na is
Exchangeable.
 All Ca & Mg Non-
exchangeable.
 Only exchangeable
solutes – Osmotically
active.
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37. FUNCTIONS OF ELECTROLYTE.
 Main solutes for acid-
Base maintenance
balance.
 Maintain proper
osmolality & volume of
body fluids.
 Concentration of certain
determine their
physiological function.
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38. Thank you.
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