1. Unit Five: The Body Fluids and Kidneys
Chapter 25: The Body Compartments: Extracellular and Intracellular Fluids; Edema
Guyton and Hall, Textbook of Medical Physiology, 12th edition

2. Balance of Fluid Intake and Output
Steady-State Balance
Daily intake of water
Daily loss of water-insensible water loss
Fluid loss in sweat
Water loss in feces
Water loss by the kidneys

3. Prolonged Heavy Exercise
Table Daily Intake and Output of Water (ml/day)
Normal
Prolonged Heavy Exercise
Intake
Fluids ingested
2100 ?
From metabolism
200
Total Intake
2300
Output
Insensible-skin
350
Insensible-lungs
650
Sweat
100
5000
Feces
Urine
1400
500
Total Output
6600

4. Body Fluid Compartments
Fig Summary of body fluid regulation, including the major body fluid compartments

5. Compartments (cont.)
Body Fluid Compartments
Intracellular
Extracellular-interstitial fluid and blood plasma
Transcellular-fluids in the synovial, peritoneal,
pericardial, intraocular spaces, and the CSF
Total body water for men is about 60% and 50%
for women
e. Varies with age, gender, and degree of obesity

6. Compartments (cont.)
Intracellular Fluid Compartment
Constitutes about 40% of the fluid in the average
person
Concentration of substances is similar from cell
to cell

7. Compartments (cont.)
Extracellular Fluid Compartment
Interstitial fluid-makes up about 75% of the fluid
Blood plasma-makes up 25% of the fluid
Only real difference between the two types is the
protein composition of the plasma

8. Blood Volume
Blood Volume
Makes up about 7% of the body weight (5 L)
60% plasma and 40% cells
Percentages vary according to gender, weight, etc.
Hematocrit
Red blood cell fraction of the blood
96% accurate because you cannot pack the cells
completely
c. Males (o.40) and females (o.30)

9. Constituents of Extra- and Intracellular Fluids
Fig Major cations and anions of intracellular and
extracellular fluids.
Fig Nonelectrolytes of the plasma

10. Constituents of Extra- and Intracellular Fluids
Table Osmolar substances in extracellular and intracellular fluids
Plasma (mOsm/L of Water
Interstitial (mOsm/L of Water
Intracellular (mOsm/L of Water
Sodium
142
139 14
Potassium
4.2
4.0
140
Calcium
1.3
1.2
Magnesium
0.8
0.7 20
Chlorine
108 4
Bicarbonate 24
28.3 10
Phosphate 2 11
Sulfate
0.5 1
Phosphocreatine 45
Carnosine
Amino acids 8

11. Constituents of Extra- and Intracellular Fluids
Table Osmolar substances in extracellular and intracellular fluids
Plasma (mOsm/L of Water
Interstitial (mOsm/L of Water
Intracellular (mOsm/L of Water
Creatine
0.2 9
Lactate
1.2
1.5
ATP 5
Hexose monophosphate
3.7
Glucose
5.6
Protein 4
Urea
Others
4.8
3.9 10
Total mOsm/L
301.8
300.8
301.2
Corrected osmolar activity
282
281
Total Osmotic Pressure (37 C)
5443
5423

12. Basic Principles of Osmosis and Osmotic Pressure
Osmosis is the net diffusion of water across a selectively permeable membrane from a region of high water concentration to one that has a lower water concentration.
Rate of diffusion of water is called the rate of osmosis.

13. Moles vs. Osmoles
Osmoles-the total number of particles in a solution
One osmole is equal to 1 mole of solute particles
Osmole refers to the number of osmotically active
particles in a solution rather than to the molar
concentration

14. Osmolality vs. Osmolarity
Osmolality = osmoles/kg of water
Osmolarity = osmoles/L of solution

15. Osmotic Equilibrium
Isotonic-occurs if the water concentration of both intra-
cellular and extracellular fluid is the same; cells do
shrink or swell
Hypotonic-occurs if the water concentration is lower
inside the cell (solutes are higher inside) and
the cell will swell and possibly lyse
Hypertonic-occurs if the water concentration is
higher inside the cell (solutes are lower inside)
and the cell shrivels (crenates); water flows out
of the cell

16. Fig. 25.5 Effects of isotonic, hypotonic, and hypertonic solutions on cell volume

17. Equilibrium (cont.)
Isosmotic-solutions with an osmolarity the same as the cell
Hyperosmotic-solutions with a higher osmolarity
Hyposmotic-solutions with a lower osmolarity

18. Volume and Osmolality in Abnormal States
Effect of adding saline to extracellular fluid
Hyponatremia
Hyperantremia

19. Edema
Intracellular Edema
Hyponatremia
Depression of metabolic systems of tissues
Lack of adequate nutrition to the cells
Extracellular Edema
Abnormal leakage of fluid from plasma
Failure of the lymphatics to return the fluid
(lymphedema)