The document discusses the body's fluid compartments and fluid balance. It describes that the body has extracellular and intracellular fluid compartments, with the extracellular space consisting of plasma and interstitial fluid. Total body water is about 60% of body weight, with 20% being extracellular fluid and 40% intracellular fluid. Fluid balance is regulated to keep the osmolarities of intracellular and extracellular fluids equal. Edema occurs when there is excess fluid accumulation in the interstitial spaces, usually due to increased capillary fluid filtration from factors like increased capillary pressure, decreased plasma proteins, or increased capillary permeability.
2. The Body Fluid CompartmentsThe Body Fluid Compartments ::
Extracellular and IntracellularExtracellular and Intracellular
Fluids:Fluids:
Interstitial Fluid and EdemaInterstitial Fluid and Edema
Body Fluids and The
Kidneys
3. The maintenance of a relatively constant volume and a stableThe maintenance of a relatively constant volume and a stable
composition of the body fluids is essential for homeostasiscomposition of the body fluids is essential for homeostasis
Fluid Intake and Output are Balanced During Steady-State
Conditions
5. 1. Extracellular Fluid Compartment - 14.0 L1. Extracellular Fluid Compartment - 14.0 L
Interstitial - 11.0 L = 3/4Interstitial - 11.0 L = 3/4
Plasma - 3.0 L = 1/4Plasma - 3.0 L = 1/4
2. Extracellular Fluid Compartment = 28.0 L
3. Transcellular Fluid Compartment 1to 2 liters - includes fluid in the
following Spaces:
° Synovial
° Peritoneal
° Pericardial
° Intraocular
° Cerebrospinal fluid
6. Total Body Water is 60% of the body weight =Total Body Water is 60% of the body weight =
42 liters42 liters
Extracellular Fluid 20% = 14.0LExtracellular Fluid 20% = 14.0L
Intracellular Fluid 40% = 28.0LIntracellular Fluid 40% = 28.0L
Blood Volume
Blood contains both extracellular fluid (the fluid in the plasma)
and intracellular fluid ( the fluid in the red blood cells)
7. Constituents of Extracellular Fluid andConstituents of Extracellular Fluid and
Intracellular FluidIntracellular Fluid
8.
9. Regulation of Fluid Exchange and Osmotic
Equilibrium Between Intracellular and Extracellular
Fluid
Basic Principles of Osmosis and Osmotic Pressure
Osmotic Equilibrium is Maintain Between Intracellular Fluid
and Extracellular Fluid
11. Osmotic Equilibrium Between Intracellular and Extracellular Fluids is
Rapidly Attained
Volume and Osmolality of Extracellular Fluid in Abnormal States
Basic Principles to Calculate Changes in Intracellular and
Extracellular Fluid Volumes and Types of Therapy
1. Water moves rapidly across cell membrane; therefore the osmolarities of ICF
and ECF remain almost exactly equal to each other.
2. Cell membranes are most completely impermeable to many solutes; therefore
the number of osmoles in the ECF or ICF remain constant.
16. Causes of Hyponatremia:
- Excess Water
- Loss of Sodium
Causes of Hypernatremia:
- Water loss
- Excess of Sodium
17. EDEMA: presence of excess fluid in the body tissues
A. Intracellular Edema
A. depression of the metabolic systems of the tissues
B. lack of adequate nutrition to the cells
C. Inflammation
B. Extracellular Edema
A. abnormal leakage of fluid from the plasma to the interstitial spaces
across the capillaries
B. failure of the lymphatics to return fluid from the interstitium back into
the blood
18. The most common clinical cause of interstitial fluid accumulation is
excessive capillary fluid filtration
Factors That Can Increase Capillary Filtration
1. Increase Filtration Coefficient - product of
permeability and surface area of the capillaries ( kf )
2.Increase Capillary Hydrostatic Pressure ( Pc )
3. Decrease capillary Colloid Osmotic Pressure
( iic)
Filtration = Kf x ( Pc - Pif - iic +iiif )
19. Major Factors that cause Increased Capillary Filtration of Fluid
and Protein into the Interstitium:
1. Increased capillary Hydrostatic Pressure
2. Decreased Plasma Colloid Osmotic Pressure
3. Increased Capillary Permeability
20. Summary of Causes of Extracellular Edema
1. Increased capillary pressure
A. Excessive kidney retention of salt and water
1. Acute and chronic kidney failure
2. Mineralocorticoid excess
B. High venous pressure
1. Heart failure
2. Venous obstruction
3. Failure of venous pump
A. paralysis of muscle
B. immobilized parts of body
C. Failure of venous valves
21. C. Decreased arteriolar resistance
1. Excessive body heat
2. Insufficiency of sympathetic
nervous system
3. Vasodilator drugs
II. Decreased plasma proteins
A. Loss of proteins in urine ( nephrotic syndrome )
B. Loss of proteins from denuded skin areas
1. Burns
2. Wounds
C. Failure to produce proteins
1. Liver disease
2. Serious protein or caloric malnutrition
22. III. Increased capillary permeability
A. Immune reactions that cause release of histamine
B. Toxins
C. Bacterial infections
D. Vitamin deficiency, especially vitamin C
E. Prolonged ischemia
F. Burns
IV. Blockage of lymph return
A. Cancer
B. Infections ( filarial nematodes)
C. Surgery
D. Congenital absence or abnormality of
lymphatic vessels
23. Safety Factors That Prevent Edema
1. The safety factors caused by low tissue compliance ( -3 mmHg )
2. The safety factor caused by increased lymph flow ( 7 mmHg )
3. The safety factor caused by washdown of proteins from the
interstitial spaces ( 7 mmHg )
