Chapter 25: Body Fluid Compartments; Edema

Question 0

Amount of insensible water loss under normal conditions.

Answer 0

700 ml/day

Question 1

Major sources of daily water intake.

Answer 1

Ingestion (2100 ml/day)

Synthesis in the body by CHO oxidation (200 ml/day)

Question 2

Insensible water loss through the skin occurs independently of sweating. True/False

Answer 2

True

Question 3

This minimizes the average water loss by diffusion through the skin acting as a barrier.

Answer 3

Cholesterol-filled cornified layer of skin

Question 4

When cornified layer of skin becomes denuded during burns, rate of evaporation can increase by how much?

Answer 4

10-fold or 3-5 L/day

Question 5

What explains the dry feeling in the respiratory passages in cold weather?

Answer 5

Nearly 0 atmospheric vapor pressure (less than the 47mmHg vapor pressure) promoting greater loss of water through the lungs with respiration.

Question 6

Total body water composition in the following:

• average 70-kg adult man
• women
• premature and NB babies

Answer 6

• 60%
• 50%
• 70-75%

Question 7

Percentage distribution of body water in both ICF and ECF

Answer 7

ICF 40%

ECF 20%

Question 8

Distribution of water in the interstitial fluid and plasma

Answer 8

Interstitial fluid - more than 3/4 of ECF

Plasma - almost 1/4 of ECF

Question 9

Fraction of blood composed of RBCs

Answer 9

Hematocrit

Question 10

Normal Hct for males and females

Answer 10

40% - males

36% - females

Question 11

Most important difference between plasma and interstitial fluid

Answer 11

High concentration of PROTEIN in the plasma

Question 12

Donnan Effect

Answer 12

Greater composition of cations in plasma than Interstitial fluid because plasma CHONs have a net negative charge. It attracts positive ions and repels negative ions.

Question 13

Indicators for measurement of:
Total body water
ECF
ICF
Plasma volume
Blood Volume
Interstitial Fluid

Answer 13

TBW - radioactive water (tritium), heavy water (deuterium), antipyrine
ECF - radioactice Na, Cl, thiosulfate, iothalamate, inulin
ICF- TBW-ECF
plasma - radioactive iodine in albumin, evans blue dye
Blood volume - Radioactive Cr
IF - ECF-plasma

Question 14

van’t Hoff’s Law

Answer 14

Used to calculate the potential osmotic pressure of a solution, assuming that the cell membrane is impermeable to the solute

Question 15

Solutions which are important in clinical medicine bec they can be infused into the blood without the danger of upsetting osmotic equilibrium between the ICF and ECF. Give an example.

Answer 15

Isotonic Solution. 0.9% NaCl or 5% glucose solution

Question 16

Effect of isotonic saline solution to ECF compartment

Answer 16

Increase ECF volume

Question 17

Effect of adding hypertonic solution to the ECF

Answer 17

Increase Extracellular and intracellular osmolarity
Increase ECF volume
Decrease ICF volume

Question 18

Effect of adding hypotonic solution to ECF

Answer 18

Increase ICF and ECF volume

Decrease IC and EC Osmolarity

Question 19

When glucose and other solutions are administered IV, what is done to prevent the upset of the osmotic equilibrium of the body fluids?

Answer 19

Concentration of the substances are adjusted to isotonicity;

Given slowly

Question 20

Normal plasma Sodium concentration

Answer 20

142 meq/L

Question 21

Decreased Na concentration, decreased ECF volume and increased ICF volume leads to what condition? give specific examples for this.

Answer 21

Hyponatremia–dehydration

Diarrhea, Addison’s dse., Vomiting And Overuse of diuretics (DAVAO)

Question 22

Hyponatremia-Overhydration causes a decrease in plasma Na concentration, increase in ECF volume and increase in IVF volume. Give cases which results to this condition.

Answer 22

Excess ADH (SIADH); 
Bronchogenic tumors

Question 23

The most common electrolyte disorder encountered in clinical practice and may occur in up to 15-25% of hospitalized patients.

Answer 23

Hyponatremia

Question 24

Increased plasma Na concentration, decreased ECF vol and decreased ICF vol causes what condition? Give causes for this abnormality.

Answer 24

Hypernatremia-dehydration

Diabetes Insipidus; excessive sweating

Question 25

Increased plasma Na concentration, increased ECF vol and decreased ICF vol leads to what condition? Give causes for this abnormality.

Answer 25

Hypernatremia-Overhydration

Cushing’s dse; primary aldosteronism

Question 26

3 causes of intracellular edema.

Answer 26

Hyponatremia
Depression of metabolic systems of the tissues
Lack of adequate nutrition to cells

*inflammation may also cause intracellular edema

Question 27

Two general causes of extracellular edema

Answer 27

Abnormal leakage of fluid from plasma to interstitial spaces across capillaries
Lymphedema

Question 28

Most common clinical cause of interstitial fluid accumulation

Answer 28

Excessive capillary fluid filtration

Question 29

Two causes that Liver Cirrhosis may lead to edema / ascites

Answer 29

• failure to produce plasma proteins (dec plasma colloid osmotic p.)
• blockage of portal venous drainage vessels by liver fibrosis (inc capillary hydrostatic p.)

Question 30

Safety factors that prevent edema

Answer 30

• low compliance of interstitium when interstitial fluid pressure is in the negative range (3 mmHg)
• 10-50 fold increase of lymph flow (7 mmHg)
• washdown of interstitial fluid protein concentration (7mmHg)

Question 31

Pitting edema occurs in which fluid compartment?

Answer 31

ECF

Question 32

Type of edema occurring when tissue cells swell or when interstitium becomes becomes clotted with fibrinogen

Answer 32

Nonpitting

Question 33

Importance of proteoglycan filaments in the interstitial spaces

Answer 33

• acts as spacer between cells

- prevent fluid from flowing too easily through tissue spaces

Question 34

Total safety factor against edema

Answer 34

17 mmHg

Question 35

Edema in the potential space / transcellular fluid compartment

Answer 35

Effusion