Ch 42: Agents Affecting the Volume and Ion Content of Body Fluids

Question 1

Why is sodium used as the reference for classification of fluid volume disorders?

Answer 1

Because sodium is the principal extracellular solute.

p. 459

Question 2

What are 4 possible causes of isotonic contraction?

Answer 2

vomiting, diarrhea, kidney disease, and misuse of diuretics

p. 459

Question 3

Hypertonic contraction is defined as volume contraction in which loss of water…

Answer 3

…exceeds loss of sodium.

p. 459

Question 4

Because of extracellular hypertonicity, water is drawn out of cells, thereby producing…

Answer 4

…intracellular dehydration.

p. 459

Question 5

What are 5 possible causes of hypertonic contraction?

Answer 5

(1) excessive sweating, (2) osmotic diuresis, (3) feeding excessively concentrated foods to infants.
Hypertonic contraction can develop secondary to (4) extensive burns, or (5) disorders of the CNS that impair the thirst mechanism.

(p. 459)