Chapter 24: Fluid and Electrolyte Homeostasis and Imbalances

Chapter 24: Fluid and Electrolyte Homeostasis and Imbalances

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE
1. Osmoreceptors located in the hypothalamus control the release of
a. angiotensin.
b. atrial natriuretic peptide.
c. aldosterone.
d. vasopressin (antidiuretic hormone, ADH).
ANS: D
Factors that increase secretion of ADH into the blood include increased osmolality of the blood, which is sensed by osmoreceptors
in the hypothalamus. Release of angiotensin, atrial natriuretic peptide, and aldosterone is not controlled by osmoreceptors in the
hypothalamus.
REF: Pg. 522
2. Decreased neuromuscular excitability is often the result of
a. hypercalcemia and hypermagnesemia.
b. hypomagnesemia and hyperkalemia.
c. hypocalcemia and hypokalemia.
d. hypernatremia and hypomagnesemia.
ANS: A
Hypercalcemia and hypermagnesemia result in decreased neuromuscular excitability. Hypomagnesemia, hypocalcemia, and
hypomagnesemia result in increased neuromuscular excitability.
REF: Pgs. 531-533
3. What is likely to lead to hyponatremia?
a. Insufficient ADH secretion
b. Excess aldosterone secretion
c. Administration of intravenous normal saline
d. Frequent nasogastric tube irrigation with water
ANS: D
Sodium is lost from gastric secretions when nasogastric tubes are irrigated with water. The sodium diffuses into the irrigating water
and is then lost when the aspirate is withdrawn. Excessive ADH would lead to hyponatremia by retention of water in the body, thus
diluting the sodium. Excess aldosterone would increase serum sodium. Normal saline is an isotonic solution and will not alter the
serum sodium.
REF: Pgs. 524-525
4. An increase in the resting membrane potential (hyperpolarized) is associated with
a. hypokalemia.
b. hyperkalemia.
c. hypocalcemia.
d. hypercalcemia.
ANS: A
Hypokalemia increases the resting membrane potential. Hyperkalemia results in hypopolarization. Hypocalcemia and hypercalcemia
do not affect the resting membrane potential.
REF: Pg. 530
5. Abnormalities in intracellular regulation of enzyme activity and cellular production of ATP are associated with
a. hyponatremia.
b. hypocalcemia.
c. hypophosphatemia.
d. hypokalemia.
ANS: C
Phosphate is an important component of ATP. Hypophosphatemia results in decreased ATP to cells. Hyponatremia, hypocalcemia,
and hypokalemia do not affect ATP production.