26. Fluid and Electrolyte Balance, Acid Base Balance

Potassium, magnesium, and phosphate ions are the predominant electrolytes in:

a. Plasma

b. Interstitial fluid

c. Intracellular fluid

Sodium balance is regulated primarily by control of amount(s):

a. Ingested

b. Excreted in urine

c. Lost in perspiration

d. Lost in feces

Two main substances regulated by the influence of aldosterone on the kidney tubules are:

a. Ammonium ions

b. Bicarbonate

c. Calcium

d. Chloride

e. Hydrogen ions

f. Magnesium

g. Phosphate

h. Potassium

i. Sodium

j. Water

Explain why and how total body sodium content, ECF volume, and blood pressure are jointly regulated.

Explain how Na⁺ balance, ECF volume, and blood pressure are jointly regulated.

Mrs. Bush, a 70-year-old woman, is admitted to the hospital. Her history states that she has been suffering from diarrhea for three weeks. On admission, she complains of severe fatigue and muscle weakness. A blood chemistry study yields the following information: Na⁺ 142 mEq/L; K⁺ 1.5 mEq/L; Cl⁻ 92 mEq/L; Pco₂ 32 mm Hg.

Which electrolytes are within normal limits? Which are so abnormal that the patient has a medical emergency?

Which of the following represents the greatest danger to Mrs. Bush?

a. A fall due to her muscular weakness

b. Edema

c. Cardiac arrhythmia and cardiac arrest.

Which of the following is false with respect to sodium ions in human physiology?

a. Sodium ions are the most abundant extracellular cation.

b. Sodium ions are an important osmotic particle in the ECF.

c. The entry of sodium ions into a cell causes depolarization.

d. Sodium ions are more concentrated in the cytosol than in the ECF.

List the effects of each of the following hormones on electrolyte balance. Note that some hormones affect more than one electrolyte.

a. Angiotensin-II

b. Aldosterone

c. Parathyroid hormone

d. Vitamin D

e. Atrial natriuretic peptide

Which of the following effects tend to be caused by hypernatremia?

a. Inhibition of ADH secretion

b. Cellular crenation

c. Cellular swelling

d. Increased urine production

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. Potassium ions are responsible for the repolarization phase of the action potential.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. Insulin, aldosterone, and epinephrine stimulate the uptake of potassium ions into cells.