Question 1

Which of the following best describes the principle of mass balance as it relates to fluid and electrolyte homeostasis?

Accepted Answer

The amount of water and electrolytes gained by the body must equal the amount lost.

Question 2

A patient is given an intravenous solution of pure water. What is the most likely consequence for their cells?

Accepted Answer

Cells will gain water and swell due to hypotonic extracellular fluid.

Question 3

Which equation correctly represents the dissociation of carbonic acid in water?

Accepted Answer

$$\mathrm{H_2CO_3 \rightarrow H^+ + $$HCO_3$$^-}$$

Question 4

A patient with severe burns is at risk for hyperkalemia. Which of the following best explains why?

Accepted Answer

Cellular damage releases potassium ions into the extracellular fluid.

Question 5

Which hormone is most important for regulating water reabsorption in the kidneys?

Accepted Answer

Antidiuretic hormone (ADH)

Question 6

A patient presents with hyponatremia and cerebral edema. What is the most appropriate initial treatment?

Accepted Answer

Administer hypertonic saline to draw water out of the cells.

Question 7

Which of the following best describes the effect of aldosterone on electrolyte balance?

Accepted Answer

It increases sodium ion reabsorption and potassium ion secretion.

Question 8

Which buffer system is most important in the cytosol and kidney tubule filtrate?

Accepted Answer

Phosphate buffer system

Question 9

During metabolic acidosis, which compensatory mechanism is most likely to occur first?

Accepted Answer

Hyperventilation to decrease carbon dioxide and hydrogen ions

Question 10

Which of the following equations represents the relationship between pH and hydrogen ion concentration?

Accepted Answer

$$\mathrm{pH = -\log_{10}[H^+]}$$

Question 11

A patient with hypovolemia due to blood loss should be treated with which type of intravenous fluid?

Accepted Answer

Isotonic saline

Question 12

Which of the following is a fixed acid that must be eliminated by the kidneys?

Accepted Answer

Lactic acid

Question 13

What is the effect of hypercalcemia on neuronal activity?

Accepted Answer

Neurons become less permeable to sodium ions, decreasing their activity.

Question 14

Which of the following best explains why the concentration of sodium ions in the blood changes with the amount of water in the body?

Accepted Answer

The percentage of sodium ions relative to water molecules changes as water is gained or lost.

Question 15

Which of the following is NOT a function of calcium ions in the body?

Accepted Answer

Synthesis of hemoglobin

Question 16

A patient with metabolic alkalosis due to prolonged vomiting will most likely exhibit which compensatory response?

Accepted Answer

Hypoventilation to retain carbon dioxide and increase hydrogen ions

Question 17

Which of the following best describes the effect of antidiuretic hormone (ADH) on urine production?

Accepted Answer

ADH decreases urine production by increasing water reabsorption.

Question 18

Which of the following is the most abundant intracellular cation?

Accepted Answer

Potassium

Question 19

Which of the following is a primary effect of acidosis on the nervous system?

Accepted Answer

Depression of neuronal activity, leading to drowsiness and unresponsiveness

Question 20

Which equation represents the formation of carbonic acid from carbon dioxide and water?

Accepted Answer

$$\mathrm{CO_2$ + H_2O \rightarrow H_2CO_3}$$

Fluid, Electrolyte, and Acid-Base Homeostasis: Study Notes

Study Guide - Practice Questions