Question 1

Which statements regarding total body water (TBW) are true? (Select all that apply.)
A)During childhood, TBW slowly decreases in relationship to body weight.
B)Gender has no influence on TBW until old age.
C)Men tend to have greater TBW as a result of their muscle mass.
D)Estrogen plays a role in female TBW.
E)Older adults experience a decrease in TBW as a result of decreased muscle mass.

Accepted Answer

During childhood, TBW slowly decreases to 60% to 65% of body weight. At adolescence, the percentage of TBW approaches adult proportions, and gender differences begin to appear. Men eventually have a greater percentage of body water as a function of increasing muscle mass. Women have more body fat and less muscle as a function of estrogens and therefore have less body water. With increasing age, the percentage of TBW declines further still. The decrease is caused, in part, by an increased amount of fat and a decreased amount of muscle, as well as by a reduced ability to regulate sodium and water balance.

Question 2

A third of the body's fluid is contained in the extracellular interstitial fluid spaces that include what? (Select all that apply.)
A)Urine
B)Intraocular fluids
C)Lymph
D)Blood plasma
E)Sweat

Accepted Answer

Two thirds of the body's water is in the intracellular fluid (ICF) compartment, and one third is in the extracellular fluid (ECF) compartments. The two main ECF compartments are the interstitial fluid and the intravascular fluid, such as the blood plasma. Interstitial ECF compartments include the lymph and the transcellular fluids, such as the synovial, intestinal, biliary, hepatic, pancreatic, and cerebrospinal fluids; sweat; urine; and pleural, synovial, peritoneal, pericardial, and intraocular fluids.

Question 3

In hyperkalemia, what change occurs to the cells' resting membrane potential?
A)Hypopolarization
B)Hyperexcitability
C)Depolarization
D)Repolarization

Accepted Answer

In hyperkalemia, the cells' resting membrane potential becomes more positive (i.e., changes from -90 to -80 mV) and the cell membrane is hypopolarized (i.e., the inside of the cell becomes less negative or partially depolarized).

Question 4

Physiologic pH is maintained at approximately 7.4 because bicarbonate (HCO₃) and carbonic acid (H₂CO₃) exist in what ratio?
A)20:1
B)1:20
C)10:2
D)10:5

Accepted Answer

The relationship between HCO₃ and H₂CO₃ is usually expressed as a ratio. When the pH is 7.4, this ratio is 20:1 (HCO₃:H₂CO₃). The other options do not accurately identify physiologic pH by the correct ratio of HCO₃ and H₂CO₃.

Question 5

An imbalance of potassium can produce which dysfunctions? (Select all that apply.)
A)Weakness of skeletal muscles
B)Cardiac dysrhythmias
C)Smooth muscle atony
D)Visual impairment
E)Hearing loss

Accepted Answer

Symptoms of hyperkalemia vary, but common characteristics are muscle weakness or paralysis and dysrhythmias with changes in the ECG. A wide range of metabolic dysfunctions may result from hypokalemia. Neuromuscular excitability is decreased, causing skeletal muscle weakness, smooth muscle atony, and cardiac dysrhythmias. Potassium imbalances do not produce visual or hearing problems.

Question 6

A healthcare provider notes that tapping the patient's facial nerve leads to lip twitching. What electrolyte value is correlated with this finding?
A)K⁺: 2.8 mEq/L
B)K⁺: 5.4 mEq/L
C)Ca⁺⁺: 8.2 mg/dL
D)Ca⁺⁺: 12.9 mg/dL

Accepted Answer

This patient has a positive Chvostek sign, which is indicative of hypocalcemia. The normal range of Ca⁺⁺ is 9 to 10.5 mg/dL. 12.9 mg/dL indicates hypercalcemia. Potassium imbalances are not related.

Question 7

A healthcare professional is caring for four patients. Which patient should the professional assess for hypermagnesemia as a priority?
A)Hepatitis
B)Renal failure
C)Trauma to the hypothalamus
D)Pancreatitis

Accepted Answer

Renal failure usually causes hypermagnesemia, in which magnesium concentration is greater than 2.5 mEq/L. Hypermagnesemia is not a result of the other options.

Question 8

A patient's serum potassium level is 2.7 mEq/L. Which clinical manifestations does the healthcare professional assess for? (Select all that apply.)
A)Paralytic ileus
B)Sinus bradycardia
C)Atrioventricular block
D)Dry mucous membranes
E)Tetany

Accepted Answer

Normal potassium level is 3.5 to 5.0 mEq/L so this patient has hypokalemia. A variety of dysrhythmias may occur, including sinus bradycardia, atrioventricular block, paroxysmal atrial tachycardia, and paralytic ileus. The other options are not related to hypokalemia.

Question 9

Where is two thirds of the body's water found?
A)Interstitial fluid spaces
B)Vascular system
C)Intracellular fluid compartments
D)Intraocular fluids

Accepted Answer

Two thirds of the body's water is in the intracellular fluid (ICF) compartment, and one third is in the extracellular fluid (ECF) compartment. The two main ECF compartments are the interstitial fluid and the intravascular fluid, which is the blood plasma. Other ECF compartments include the lymph and the transcellular fluids, such as the synovial, intestinal, biliary, hepatic, pancreatic, and cerebrospinal fluids; sweat; urine; and pleural, synovial, peritoneal, pericardial, and intraocular fluids.

Question 10

A patient is admitted to the hospital with dehydration. For which signs or symptoms would the healthcare professional assess? (Select all that apply.)
A)Moist mucous membranes
B)Weak pulses
C)Tachycardia
D)Polyuria
E)Weight loss

Accepted Answer

Symptoms of dehydration include weak pulses, tachycardia, and weight loss among others. Moist mucus membranes are normal and indicate normal fluid balance. Polyuria would indicate either a disease state or fluid volume overload.

Question 11

A patient is admitted with hyponatremia. For which clinical manifestations would the healthcare professional assess? (Select all that apply.)
A)Headache
B)Seizures
C)Paranoia
D)Confusion
E)Lethargy

Accepted Answer

Behavioral and neurologic changes characteristic of hyponatremia include lethargy, headache, confusion, apprehension, seizures, and coma. Paranoia is not associated with hyponatremia.

Question 12

A healthcare professional is caring for four patients. Which patient should the professional assess for hyperkalemia?
A)Hyperparathyroidism
B)Vomiting
C)Renal failure
D)Hyperaldosteronism

Accepted Answer

Hyperkalemia should be investigated when a history of renal disease, massive trauma, insulin deficiency, Addison disease, use of potassium salt substitutes, or metabolic acidosis exists. Hyperparathyroidism might lead to hyperphosphatemia. Vomiting is frequently associated with potassium depletion. Hyperaldosteronism also can lead to potassium wasting.

Question 13

A patient has a history of excessive use of magnesium-containing antacids and aluminum-containing antacids. What lab value does the healthcare professional correlate to this behavior?
A)Magnesium 1.8 mg/dL
B)Phosphate 1.9 mg/dL
C)Sodium 149 mEq/L
D)Potassium 2.5 mEq/L

Accepted Answer

Excessive use of magnesium-containing and aluminum-containing antacids can lead to hypophosphatemia, which is a serum level less than 2 mg/dL. The magnesium level is normal, but magnesium is not related. The sodium level is high, but that is not related. The potassium level is low, but this is also not related.

Question 14

What are the causes of hypocalcemia? (Select all that apply.)
A)Repeated blood administration
B)Pancreatitis
C)Decreased reabsorption of calcium
D)Hyperparathyroidism
E)Kidney stones

Accepted Answer

Blood transfusions are a common cause of hypocalcemia because the citrate solution used in storing whole blood binds with calcium. Pancreatitis causes a release of lipases into soft-tissue spaces; consequently, the free fatty acids that are formed bind calcium, causing a decrease in ionized calcium. The other options are not recognized causes of hypocalcemia.

Question 15

A patient's chart indicates Kussmaul respirations. The student asks the healthcare professional what this is caused by. What response by the professional is most accurate?
A)Anxiety leads to Kussmaul respirations and is a cause of respiratory acidosis.
B)A compensatory measure is needed to correct metabolic acidosis.
C)Diabetic ketoacidosis is leading to metabolic acidosis.
D)More oxygen is necessary to compensate for respiratory acidosis.

Accepted Answer

Deep, rapid respirations (Kussmaul respirations) are indicative of respiratory compensation for metabolic acidosis. Anxiety would lead to respiratory alkalosis as carbon dioxide is blown off by the lungs. Kussmaul's respirations may be seen in diabetic ketoacidosis, but they do not diagnose it. Kussmaul's respirations are not present in respiratory acidosis.

Question 16

A healthcare professional just administered a large dose of insulin to a patient. Which electrolyte value should the professional monitor as a priority?
A)Sodium
B)Potassium
C)Calcium
D)Magnesium

Accepted Answer

Insulin contributes to the regulation of plasma potassium levels by stimulating the Na⁺, K⁺-ATPase pump, thereby promoting the movement of potassium into the cells. The professional should monitor this patient's potassium level as a priority. The other electrolytes are not directly influenced by insulin administration.

Question 17

A patient's electrocardiogram (ECG) shows tall, peaked T waves. What lab value or assessment would the healthcare professional correlate with this finding?
A)Positive Chvostek sign
B)Serum potassium 6.7 mEq/L
C)Nausea and vomiting
D)Serum sodium 138 mEq/L

Accepted Answer

Tall peaked T waves on an ECG are indicative of hyperkalemia. Normal potassium is 3.5 to 5.0 mEq/L. A positive Chvostek sign is indicative of hypocalcemia. Nausea and vomiting are not related.

Question 18

A patient has been diagnosed with hypercalcemia. Which manifestations does the healthcare professional assess for? (Select all that apply.)
A)Diarrhea
B)Calcium-based kidney stones
C)ECG showing narrow T waves
D)Lethargy
E)Bradycardia

Accepted Answer

Fatigue, weakness, lethargy, anorexia, nausea, and constipation are common. Behavioral changes may occur. Impaired renal function frequently develops, and kidney stones form as precipitates of calcium salts. A shortened QT segment and depressed widened T waves also may be observed on the ECG, with bradycardia and varying degrees of heart block.

Question 19

Why does increased capillary hydrostatic pressure result in edema?
A)Losses or diminished production of plasma albumin
B)Inflammation resulting from an immune response
C)Blockage within the lymphatic channel system
D)Sodium and water retention

Accepted Answer

Increased capillary hydrostatic pressure can result from venous obstruction or sodium and water retention. The other options do not accurately describe the cause of edema related to increased capillary hydrostatic pressure.

Question 20

Which groups are at risk for fluid imbalance? (Select all that apply.)
A)Women
B)Infants
C)Men
D)Obese persons
E)Older adults

Accepted Answer

Kidney function, surface area, total body water, and the hydrophobic nature of fat cells all contribute to the increased risk for fluid imbalance among obese individuals, infants, and older adults. Gender alone is not a risk factor for fluid imbalance.

Quiz 3: The Cellular Environment: Fluids and Electrolytes, Acids and Bases

Which statements regarding total body water (TBW) are true? (Select all that apply.)

A third of the body's fluid is contained in the extracellular interstitial fluid spaces that include what? (Select all that apply.)

In hyperkalemia, what change occurs to the cells' resting membrane potential?

Physiologic pH is maintained at approximately 7.4 because bicarbonate (HCO₃) and carbonic acid (H₂CO₃) exist in what ratio?

An imbalance of potassium can produce which dysfunctions? (Select all that apply.)

A healthcare provider notes that tapping the patient's facial nerve leads to lip twitching. What electrolyte value is correlated with this finding?

A healthcare professional is caring for four patients. Which patient should the professional assess for hypermagnesemia as a priority?

A patient's serum potassium level is 2.7 mEq/L. Which clinical manifestations does the healthcare professional assess for? (Select all that apply.)

Where is two thirds of the body's water found?

A patient is admitted to the hospital with dehydration. For which signs or symptoms would the healthcare professional assess? (Select all that apply.)

A patient is admitted with hyponatremia. For which clinical manifestations would the healthcare professional assess? (Select all that apply.)

A healthcare professional is caring for four patients. Which patient should the professional assess for hyperkalemia?

A patient has a history of excessive use of magnesium-containing antacids and aluminum-containing antacids. What lab value does the healthcare professional correlate to this behavior?

What are the causes of hypocalcemia? (Select all that apply.)

A patient's chart indicates Kussmaul respirations. The student asks the healthcare professional what this is caused by. What response by the professional is most accurate?

A healthcare professional just administered a large dose of insulin to a patient. Which electrolyte value should the professional monitor as a priority?

A patient's electrocardiogram (ECG) shows tall, peaked T waves. What lab value or assessment would the healthcare professional correlate with this finding?

A patient has been diagnosed with hypercalcemia. Which manifestations does the healthcare professional assess for? (Select all that apply.)

Why does increased capillary hydrostatic pressure result in edema?

Which groups are at risk for fluid imbalance? (Select all that apply.)