Deck 36: Physiology and Disorders of Water,Electrolyte,and Acid-Base Metabolism

Question 1

At physiological pH of 7.4,which one of the following contributes most to the total serum CO₂ (think about the equilibrium of the reaction in the formula)?

A) Dissolved CO₂
B) Carbaminohemoglobin
C) HCO₃^-
D) Carbonic acid

Answer 1

Carbonic acid

Question 2

Hypokalemia (<3.0 mmol/L)is considered a serious health threat because:

A) the heart rate increases,leading to weakness,difficulty in breathing,and eventual cardiac arrest.
B) the heart rate slows because of the lowered excitability of cardiac smooth muscle,leading to possible cardiac standstill.
C) the body gains water through the kidney reabsorption,leading to severe edema.
D) arterial pH will decrease (increased H⁺ concentration),leading to metabolic acidosis.

Answer 2

the heart rate increases,leading to weakness,difficulty in breathing,and eventual cardiac arrest.

Question 3

How do healthy kidneys compensate for the excess hydrogen ions and concurrent low pH observed in metabolic acidosis?

A) Releasing bicarbonate into urine
B) Stimulating hyperventilation
C) Decreasing urinary excretion of ammonia
D) Increasing excretion of acid

Answer 3

Increasing excretion of acid

Question 4

A hospitalized patient in the ICU has cirrhosis.After a period of time,the heart and kidneys begin to fail and the patient develops edema.What type of electrolyte disorder would develop from this situation?

A) Dilutional hyponatremia
B) Depletional hyponatremia
C) Hypernatremia
D) There would be no electrolyte disorder.

Question 5

Physiologically important buffers maintaining body pH include all of the following except:

A) bicarbonate.
B) albumin.
C) phosphate.
D) lactate.

Question 6

In regard to respiration,peripheral chemoreceptors located in the carotid arteries and aorta are stimulated by:

A) HCO₃ content of arterial blood.
B) PO₂ content of blood only.
C) pH only.
D) pH and PO₂ content of blood.

Question 7

An individual visits a physician with the complaint of nausea,mental confusion,and needing an excessive amount of salt all the time.Laboratory results indicate decreased serum sodium and low serum osmolality.Physical examination reveals hypovolemia with low orthostatic blood pressure and tachycardia.A urine sodium analysis was suggested by a laboratorian and urine sodium was found to be increased; the physician diagnoses a salt-losing nephropathy (a renal tubule disease).What type of electrolyte disorder is this?

A) Dilutional hyponatremia
B) Depletional hyponatremia
C) Hypernatremia
D) Metabolic acidosis

Question 8

How do healthy lungs compensate for the decrease in pH in a state of metabolic acidosis?

A) Releasing bicarbonate into urine
B) Stimulating hyperventilation
C) Decreasing urinary excretion of acid
D) Increasing excretion of acid

Question 9

All of the following are causes of hyponatremia with concomitant decreased plasma osmolality and normal volume status except:

A) decreased serum aldosterone.
B) hypothyroidism.
C) diarrhea.
D) decreased serum antidiuretic hormone (ADH).

Question 10

An overweight 55-year-old single woman from a rural farming area was brought to the emergency department by her neighbor.The woman had a large abscess on the bottom of her foot; she was irritable and complained of blurred vision and of being thirsty.Her breathing was rapid.The neighbor said that the only medication the woman was using was for blood pressure and sometimes an aspirin.Blood and urine samples were collected.Arterial blood gas results were: pH 7.2; PCO₂ 47 mm Hg; HCO₃ 8 mmol/L.Blood glucose was 340 mg/dL and a high anion gap was calculated.Urine glucose and ketones were markedly increased.Based on the laboratory values and symptoms of the woman,what is the most likely cause of her acid-base disorder?

A) Abscess formation and infection
B) Diabetic ketoacidosis
C) Pneumonia
D) Hysteria

Question 11

Hypokalemia may be seen in all of the following except:

A) decreased dietary intake.
B) renal loss.
C) gastrointestinal loss.
D) decreased glucocorticoid concentration in blood.

Question 12

Hypernatremia commonly occurs with:

A) decreased synthesis of antidiuretic hormone (ADH).
B) decreased aldosterone.
C) edema.
D) hyperkalemia.

Question 13

An overweight 55-year-old single woman from a rural farming area was brought to the emergency department by her neighbor.The woman had a large abscess on the bottom of her foot; she was irritable and complained of blurred vision and of being thirsty.Her breathing was rapid.The neighbor said that the only medication the woman was using was for blood pressure and sometimes an aspirin.Blood and urine samples were collected.Arterial blood gas results were: pH 7.2; PCO₂ 47 mm Hg; HCO₃ 8 mmol/L.Blood glucose was 340 mg/dL and a high anion gap was calculated.Urine glucose and ketones were markedly increased.Based on the laboratory values,what state of acid-base balance is this patient in?

A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis

Question 14

An individual is brought to the emergency department of a local hospital with signs of narcotic overdose and respiratory depression.What acid-base status would this individual have?

A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis

Question 15

Metabolic organic acidoses typically present with an increased anion gap.In contrast to these,inorganic acidosis with a normal anion gap is typically caused by:

A) uncontrolled diabetes mellitus.
B) loss of bicarbonate-rich fluid via the kidneys or gastrointestinal tract.
C) an acquired defect in enzymes involved in gluconeogenesis.
D) production of glycolic and oxalic acids.

Question 16

Determine the anion gap given the following serum electrolyte data: Na = 132 mmol/L,Cl^- = 90 mmol/L,HCO₃^- = 22 mmol/L,K = 4 mmol/L.Is the anion gap you calculated within the healthy reference interval?

A) Yes
B) No

Question 17

Which of the following conditions will cause an increased anion gap?

A) Salicylate intoxication
B) Controlled diabetes mellitus
C) Decreased albumin concentration
D) Severe diarrhea

Question 18

The most important buffer of plasma is the _____ system.

A) bicarbonate/carbonic acid
B) protein/albumin
C) phosphoric acid/phosphate
D) hemoglobin erythrocyte

Question 19

A person suspected of having chloride responsive metabolic alkalosis caused by prolonged vomiting would exhibit which one of the following?

A) Primary bicarbonate deficit
B) Primary bicarbonate excess
C) Primary cdCO₂ deficit
D) Primary cdCO₂ excess

Question 20

What is the anion gap given the following serum electrolyte data: Na = 132 mmol/L,Cl^- = 90 mmol/L,HCO₃^- = 22 mmol/L,K = 4 mmol/L?

A) 10 mmol/L
B) 18 mmol/L
C) 20 mmol/L
D) 60 mmol/L

Question 21

Which one of the following hormones is an active regulator of water retention/reabsorption in the kidney?

A) Aldosterone
B) Erythropoietin
C) Antidiuretic hormone
D) Renin

Question 22

MATCHING
Match the action of acid-base balance regulation with the correct component of acid-base balance.
Can alter blood pH

A)Metabolic component
B)Respiratory component
C)Both components

Question 23

Which one of the following hormones is an active regulator of sodium (and passive controller of water)in the kidney?

A) Aldosterone
B) Erythropoietin
C) Antidiuretic hormone
D) Renin

Question 24

MATCHING
Match the action of acid-base balance regulation with the correct component of acid-base balance.
Hydrogen ions are exchanged for sodium or potassium

A)Metabolic component
B)Respiratory component
C)Both components

Question 25

MATCHING
Match the action of acid-base balance regulation with the correct component of acid-base balance.
Hydrogen ions are attached to hemoglobin

A)Metabolic component
B)Respiratory component
C)Both components

Question 26

A 17-year-old woman was brought by her friends to the emergency room in an agitated state.She stated that she had broken up with her boyfriend and he had threatened her.Her temperature was 101° F,and she was breathing rapidly.She claimed that she could not slow her breathing down despite attempts to have her breathe deeply.An arterial blood gas revealed a pH of 7.54,HCO₃ of 18 mmol/L,and PCO₂ of 28 mm Hg.What is occurring in this patient?

A) Excess retention of acid via the renal route
B) Excess elimination of acid via the renal route
C) Excess elimination of acid via the respiratory route
D) Excess retention of bicarbonate via the respiratory route

Question 27

The metabolic component of acid-base regulation is the renal system.Which one of the following statements concerning this component is incorrect?

A) Renal tubule cells reabsorb sodium and bicarbonate to affect bicarbonate concentration.
B) Sodium and bicarbonate are important in the exchange of excess H⁺ ions,thus altering blood pH.
C) The renal system acts to remove excess H⁺ ions by combining them with HPO₄.
D) In the metabolic component,the renal system responds immediately to a change in acid-base status.