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)?

Accepted Answer

D

Question 2

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

Accepted Answer

Hypokalemia can cause an increase in heart rate, leading to weakness, difficulty in breathing, and eventual cardiac arrest. This is because potassium plays a crucial role in regulating cardiac muscle contraction and the influx and efflux of ions across cardiac cell membranes. When potassium levels are low, the heart muscle loses its ability to maintain a steady and controlled rhythm, potentially leading to life-threatening arrhythmias.

Question 3

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

Accepted Answer

Healthy kidneys compensate for metabolic acidosis by increasing the excretion of acid, which helps to neutralize the excess hydrogen ions and raise the blood pH back towards normal levels.

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?

Accepted Answer

Edema and organ failure can cause a shift of fluid from the bloodstream to the interstitial spaces, leading to dilutional hyponatremia due to low levels of sodium in the blood.

Question 5

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

Accepted Answer

Lactate is not typically considered a primary buffer in maintaining body pH. The main physiological buffers include bicarbonate, phosphate, and proteins such as albumin, which help maintain the acid-base balance in the body. Lactate is a byproduct of anaerobic metabolism and can contribute to acidosis if it accumulates, but it is not used by the body as a buffer system.

Question 6

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

Accepted Answer

Peripheral chemoreceptors are primarily stimulated by changes in arterial blood pH and PO₂ content, with the latter being a more potent stimulator. HCO₃ content, while affecting respiration, is not a primary stimulus for peripheral chemoreceptors.

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?

Accepted Answer

The patient has decreased serum sodium and low serum osmolality indicating hyponatremia. The increased urine sodium suggests that the patient is losing salt in the urine. This is consistent with depletional hyponatremia, which is caused by a loss of sodium in the body, typically due to renal tubular disorders such as salt-losing nephropathy.

Question 8

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

Accepted Answer

In a state of metabolic acidosis, healthy lungs can compensate by stimulating hyperventilation. This results in increased excretion of carbon dioxide, which helps to raise blood pH by decreasing the concentration of carbonic acid in the blood. This compensatory mechanism is known as respiratory compensation. Options A, C, and D are all methods that the kidneys can use to compensate for acidosis, but they are not relevant to how the lungs compensate for acidosis.

Question 9

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

Accepted Answer

Hyponatremia with decreased plasma osmolality and normal volume status can be caused by excessive water intake, SIADH (syndrome of inappropriate antidiuretic hormone secretion), or impaired renal water excretion due to medication side effects or kidney dysfunction. However, diarrhea, as it leads to dehydration and decreased extracellular fluid volume, is not a cause of hyponatremia with decreased plasma osmolality and normal volume status.

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?

Accepted Answer

The arterial blood gas results indicate metabolic acidosis with respiratory compensation (elevated PCO2). The high anion gap and marked urine glucose and ketones suggest diabetic ketoacidosis as the most likely cause of the acid-base disorder. The patient's blurred vision and thirst can also be attributed to hyperglycemia, which is a hallmark symptom of DKA. Abscess formation and infection may cause an inflammatory response but do not typically cause metabolic acidosis. Pneumonia may cause respiratory acidosis, but the blood gas results do not support this diagnosis. Hysteria is not a medical condition and is not a likely cause of the patient's symptoms.

Question 11

Hypokalemia may be seen in all of the following except:

Accepted Answer

Decreased glucocorticoid concentration in blood does not directly cause hypokalemia. Hypokalemia can be caused by decreased dietary intake, renal loss, and gastrointestinal loss.

Question 12

Hypernatremia commonly occurs with:

Accepted Answer

Hypernatremia occurs when there is an excess of sodium in the body relative to the amount of water. This can occur with decreased synthesis of antidiuretic hormone (ADH) which regulates water balance in the body. Without enough ADH, the kidneys do not retain enough water, leading to hypernatremia.

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?

Accepted Answer

The patient is in a state of metabolic acidosis, as evidenced by the low arterial pH (7.2), low bicarbonate levels (8 mmol/L), and high anion gap. The elevated blood glucose and urine glucose and ketones suggest that the patient is experiencing diabetic ketoacidosis, which is a common cause of metabolic acidosis. The patient's symptoms of thirst, blurred vision, rapid breathing, and irritability are also typical of diabetic ketoacidosis. There is no evidence of respiratory acidosis or alkalosis based on the given information. There is also no evidence of metabolic alkalosis as the bicarbonate levels are low.

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?

Accepted Answer

Narcotic overdose and respiratory depression can lead to hypoventilation, leading to an increase in carbon dioxide levels and a decrease in oxygen levels, resulting in respiratory acidosis.

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:

Accepted Answer

Inorganic acidosis with a normal anion gap is typically caused by the loss of bicarbonate-rich fluid via the kidneys or gastrointestinal tract. Examples include diarrhea, pancreatic or biliary fistulas, and renal tubular acidosis. Uncontrolled diabetes mellitus and an acquired defect in enzymes involved in gluconeogenesis can cause metabolic organic acidoses with an increased anion gap. Production of glycolic and oxalic acids is not a common cause of acidosis.

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?

Accepted Answer

To calculate the anion gap, we use the formula: 
Anion gap = (Na + K) - (Cl + HCO3)

Plugging in the values, 
Anion gap = (132+4) - (90+22) 
Anion gap = 24

The healthy reference interval for the anion gap is generally between 8-16 mmol/L. Since our calculated anion gap is 24, it is above the healthy reference interval, indicating a possible underlying medical condition. Therefore, the correct answer is B (No).

Question 17

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

Accepted Answer

Salicylate intoxication can cause an increased anion gap due to the accumulation of organic acids.

Answer: C 
 Decreased albumin concentration can also cause an increased anion gap as albumin is a negatively charged protein that contributes to the normal anion gap.

Question 18

The most important buffer of plasma is the _____ system.

Accepted Answer

The bicarbonate/carbonic acid system is the most important buffer of plasma, as it helps maintain a stable pH by regulating the amount of bicarbonate and carbonic acid in the blood. Other buffers, such as proteins and phosphates, also play a role, but the bicarbonate/carbonic acid system is the primary one. Hemoglobin erythrocyte is not a buffer system.

Question 19

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

Accepted Answer

Chloride responsive metabolic alkalosis occurs when there is an excess loss of acid (or gain of base) via the gastrointestinal tract or kidneys, leading to a primary bicarbonate excess. This is often seen in cases of prolonged vomiting, where there is loss of hydrochloric acid in the gastric contents. A primary bicarbonate deficit would result in metabolic acidosis, which is not consistent with this scenario. A deficit or excess of cdCO₂ (I am unsure what this refers to) is not relevant to the case.

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?

Accepted Answer

The anion gap formula is [(Na+K) - (Cl + HCO3)]. Using the values given, we have:

[(132+4) - (90+22)] = 24

Therefore, the anion gap is 24 mmol/L, which corresponds to Choice C (20 mmol/L). The other choices (A, B, and D) are not correct as they do not match the calculated anion gap.

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

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) ?

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

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

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?

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

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

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

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

Hypokalemia may be seen in all of the following except:

Hypernatremia commonly occurs with:

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?

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:

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?

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

The most important buffer of plasma is the _____ system.

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

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?

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

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) ?

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

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

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?

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

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

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

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

Hypokalemia may be seen in all of the following except:

Hypernatremia commonly occurs with:

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?

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:

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?

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

The most important buffer of plasma is the _____ system.

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

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?

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) ?

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?

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?