A 21-year-old man with insulin-dependent (type 1)diabetes mellitus who forgot to inject his insulin is seen in the emergency department.The following laboratory data are obtained: Serum [Na+] = 140 mEq/L (normal: 135 to 147 mEq/L) Serum [K+] = 6.5 mEq/L (normal: 3.5 to 5.0 mEq/L) Serum [HCO3-] = 10 mEq/L (normal: 22 to 28 mEq/L) Blood pH = 7.0 (normal: 7.35 to 7.45) Arterial partial pressure of carbon dioxide (Pco2)= 25 mm Hg (normal: 33 to 44 mm Hg) Serum glucose concentration = 1000 mg/dL (normal: 70 to 110 mg/dL) Which of the following plays the most important role in the generation of hyperkalemia in this man?

A) Low plasma osmolality B) Low arterial Pco2 C) Hyponatremia D) Metabolic acidosis E) Low plasma insulin concentration A) Low plasma osmolality B) Low arterial Pco2 C) Hyponatremia D) Metabolic acidosis E) Low plasma insulin concentration E

Exam 36: Potassium, calcium, and Phosphate Homeostasis

A healthy individual,weighing 60 kg,receives an infusion of 1 L of isotonic saline to which 20 mEq of K⁺ has been added.After the infusion,the plasma [K⁺] of this individual has increased from 3.5 mEq/L to 7.8 mEq/L.What is the most plausible explanation for the development of hyperkalemia in this individual?

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(Multiple Choice)

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Question 1

Correct Answer:

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Urinary K⁺ excretion is increased by which of the following?

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Question 2

Correct Answer:

Verified

A 21-year-old man with insulin-dependent (type 1)diabetes mellitus who forgot to inject his insulin is seen in the emergency department.The following laboratory data are obtained: Serum [Na⁺] = 140 mEq/L (normal: 135 to 147 mEq/L) Serum [K⁺] = 6.5 mEq/L (normal: 3.5 to 5.0 mEq/L) Serum [HCO₃^-] = 10 mEq/L (normal: 22 to 28 mEq/L) Blood pH = 7.0 (normal: 7.35 to 7.45) Arterial partial pressure of carbon dioxide (Pco₂)= 25 mm Hg (normal: 33 to 44 mm Hg) Serum glucose concentration = 1000 mg/dL (normal: 70 to 110 mg/dL) Which of the following plays the most important role in the generation of hyperkalemia in this man?

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(Multiple Choice)

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Question 3

Correct Answer:

Verified

Which of the following enhances urinary K⁺ excretion?

(Multiple Choice)

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Question 4

A 45-year-old man is prescribed an angiotensin-converting enzyme inhibitor as part of his therapy for hypertension.If he does not change his diet,what changes in his serum [Na⁺] and serum [K⁺] would you expect?

(Short Answer)

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Question 5

Which of the following conditions would be expected to reduce the free (i.e.,ionized)[Ca⁺⁺] in the plasma?

(Multiple Choice)

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Question 6

Hyperkalemia is most likely to occur in which of the following conditions?

(Multiple Choice)

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Question 7

Which of the following hormones plays an important role in keeping the plasma concentration of K⁺ within normal limits?

(Multiple Choice)

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Question 8

A 65-year-old man has chronic renal failure.What are the expected changes in his serum Ca⁺⁺,inorganic phosphate (P_i),and calcitriol levels? (Note: Changes are those expected in comparison with the values in an individual with normal renal function.)

(Short Answer)

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Question 9

Showing 1 - 9 of 9

Exam 36: Potassium, calcium, and Phosphate Homeostasis

Urinary K+ excretion is increased by which of the following?

Which of the following enhances urinary K+ excretion?

A 45-year-old man is prescribed an angiotensin-converting enzyme inhibitor as part of his therapy for hypertension.If he does not change his diet,what changes in his serum [Na+] and serum [K+] would you expect?

Which of the following conditions would be expected to reduce the free (i.e.,ionized)[Ca++] in the plasma?

Hyperkalemia is most likely to occur in which of the following conditions?

Which of the following hormones plays an important role in keeping the plasma concentration of K+ within normal limits?

A 65-year-old man has chronic renal failure.What are the expected changes in his serum Ca++,inorganic phosphate (Pi),and calcitriol levels? (Note: Changes are those expected in comparison with the values in an individual with normal renal function.)

Principles of Cell Function

Homeostasis of Body Fluids

Signal Transduction, membrane Receptors, second Messengers, and Regulation of Gene Expression

The Nervous System: Introduction to Cells and Systems

Generation and Conduction of Action Potentials

Synaptic Transmission

The Somatosensory System

The Special Senses

Organization of Motor Function

Higher Functions of the Nervous System

The Autonomic Nervous System and Its Central Control

Skeletal Muscle Physiology

Cardiac Muscle

Smooth Muscle

Overview of Circulation

Elements of Cardiac Function

Properties of the Vasculature

Regulation of the Heart and Vasculature

Integrated Control of the Cardiovascular System

Structure and Function of the Respiratory System

Static Lung and Chest Wall Mechanics

Dynamic Lung and Chest Wall Mechanics

Ventilation

Oxygen and Carbon Dioxide Transport

Control of Respiration

Non-Physiologic Functions of the Lung: Host Defense and Metabolism

Functional Anatomy and General Principles of Regulation in the Gastrointestinal Tract

The Cephalic, oral, and Esophageal Phases of the Integrated Response to a Meal

The Gastric Phase of the Integrated Response to a Meal

The Small Intestinal Phase of the Integrated Response to a Meal

The Colonic Phase of the Integrated Response to a Meal

Transport and Metabolic Functions of the Liver

Elements of Renal Function

Solute and Water Transport Along the Nephron: Tubular Function

Control of Body Fluid Osmolality and Volume

Role of the Kidneys in the Regulation of Acid-Base Balance

Introduction to the Endocrine System

Hormonal Regulation of Energy Metabolism

Hormonal Regulation of Calcium and Phosphate Metabolism

The Hypothalamus and Pituitary Gland

The Thyroid Gland

The Adrenal Glands

The Male and Female Reproductive Systems

Filters

Urinary K⁺ excretion is increased by which of the following?

Which of the following enhances urinary K⁺ excretion?

A 45-year-old man is prescribed an angiotensin-converting enzyme inhibitor as part of his therapy for hypertension.If he does not change his diet,what changes in his serum [Na⁺] and serum [K⁺] would you expect?

Which of the following conditions would be expected to reduce the free (i.e.,ionized)[Ca⁺⁺] in the plasma?

Which of the following hormones plays an important role in keeping the plasma concentration of K⁺ within normal limits?

A 65-year-old man has chronic renal failure.What are the expected changes in his serum Ca⁺⁺,inorganic phosphate (P_i),and calcitriol levels? (Note: Changes are those expected in comparison with the values in an individual with normal renal function.)