ANP 650 Midterm Exam | ANP-650 Advanced
Practice Nursing Midterm Study Guide & Exam Prep
2026/2027 | Comprehensive Adult Health
Assessment & Disease Management Review,
Cardiovascular, Respiratory, Neurological,
Endocrine, Ophthalmic, ENT, Musculoskeletal &
Multisystem Disorders, Clinical Reasoning,
Diagnostic Evaluation, Pharmacology, Practice
Questions, Answers & Detailed Rationales
Question 1: Which of the following best describes the primary mechanism by
which the kidney maintains a constant glomerular filtration rate despite
fluctuations in systemic blood pressure?
A. Tubuloglomerular feedback via the macula densa
B. Sympathetic nervous system-induced afferent arteriolar constriction
C. Myogenic autoregulation of the afferent arteriole
D. Renin-angiotensin-aldosterone system activation
CORRECT ANSWER: C. Myogenic autoregulation of the afferent arteriole
Rationale: The myogenic mechanism is the primary intrinsic response where stretch-
sensitive ion channels in the afferent arteriole trigger vasoconstriction in response to
increased pressure and vasodilation in response to decreased pressure. This ensures a
constant GFR. While tubuloglomerular feedback (A) also contributes, it is a secondary,
slower mechanism. Sympathetic stimulation (B) typically reduces GFR, and RAAS (D) is
a long-term systemic regulator.
Question 2: In a patient with metabolic acidosis, which renal compensatory
mechanism is expected to be most active?
A. Increased reabsorption of filtered bicarbonate in the proximal tubule
B. Excretion of ammonium (NH4+) and titratable acids
C. Secretion of hydrogen ions into the distal tubule and collecting duct
D. Increased production of carbonic anhydrase in the luminal membrane
CORRECT ANSWER: B. Excretion of ammonium (NH4+) and titratable acids
Rationale: The kidneys compensate for metabolic acidosis primarily by increasing the
excretion of acid in the form of ammonium (NH4+) and titratable acids (phosphate).
While H+ secretion (C) and bicarbonate reabsorption (A) are important, the ultimate net
acid excretion is best measured by the sum of NH4+ and titratable acids.
Question 3: An increase in the hydrostatic pressure of the Bowman's space
(capsular hydrostatic pressure) would have which direct effect on net filtration
pressure?
A. It would increase the net filtration pressure
B. It would decrease the net filtration pressure
,C. It would have no effect on the net filtration pressure
D. It would cause a reflexive increase in GFR
CORRECT ANSWER: B. It would decrease the net filtration pressure
Rationale: Net filtration pressure (NFP) is calculated as (Glomerular hydrostatic
pressure) - (Bowman's space hydrostatic pressure + Glomerular oncotic pressure). An
increase in Bowman's space hydrostatic pressure directly opposes filtration, thereby
decreasing NFP and GFR.
Question 4: Which of the following is the primary determinant of the
medullary osmotic gradient responsible for urine concentration?
A. The countercurrent multiplier system in the loop of Henle
B. The countercurrent exchanger system in the vasa recta
C. The permeability of the collecting duct to water
D. Urea recycling in the collecting duct
CORRECT ANSWER: A. The countercurrent multiplier system in the loop of
Henle
Rationale: The active transport of NaCl out of the thick ascending limb of the loop of
Henle, which is impermeable to water, creates the cortico-medullary osmotic gradient.
This is the "multiplier" function. The vasa recta (B) maintains the gradient without
dissipating it, ADH controls water permeability (C), and urea recycling (D) contributes to
the gradient in the inner medulla but is secondary.
Question 5: A patient presents with polyuria and polydipsia. Serum osmolality
is 310 mOsm/kg and urine osmolality is 150 mOsm/kg. What is the most
likely diagnosis?
A. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
B. Diabetes insipidus
C. Primary polydipsia
D. Diabetes mellitus
CORRECT ANSWER: B. Diabetes insipidus
Rationale: This patient has high serum osmolality (hyperosmolality) and low urine
osmolality (dilute urine), indicating the kidneys are unable to concentrate urine despite a
strong osmotic stimulus. This is classic diabetes insipidus (central or nephrogenic).
SIADH would present with low serum osmolality, primary polydipsia with low serum
osmolality, and diabetes mellitus with glucosuria.
Question 6: The glomerular filtration barrier is composed of three layers.
Which layer is primarily responsible for the charge selectivity of the barrier?
A. Fenestrated capillary endothelium
B. Basement membrane
,C. Slit diaphragm between podocyte foot processes
D. Mesangial cells
CORRECT ANSWER: B. Basement membrane
Rationale: The glomerular basement membrane (GBM) is rich in negatively charged
proteoglycans (e.g., heparan sulfate). This negative charge repels negatively charged
plasma proteins like albumin, providing charge selectivity. The endothelium offers size
selectivity, and the slit diaphragm is the final size barrier.
Question 7: Which of the following describes the function of the efferent
arteriole in the kidney?
A. It carries blood from the renal artery into the glomerulus.
B. It is the primary site for the reabsorption of glucose.
C. It carries blood away from the glomerulus and creates post-glomerular resistance.
D. It transports urine from the renal pelvis to the ureter.
CORRECT ANSWER: C. It carries blood away from the glomerulus and creates
post-glomerular resistance.
Rationale: The efferent arteriole carries blood from the glomerulus to the peritubular
capillaries. Its constriction increases post-glomerular resistance, which helps maintain
glomerular hydrostatic pressure and thus GFR. It is a key regulator of renal blood flow.
Question 8: A 55-year-old male with a history of essential hypertension has a
serum creatinine of 2.5 mg/dL. Which of the following is the most accurate
interpretation of this finding?
A. His glomerular filtration rate is normal.
B. His glomerular filtration rate is significantly reduced.
C. He has an acute kidney injury.
D. He is overhydrated.
CORRECT ANSWER: B. His glomerular filtration rate is significantly reduced.
Rationale: Serum creatinine is a poor indicator of GFR in the normal range but is a
reliable indicator of reduced GFR. A creatinine of 2.5 mg/dL is well above the normal
range (0.6-1.2 mg/dL), indicating a significant loss of renal function (reduced GFR).
Without a baseline, it's impossible to distinguish acute from chronic (C).
Question 9: Which part of the nephron is completely impermeable to water in
the absence of ADH?
A. Proximal convoluted tubule
B. Descending loop of Henle
C. Thick ascending limb of the loop of Henle
D. Cortical collecting duct
CORRECT ANSWER: C. Thick ascending limb of the loop of Henle
, Rationale: The thick ascending limb is always impermeable to water, regardless of ADH
levels. This impermeability is crucial for its role in the countercurrent multiplier system.
The descending limb (B) is permeable to water, and the collecting duct (D) is permeable
only in the presence of ADH.
Question 10: What is the primary role of the renin-angiotensin-aldosterone
system (RAAS) during periods of hypotension?
A. To decrease systemic vascular resistance
B. To promote sodium and water retention
C. To decrease cardiac contractility
D. To stimulate the release of ADH
CORRECT ANSWER: B. To promote sodium and water retention
Rationale: The RAAS is activated in response to hypotension. Angiotensin II is a potent
vasoconstrictor, and aldosterone promotes sodium reabsorption in the distal nephron.
The net effect is an increase in blood volume and systemic vascular resistance, leading
to restoration of blood pressure.
Question 11: A patient's arterial blood gas (ABG) shows pH 7.32, PaCO2 55
mmHg, and HCO3- 26 mEq/L. This is consistent with which of the following
acid-base disorders?
A. Metabolic acidosis with respiratory compensation
B. Respiratory acidosis with no metabolic compensation
C. Metabolic alkalosis with respiratory compensation
D. Respiratory acidosis with full metabolic compensation
CORRECT ANSWER: B. Respiratory acidosis with no metabolic compensation
Rationale: The pH is low (acidemia). The PaCO2 is elevated (55 mmHg), indicating a
respiratory acidosis. The HCO3- is normal (26 mEq/L), indicating that the metabolic
compensation has not yet occurred (acute respiratory acidosis). In chronic respiratory
acidosis, HCO3- would be elevated.
Question 12: Hyperkalemia is a potential side effect of which class of
medications due to their action on the distal nephron?
A. Loop diuretics
B. Thiazide diuretics
C. Aldosterone antagonists (e.g., spironolactone)
D. ACE inhibitors
CORRECT ANSWER: C. Aldosterone antagonists (e.g., spironolactone)
Rationale: Aldosterone antagonists block the action of aldosterone in the principal cells
of the collecting duct. This reduces the activity of the sodium-potassium ATPase pump
and epithelial sodium channels, leading to decreased sodium reabsorption and
decreased potassium secretion, resulting in hyperkalemia.
Practice Nursing Midterm Study Guide & Exam Prep
2026/2027 | Comprehensive Adult Health
Assessment & Disease Management Review,
Cardiovascular, Respiratory, Neurological,
Endocrine, Ophthalmic, ENT, Musculoskeletal &
Multisystem Disorders, Clinical Reasoning,
Diagnostic Evaluation, Pharmacology, Practice
Questions, Answers & Detailed Rationales
Question 1: Which of the following best describes the primary mechanism by
which the kidney maintains a constant glomerular filtration rate despite
fluctuations in systemic blood pressure?
A. Tubuloglomerular feedback via the macula densa
B. Sympathetic nervous system-induced afferent arteriolar constriction
C. Myogenic autoregulation of the afferent arteriole
D. Renin-angiotensin-aldosterone system activation
CORRECT ANSWER: C. Myogenic autoregulation of the afferent arteriole
Rationale: The myogenic mechanism is the primary intrinsic response where stretch-
sensitive ion channels in the afferent arteriole trigger vasoconstriction in response to
increased pressure and vasodilation in response to decreased pressure. This ensures a
constant GFR. While tubuloglomerular feedback (A) also contributes, it is a secondary,
slower mechanism. Sympathetic stimulation (B) typically reduces GFR, and RAAS (D) is
a long-term systemic regulator.
Question 2: In a patient with metabolic acidosis, which renal compensatory
mechanism is expected to be most active?
A. Increased reabsorption of filtered bicarbonate in the proximal tubule
B. Excretion of ammonium (NH4+) and titratable acids
C. Secretion of hydrogen ions into the distal tubule and collecting duct
D. Increased production of carbonic anhydrase in the luminal membrane
CORRECT ANSWER: B. Excretion of ammonium (NH4+) and titratable acids
Rationale: The kidneys compensate for metabolic acidosis primarily by increasing the
excretion of acid in the form of ammonium (NH4+) and titratable acids (phosphate).
While H+ secretion (C) and bicarbonate reabsorption (A) are important, the ultimate net
acid excretion is best measured by the sum of NH4+ and titratable acids.
Question 3: An increase in the hydrostatic pressure of the Bowman's space
(capsular hydrostatic pressure) would have which direct effect on net filtration
pressure?
A. It would increase the net filtration pressure
B. It would decrease the net filtration pressure
,C. It would have no effect on the net filtration pressure
D. It would cause a reflexive increase in GFR
CORRECT ANSWER: B. It would decrease the net filtration pressure
Rationale: Net filtration pressure (NFP) is calculated as (Glomerular hydrostatic
pressure) - (Bowman's space hydrostatic pressure + Glomerular oncotic pressure). An
increase in Bowman's space hydrostatic pressure directly opposes filtration, thereby
decreasing NFP and GFR.
Question 4: Which of the following is the primary determinant of the
medullary osmotic gradient responsible for urine concentration?
A. The countercurrent multiplier system in the loop of Henle
B. The countercurrent exchanger system in the vasa recta
C. The permeability of the collecting duct to water
D. Urea recycling in the collecting duct
CORRECT ANSWER: A. The countercurrent multiplier system in the loop of
Henle
Rationale: The active transport of NaCl out of the thick ascending limb of the loop of
Henle, which is impermeable to water, creates the cortico-medullary osmotic gradient.
This is the "multiplier" function. The vasa recta (B) maintains the gradient without
dissipating it, ADH controls water permeability (C), and urea recycling (D) contributes to
the gradient in the inner medulla but is secondary.
Question 5: A patient presents with polyuria and polydipsia. Serum osmolality
is 310 mOsm/kg and urine osmolality is 150 mOsm/kg. What is the most
likely diagnosis?
A. Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
B. Diabetes insipidus
C. Primary polydipsia
D. Diabetes mellitus
CORRECT ANSWER: B. Diabetes insipidus
Rationale: This patient has high serum osmolality (hyperosmolality) and low urine
osmolality (dilute urine), indicating the kidneys are unable to concentrate urine despite a
strong osmotic stimulus. This is classic diabetes insipidus (central or nephrogenic).
SIADH would present with low serum osmolality, primary polydipsia with low serum
osmolality, and diabetes mellitus with glucosuria.
Question 6: The glomerular filtration barrier is composed of three layers.
Which layer is primarily responsible for the charge selectivity of the barrier?
A. Fenestrated capillary endothelium
B. Basement membrane
,C. Slit diaphragm between podocyte foot processes
D. Mesangial cells
CORRECT ANSWER: B. Basement membrane
Rationale: The glomerular basement membrane (GBM) is rich in negatively charged
proteoglycans (e.g., heparan sulfate). This negative charge repels negatively charged
plasma proteins like albumin, providing charge selectivity. The endothelium offers size
selectivity, and the slit diaphragm is the final size barrier.
Question 7: Which of the following describes the function of the efferent
arteriole in the kidney?
A. It carries blood from the renal artery into the glomerulus.
B. It is the primary site for the reabsorption of glucose.
C. It carries blood away from the glomerulus and creates post-glomerular resistance.
D. It transports urine from the renal pelvis to the ureter.
CORRECT ANSWER: C. It carries blood away from the glomerulus and creates
post-glomerular resistance.
Rationale: The efferent arteriole carries blood from the glomerulus to the peritubular
capillaries. Its constriction increases post-glomerular resistance, which helps maintain
glomerular hydrostatic pressure and thus GFR. It is a key regulator of renal blood flow.
Question 8: A 55-year-old male with a history of essential hypertension has a
serum creatinine of 2.5 mg/dL. Which of the following is the most accurate
interpretation of this finding?
A. His glomerular filtration rate is normal.
B. His glomerular filtration rate is significantly reduced.
C. He has an acute kidney injury.
D. He is overhydrated.
CORRECT ANSWER: B. His glomerular filtration rate is significantly reduced.
Rationale: Serum creatinine is a poor indicator of GFR in the normal range but is a
reliable indicator of reduced GFR. A creatinine of 2.5 mg/dL is well above the normal
range (0.6-1.2 mg/dL), indicating a significant loss of renal function (reduced GFR).
Without a baseline, it's impossible to distinguish acute from chronic (C).
Question 9: Which part of the nephron is completely impermeable to water in
the absence of ADH?
A. Proximal convoluted tubule
B. Descending loop of Henle
C. Thick ascending limb of the loop of Henle
D. Cortical collecting duct
CORRECT ANSWER: C. Thick ascending limb of the loop of Henle
, Rationale: The thick ascending limb is always impermeable to water, regardless of ADH
levels. This impermeability is crucial for its role in the countercurrent multiplier system.
The descending limb (B) is permeable to water, and the collecting duct (D) is permeable
only in the presence of ADH.
Question 10: What is the primary role of the renin-angiotensin-aldosterone
system (RAAS) during periods of hypotension?
A. To decrease systemic vascular resistance
B. To promote sodium and water retention
C. To decrease cardiac contractility
D. To stimulate the release of ADH
CORRECT ANSWER: B. To promote sodium and water retention
Rationale: The RAAS is activated in response to hypotension. Angiotensin II is a potent
vasoconstrictor, and aldosterone promotes sodium reabsorption in the distal nephron.
The net effect is an increase in blood volume and systemic vascular resistance, leading
to restoration of blood pressure.
Question 11: A patient's arterial blood gas (ABG) shows pH 7.32, PaCO2 55
mmHg, and HCO3- 26 mEq/L. This is consistent with which of the following
acid-base disorders?
A. Metabolic acidosis with respiratory compensation
B. Respiratory acidosis with no metabolic compensation
C. Metabolic alkalosis with respiratory compensation
D. Respiratory acidosis with full metabolic compensation
CORRECT ANSWER: B. Respiratory acidosis with no metabolic compensation
Rationale: The pH is low (acidemia). The PaCO2 is elevated (55 mmHg), indicating a
respiratory acidosis. The HCO3- is normal (26 mEq/L), indicating that the metabolic
compensation has not yet occurred (acute respiratory acidosis). In chronic respiratory
acidosis, HCO3- would be elevated.
Question 12: Hyperkalemia is a potential side effect of which class of
medications due to their action on the distal nephron?
A. Loop diuretics
B. Thiazide diuretics
C. Aldosterone antagonists (e.g., spironolactone)
D. ACE inhibitors
CORRECT ANSWER: C. Aldosterone antagonists (e.g., spironolactone)
Rationale: Aldosterone antagonists block the action of aldosterone in the principal cells
of the collecting duct. This reduces the activity of the sodium-potassium ATPase pump
and epithelial sodium channels, leading to decreased sodium reabsorption and
decreased potassium secretion, resulting in hyperkalemia.
