PATHOPHYSIOLOGY 1 — EXAM 4 consisting
questions with correct answers and
rationales updated 2026 new!! Graded
A+
SECTION 1: RENAL & URINARY DISORDERS (Q1–Q20)
1. Which of the following best describes the glomerular filtration rate (GFR)?
A. The amount of urine produced per minute
B. The volume of blood flowing through the kidneys per minute
C. The volume of plasma filtered by the glomeruli per unit of time
D. The rate of tubular reabsorption in the nephron
Rationale: GFR measures the volume of plasma filtered through the glomerular capillaries into
Bowman's capsule per unit time. Normal GFR is approximately 125 mL/min. It is the gold standard
for assessing kidney function.
2. A patient presents with periorbital edema, proteinuria >3.5 g/day, hypoalbuminemia, and
hyperlipidemia. Which condition is most likely?
A. Nephrotic syndrome
B. Nephritic syndrome
C. Acute kidney injury
D. Urinary tract infection
Rationale: Nephrotic syndrome is characterized by massive proteinuria (>3.5 g/day),
hypoalbuminemia, generalized edema (often periorbital), and hyperlipidemia. The glomerular
membrane becomes excessively permeable to plasma proteins.
3. Which type of acute kidney injury (AKI) is caused by decreased renal perfusion?
, A. Prerenal AKI
B. Intrarenal AKI
C. Postrenal AKI
D. Chronic kidney disease
Rationale: Prerenal AKI results from decreased blood flow to the kidneys (e.g., hypovolemia, heart
failure, shock). The kidney itself is not damaged initially, but prolonged hypoperfusion can lead to
intrinsic damage.
4. A kidney stone composed of calcium oxalate would most likely be seen on which diagnostic test?
A. Urinalysis only
B. Cystoscopy only
C. X-ray (KUB)
D. Urine culture
Rationale: Calcium oxalate stones are radiopaque and can be visualized on plain abdominal X-ray
(KUB). They are the most common type of kidney stones, accounting for approximately 70-80% of all
renal calculi.
5. Which finding is most characteristic of nephritic syndrome?
A. Massive proteinuria >3.5 g/day
B. Hyperlipidemia
C. Hematuria with red blood cell casts
D. Severe hypoalbuminemia
Rationale: Nephritic syndrome is characterized by hematuria (often with RBC casts), mild-to-
moderate proteinuria, hypertension, and oliguria. RBC casts indicate glomerular origin of bleeding
and are pathognomonic for glomerulonephritis.
,6. In chronic kidney disease (CKD), at what GFR stage does the patient typically require dialysis or
transplant?
A. Stage 2 (GFR 60-89 mL/min)
B. Stage 3 (GFR 30-59 mL/min)
C. Stage 4 (GFR 15-29 mL/min)
D. Stage 5 (GFR <15 mL/min)
Rationale: Stage 5 CKD (end-stage renal disease/ESRD) is defined by GFR <15 mL/min. At this stage,
the kidneys can no longer maintain homeostasis, and renal replacement therapy (dialysis or
transplant) is necessary for survival.
7. What is the most common cause of chronic kidney disease in the United States?
A. Glomerulonephritis
B. Polycystic kidney disease
C. Hypertension
D. Diabetes mellitus
Rationale: Diabetes mellitus (particularly type 2) is the leading cause of CKD and ESRD in the United
States. Diabetic nephropathy results from chronic hyperglycemia causing damage to the glomerular
capillaries.
8. Which electrolyte imbalance is most dangerous in a patient with acute kidney injury?
A. Hyponatremia
B. Hyperkalemia
C. Hypocalcemia
D. Hyperphosphatemia
Rationale: Hyperkalemia is the most immediately life-threatening electrolyte imbalance in AKI. The
kidneys are responsible for excreting approximately 90% of potassium. Elevated potassium levels
can cause fatal cardiac arrhythmias (ventricular fibrillation, asystole).
, 9. A patient with CKD develops bone pain and pathologic fractures. This is primarily due to:
A. Hypernatremia
B. Metabolic alkalosis
C. Renal osteodystrophy from secondary hyperparathyroidism
D. Excessive vitamin D production
Rationale: In CKD, the kidneys cannot convert vitamin D to its active form (calcitriol), leading to
decreased calcium absorption. Hyperphosphatemia further lowers calcium. This stimulates PTH
release (secondary hyperparathyroidism), causing bone resorption and renal osteodystrophy.
10. Which of the following is the most common causative organism for urinary tract infections?
A. Escherichia coli
B. Staphylococcus aureus
C. Pseudomonas aeruginosa
D. Klebsiella pneumoniae
Rationale: E. coli accounts for approximately 80-90% of uncomplicated UTIs. It is a gram-negative
bacterium that is part of normal intestinal flora and can ascend the urethra to cause infection.
11. Postrenal acute kidney injury is most commonly caused by:
A. Nephrotoxic drugs
B. Severe dehydration
C. Obstruction of urine outflow
D. Glomerulonephritis
Rationale: Postrenal AKI results from obstruction of urinary outflow anywhere from the renal pelvis
to the urethra. Common causes include kidney stones, BPH, tumors, and blood clots. The obstruction
causes back-pressure that impairs kidney function.
questions with correct answers and
rationales updated 2026 new!! Graded
A+
SECTION 1: RENAL & URINARY DISORDERS (Q1–Q20)
1. Which of the following best describes the glomerular filtration rate (GFR)?
A. The amount of urine produced per minute
B. The volume of blood flowing through the kidneys per minute
C. The volume of plasma filtered by the glomeruli per unit of time
D. The rate of tubular reabsorption in the nephron
Rationale: GFR measures the volume of plasma filtered through the glomerular capillaries into
Bowman's capsule per unit time. Normal GFR is approximately 125 mL/min. It is the gold standard
for assessing kidney function.
2. A patient presents with periorbital edema, proteinuria >3.5 g/day, hypoalbuminemia, and
hyperlipidemia. Which condition is most likely?
A. Nephrotic syndrome
B. Nephritic syndrome
C. Acute kidney injury
D. Urinary tract infection
Rationale: Nephrotic syndrome is characterized by massive proteinuria (>3.5 g/day),
hypoalbuminemia, generalized edema (often periorbital), and hyperlipidemia. The glomerular
membrane becomes excessively permeable to plasma proteins.
3. Which type of acute kidney injury (AKI) is caused by decreased renal perfusion?
, A. Prerenal AKI
B. Intrarenal AKI
C. Postrenal AKI
D. Chronic kidney disease
Rationale: Prerenal AKI results from decreased blood flow to the kidneys (e.g., hypovolemia, heart
failure, shock). The kidney itself is not damaged initially, but prolonged hypoperfusion can lead to
intrinsic damage.
4. A kidney stone composed of calcium oxalate would most likely be seen on which diagnostic test?
A. Urinalysis only
B. Cystoscopy only
C. X-ray (KUB)
D. Urine culture
Rationale: Calcium oxalate stones are radiopaque and can be visualized on plain abdominal X-ray
(KUB). They are the most common type of kidney stones, accounting for approximately 70-80% of all
renal calculi.
5. Which finding is most characteristic of nephritic syndrome?
A. Massive proteinuria >3.5 g/day
B. Hyperlipidemia
C. Hematuria with red blood cell casts
D. Severe hypoalbuminemia
Rationale: Nephritic syndrome is characterized by hematuria (often with RBC casts), mild-to-
moderate proteinuria, hypertension, and oliguria. RBC casts indicate glomerular origin of bleeding
and are pathognomonic for glomerulonephritis.
,6. In chronic kidney disease (CKD), at what GFR stage does the patient typically require dialysis or
transplant?
A. Stage 2 (GFR 60-89 mL/min)
B. Stage 3 (GFR 30-59 mL/min)
C. Stage 4 (GFR 15-29 mL/min)
D. Stage 5 (GFR <15 mL/min)
Rationale: Stage 5 CKD (end-stage renal disease/ESRD) is defined by GFR <15 mL/min. At this stage,
the kidneys can no longer maintain homeostasis, and renal replacement therapy (dialysis or
transplant) is necessary for survival.
7. What is the most common cause of chronic kidney disease in the United States?
A. Glomerulonephritis
B. Polycystic kidney disease
C. Hypertension
D. Diabetes mellitus
Rationale: Diabetes mellitus (particularly type 2) is the leading cause of CKD and ESRD in the United
States. Diabetic nephropathy results from chronic hyperglycemia causing damage to the glomerular
capillaries.
8. Which electrolyte imbalance is most dangerous in a patient with acute kidney injury?
A. Hyponatremia
B. Hyperkalemia
C. Hypocalcemia
D. Hyperphosphatemia
Rationale: Hyperkalemia is the most immediately life-threatening electrolyte imbalance in AKI. The
kidneys are responsible for excreting approximately 90% of potassium. Elevated potassium levels
can cause fatal cardiac arrhythmias (ventricular fibrillation, asystole).
, 9. A patient with CKD develops bone pain and pathologic fractures. This is primarily due to:
A. Hypernatremia
B. Metabolic alkalosis
C. Renal osteodystrophy from secondary hyperparathyroidism
D. Excessive vitamin D production
Rationale: In CKD, the kidneys cannot convert vitamin D to its active form (calcitriol), leading to
decreased calcium absorption. Hyperphosphatemia further lowers calcium. This stimulates PTH
release (secondary hyperparathyroidism), causing bone resorption and renal osteodystrophy.
10. Which of the following is the most common causative organism for urinary tract infections?
A. Escherichia coli
B. Staphylococcus aureus
C. Pseudomonas aeruginosa
D. Klebsiella pneumoniae
Rationale: E. coli accounts for approximately 80-90% of uncomplicated UTIs. It is a gram-negative
bacterium that is part of normal intestinal flora and can ascend the urethra to cause infection.
11. Postrenal acute kidney injury is most commonly caused by:
A. Nephrotoxic drugs
B. Severe dehydration
C. Obstruction of urine outflow
D. Glomerulonephritis
Rationale: Postrenal AKI results from obstruction of urinary outflow anywhere from the renal pelvis
to the urethra. Common causes include kidney stones, BPH, tumors, and blood clots. The obstruction
causes back-pressure that impairs kidney function.
