AAERT CDR (CERTIFIED DIALYSIS RN) COMPLETE EXAM QUESTIONS AND
100% VERIFIED ANSWERS LATEST UPDATED (2026)
1. What is the primary functional unit of the kidney? Answer: The nephron
is the primary functional unit of the kidney, responsible for filtering blood and
forming urine.
2. How many nephrons are typically in each kidney? Answer: Each kidney
contains approximately 1-1.5 million nephrons.
3. What are the main components of a nephron? Answer: The glomerulus,
Bowman's capsule, proximal convoluted tubule, loop of Henle, distal
convoluted tubule, and collecting duct.
4. What is the normal glomerular filtration rate (GFR) in healthy adults?
Answer: Normal GFR is approximately 90-120 mL/min/1.73 m².
5. Which artery supplies blood to the kidneys? Answer: The renal artery,
which branches directly from the abdominal aorta.
6. What percentage of cardiac output do the kidneys receive? Answer: The
kidneys receive approximately 20-25% of cardiac output.
7. What is the function of the glomerulus? Answer: The glomerulus filters
blood, allowing water and small molecules to pass while retaining blood cells
and large proteins.
8. What is Bowman's capsule? Answer: Bowman's capsule is a cup-like
structure that surrounds the glomerulus and collects the filtrate.
9. What occurs in the proximal convoluted tubule? Answer: Reabsorption of
approximately 65% of filtered sodium, water, glucose, amino acids, and other
nutrients occurs here.
10. What is the function of the loop of Henle? Answer: The loop of Henle
concentrates urine by establishing an osmotic gradient in the renal medulla
through countercurrent multiplication.
,11. What does the distal convoluted tubule regulate? Answer: It regulates
sodium, potassium, and calcium balance, and pH through selective reabsorption
and secretion.
12. What hormone is produced by the kidneys to stimulate red blood cell
production? Answer: Erythropoietin (EPO) is produced by the kidneys in
response to hypoxia.
13. What is the role of renin? Answer: Renin is an enzyme released by the
kidneys that initiates the renin-angiotensin-aldosterone system (RAAS) to
regulate blood pressure and fluid balance.
14. What does the kidney convert vitamin D into? Answer: The kidney
converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxyvitamin D
(calcitriol).
15. What are the three main functions of the kidneys? Answer: Filtration of
waste products, regulation of fluid and electrolyte balance, and endocrine
functions (EPO, renin, active vitamin D production).
16. What is the juxtaglomerular apparatus? Answer: A specialized structure
near the glomerulus that regulates blood pressure and GFR through renin
secretion and tubuloglomerular feedback.
17. What is the normal urine output per day? Answer: Normal urine output
is approximately 800-2000 mL per day (or about 0.5-1 mL/kg/hour).
18. What is oliguria? Answer: Oliguria is urine output less than 400 mL per
day or less than 0.5 mL/kg/hour.
19. What is anuria? Answer: Anuria is urine output less than 50-100 mL per
day.
20. What electrolyte is primarily regulated by the kidneys? Answer: The
kidneys primarily regulate sodium, potassium, calcium, phosphorus, and
magnesium balance.
21. How do the kidneys regulate acid-base balance? Answer: By reabsorbing
bicarbonate, secreting hydrogen ions, and producing ammonia to buffer acids.
22. What is the normal pH range of blood? Answer: Normal blood pH is
7.35-7.45.
23. What is azotemia? Answer: Azotemia is an elevated blood urea nitrogen
(BUN) level, indicating impaired kidney function.
, 24. What is uremia? Answer: Uremia is a toxic clinical syndrome resulting
from severe kidney failure with accumulation of waste products in the blood.
25. What is the difference between acute kidney injury (AKI) and chronic
kidney disease (CKD)? Answer: AKI is a sudden decline in kidney function
(hours to days) that may be reversible, while CKD is progressive, irreversible
kidney damage lasting more than 3 months.
26. What are the stages of chronic kidney disease? Answer: Stage 1 (GFR
≥90), Stage 2 (GFR 60-89), Stage 3a (GFR 45-59), Stage 3b (GFR 30-44),
Stage 4 (GFR 15-29), Stage 5 (GFR <15 or on dialysis).
27. At what GFR is dialysis typically initiated? Answer: Dialysis is typically
initiated when GFR is less than 15 mL/min (Stage 5 CKD) or when uremic
symptoms develop.
28. What is the most common cause of end-stage renal disease (ESRD) in
the United States? Answer: Diabetes mellitus is the leading cause of ESRD,
accounting for approximately 40-45% of cases.
29. What is the second most common cause of ESRD? Answer: Hypertension
is the second leading cause, accounting for approximately 25-30% of cases.
30. What is glomerulonephritis? Answer: Glomerulonephritis is inflammation
of the glomeruli, which can be acute or chronic and may result from immune-
mediated damage.
31. What is polycystic kidney disease (PKD)? Answer: PKD is a genetic
disorder characterized by the growth of numerous cysts in the kidneys, leading
to progressive kidney dysfunction.
32. What is nephrotic syndrome? Answer: A clinical syndrome characterized
by heavy proteinuria (>3.5 g/day), hypoalbuminemia, edema, and
hyperlipidemia.
33. What is nephritic syndrome? Answer: A syndrome characterized by
hematuria, hypertension, oliguria, and mild to moderate proteinuria, often due to
glomerular inflammation.
34. What is the renal threshold for glucose? Answer: The renal threshold for
glucose is approximately 180-200 mg/dL; above this level, glucose appears in
the urine (glycosuria).
35. What is the macula densa? Answer: Specialized cells in the distal tubule
that sense sodium chloride concentration and regulate renin release and GFR.
100% VERIFIED ANSWERS LATEST UPDATED (2026)
1. What is the primary functional unit of the kidney? Answer: The nephron
is the primary functional unit of the kidney, responsible for filtering blood and
forming urine.
2. How many nephrons are typically in each kidney? Answer: Each kidney
contains approximately 1-1.5 million nephrons.
3. What are the main components of a nephron? Answer: The glomerulus,
Bowman's capsule, proximal convoluted tubule, loop of Henle, distal
convoluted tubule, and collecting duct.
4. What is the normal glomerular filtration rate (GFR) in healthy adults?
Answer: Normal GFR is approximately 90-120 mL/min/1.73 m².
5. Which artery supplies blood to the kidneys? Answer: The renal artery,
which branches directly from the abdominal aorta.
6. What percentage of cardiac output do the kidneys receive? Answer: The
kidneys receive approximately 20-25% of cardiac output.
7. What is the function of the glomerulus? Answer: The glomerulus filters
blood, allowing water and small molecules to pass while retaining blood cells
and large proteins.
8. What is Bowman's capsule? Answer: Bowman's capsule is a cup-like
structure that surrounds the glomerulus and collects the filtrate.
9. What occurs in the proximal convoluted tubule? Answer: Reabsorption of
approximately 65% of filtered sodium, water, glucose, amino acids, and other
nutrients occurs here.
10. What is the function of the loop of Henle? Answer: The loop of Henle
concentrates urine by establishing an osmotic gradient in the renal medulla
through countercurrent multiplication.
,11. What does the distal convoluted tubule regulate? Answer: It regulates
sodium, potassium, and calcium balance, and pH through selective reabsorption
and secretion.
12. What hormone is produced by the kidneys to stimulate red blood cell
production? Answer: Erythropoietin (EPO) is produced by the kidneys in
response to hypoxia.
13. What is the role of renin? Answer: Renin is an enzyme released by the
kidneys that initiates the renin-angiotensin-aldosterone system (RAAS) to
regulate blood pressure and fluid balance.
14. What does the kidney convert vitamin D into? Answer: The kidney
converts 25-hydroxyvitamin D to its active form, 1,25-dihydroxyvitamin D
(calcitriol).
15. What are the three main functions of the kidneys? Answer: Filtration of
waste products, regulation of fluid and electrolyte balance, and endocrine
functions (EPO, renin, active vitamin D production).
16. What is the juxtaglomerular apparatus? Answer: A specialized structure
near the glomerulus that regulates blood pressure and GFR through renin
secretion and tubuloglomerular feedback.
17. What is the normal urine output per day? Answer: Normal urine output
is approximately 800-2000 mL per day (or about 0.5-1 mL/kg/hour).
18. What is oliguria? Answer: Oliguria is urine output less than 400 mL per
day or less than 0.5 mL/kg/hour.
19. What is anuria? Answer: Anuria is urine output less than 50-100 mL per
day.
20. What electrolyte is primarily regulated by the kidneys? Answer: The
kidneys primarily regulate sodium, potassium, calcium, phosphorus, and
magnesium balance.
21. How do the kidneys regulate acid-base balance? Answer: By reabsorbing
bicarbonate, secreting hydrogen ions, and producing ammonia to buffer acids.
22. What is the normal pH range of blood? Answer: Normal blood pH is
7.35-7.45.
23. What is azotemia? Answer: Azotemia is an elevated blood urea nitrogen
(BUN) level, indicating impaired kidney function.
, 24. What is uremia? Answer: Uremia is a toxic clinical syndrome resulting
from severe kidney failure with accumulation of waste products in the blood.
25. What is the difference between acute kidney injury (AKI) and chronic
kidney disease (CKD)? Answer: AKI is a sudden decline in kidney function
(hours to days) that may be reversible, while CKD is progressive, irreversible
kidney damage lasting more than 3 months.
26. What are the stages of chronic kidney disease? Answer: Stage 1 (GFR
≥90), Stage 2 (GFR 60-89), Stage 3a (GFR 45-59), Stage 3b (GFR 30-44),
Stage 4 (GFR 15-29), Stage 5 (GFR <15 or on dialysis).
27. At what GFR is dialysis typically initiated? Answer: Dialysis is typically
initiated when GFR is less than 15 mL/min (Stage 5 CKD) or when uremic
symptoms develop.
28. What is the most common cause of end-stage renal disease (ESRD) in
the United States? Answer: Diabetes mellitus is the leading cause of ESRD,
accounting for approximately 40-45% of cases.
29. What is the second most common cause of ESRD? Answer: Hypertension
is the second leading cause, accounting for approximately 25-30% of cases.
30. What is glomerulonephritis? Answer: Glomerulonephritis is inflammation
of the glomeruli, which can be acute or chronic and may result from immune-
mediated damage.
31. What is polycystic kidney disease (PKD)? Answer: PKD is a genetic
disorder characterized by the growth of numerous cysts in the kidneys, leading
to progressive kidney dysfunction.
32. What is nephrotic syndrome? Answer: A clinical syndrome characterized
by heavy proteinuria (>3.5 g/day), hypoalbuminemia, edema, and
hyperlipidemia.
33. What is nephritic syndrome? Answer: A syndrome characterized by
hematuria, hypertension, oliguria, and mild to moderate proteinuria, often due to
glomerular inflammation.
34. What is the renal threshold for glucose? Answer: The renal threshold for
glucose is approximately 180-200 mg/dL; above this level, glucose appears in
the urine (glycosuria).
35. What is the macula densa? Answer: Specialized cells in the distal tubule
that sense sodium chloride concentration and regulate renin release and GFR.
