QUESTIONS WITH CORRECT ANSWERS AND
RATIONALES FULLY SOLVED AND UPDATED
(LATEST UPDATE 2026 UPDATE)!!!
SECTION 1: KIDNEY ANATOMY, PHYSIOLOGY, AND ESRD FUNDAMENTALS (1-25)
1: A PCT is explaining kidney function to a newly diagnosed ESRD patient. The
patient asks which structure is considered the basic structural and functional unit
of the kidney. Which response by the PCT is correct?
A. The renal cortex
B. The nephron
C. The renal pelvis
D. The glomerular capsule only
Correct Answer: B
Rationale: The nephron is the basic structural and functional unit of the kidney,
with approximately one million nephrons per kidney responsible for filtering blood
and producing urine. The cortex, pelvis, and capsule are anatomical structures but
,do not independently perform filtration; the nephron (comprising the glomerulus
and tubular system) is the functional unit that produces urine through filtration,
reabsorption, and secretion.
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2: A normal kidney contains approximately how many nephrons per kidney?
A. Approximately 100,000
B. Approximately 500,000
C. Approximately 1 million
D. Approximately 5 million
Correct Answer: C
Rationale: Each kidney contains approximately one million nephrons. This large
nephron reserve explains why kidney disease often progresses silently, as
significant function can be lost before symptoms appear. Once nephron loss
reaches a critical threshold, ESRD develops, reuiring dialysis or transplant to
sustain life.
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3: A patient's lab results show a GFR of 12 mL/min/1.73m². The PCT understands
that this value meets the criteria for which condition?
,A. Chronic kidney disease stage 3
B. Chronic kidney disease stage 4
C. End-stage renal disease (ESRD)
D. Acute kidney injury stage 2
Correct Answer: C
Rationale: A GFR below 15 mL/min/1.73m² meets the criteria for End-Stage Renal
Disease (ESRD). Stage 3 CKD is GFR 30-59, Stage 4 is GFR 15-29. ESRD indicates the
kidneys have permanently lost nearly all function, reuiring renal replacement
therapy such as hemodialysis, peritoneal dialysis, or transplantation to sustain life.
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4: Which of the following is an endocrine function of the kidneys?
A. Filtration of urea and creatinine
B. Regulation of fluid volume
C. Secretion of renin and erythropoietin
D. Removal of metabolic waste products
Correct Answer: C
, Rationale: The kidneys have both excretory and endocrine functions. The
endocrine functions include: 1) renin secretion (regulates blood pressure), 2)
erythropoietin secretion (stimulates red blood cell production), and 3) activation
of vitamin D (calcium homeostasis). Options A, B, and D describe excretory
functions of the kidneys.
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5: A patient asks why their anemia is related to kidney failure. The PCT explains
that the kidneys produce a hormone that stimulates red blood cell production.
This hormone is called:
A. Renin
B. Aldosterone
C. Erythropoietin
D. Calcitonin
Correct Answer: C
Rationale: Erythropoietin (EPO) is a hormone produced by the kidneys that
stimulates the bone marrow to produce red blood cells. In kidney failure, EPO
production decreases, leading to anemia. This is why many ESRD patients reuire
erythropoiesis-stimulating agents (ESAs) to manage anemia. Renin (A) regulates
blood pressure, aldosterone (B) regulates sodium, and calcitonin (D) regulates
calcium.