NUR 631 Renal Exam 2026/2027 – Comprehensive
Complete Questions & Verified Answers with
Rationales
Section I: Renal Anatomy, Physiology & Hemodynamics
1. Which structure is the primary site of glomerular filtration?
A. Loop of Henle
B. Glomerulus
C. Collecting duct
D. Distal convoluted tubule
Answer: B
Rationale: The glomerulus is a capillary network where plasma is filtered into
Bowman's space. The tubular system subsequently modifies the filtrate.
2. Which component of the renal filtration barrier provides the greatest
selectivity against large plasma proteins?
A. Glomerular basement membrane and podocyte slit diaphragm
B. Renal pelvis
C. Collecting duct
D. Ureteral epithelium
Answer: A
Rationale: The filtration barrier consists of fenestrated endothelium, basement
membrane, and podocyte slit diaphragms. Together they restrict filtration of large
and negatively charged proteins.
,3. Glomerular filtration rate is most directly influenced by:
A. Net filtration pressure and filtration coefficient
B. Gastric acid secretion
C. Pulmonary diffusion
D. Hepatic bile production
Answer: A
Rationale: GFR depends on the balance of hydrostatic and oncotic pressures
across the glomerulus and the permeability/surface area of the filtration barrier.
4. Which change generally increases GFR, assuming other factors remain
constant?
A. Increased Bowman's space hydrostatic pressure
B. Increased glomerular capillary hydrostatic pressure
C. Increased plasma oncotic pressure
D. Severe afferent arteriolar constriction
Answer: B
Rationale: Higher glomerular capillary hydrostatic pressure favors filtration and
can increase GFR.
5. Constriction of the afferent arteriole generally causes:
A. Increased renal blood flow and GFR
B. Reduced renal blood flow and GFR
C. Increased GFR with no change in renal blood flow
D. Increased tubular reabsorption only
Answer: B
Rationale: Afferent constriction reduces blood entering the glomerulus, lowering
glomerular pressure, renal blood flow, and generally GFR.
,6. Moderate efferent arteriolar constriction can initially:
A. Increase glomerular capillary pressure
B. Eliminate filtration
C. Decrease plasma oncotic pressure
D. Stop renal blood flow completely
Answer: A
Rationale: Moderate efferent constriction raises pressure within glomerular
capillaries and can support GFR, although severe constriction can eventually
reduce renal blood flow and filtration.
7. Which hormone directly increases water permeability in the collecting duct?
A. Aldosterone
B. ADH
C. Renin
D. Erythropoietin
Answer: B
Rationale: ADH stimulates insertion of aquaporin-2 water channels into collecting
duct principal-cell membranes.
8. Aldosterone acts primarily on the:
A. Glomerulus
B. Distal nephron and collecting duct
C. Renal pelvis
D. Proximal ureter
Answer: B
Rationale: Aldosterone increases sodium reabsorption and potassium secretion
primarily in principal cells of the late distal nephron and collecting duct.
, 9. Which renal process returns filtered substances from tubular fluid to the
blood?
A. Secretion
B. Reabsorption
C. Filtration
D. Excretion
Answer: B
Rationale: Reabsorption transfers substances from the tubular lumen back into
the peritubular circulation.
10. Which process moves substances from blood into tubular fluid?
A. Reabsorption
B. Secretion
C. Filtration only
D. Osmosis only
Answer: B
Rationale: Tubular secretion transfers substances such as hydrogen ions,
potassium, and certain medications from blood into the tubular lumen.
11. Which nephron segment normally reabsorbs the largest proportion of
filtered sodium and water?
A. Proximal tubule
B. Thin ascending limb
C. Distal convoluted tubule
D. Collecting duct
Answer: A
Rationale: The proximal tubule performs bulk reabsorption of sodium, water,
bicarbonate, glucose, amino acids, and other filtered substances.
Complete Questions & Verified Answers with
Rationales
Section I: Renal Anatomy, Physiology & Hemodynamics
1. Which structure is the primary site of glomerular filtration?
A. Loop of Henle
B. Glomerulus
C. Collecting duct
D. Distal convoluted tubule
Answer: B
Rationale: The glomerulus is a capillary network where plasma is filtered into
Bowman's space. The tubular system subsequently modifies the filtrate.
2. Which component of the renal filtration barrier provides the greatest
selectivity against large plasma proteins?
A. Glomerular basement membrane and podocyte slit diaphragm
B. Renal pelvis
C. Collecting duct
D. Ureteral epithelium
Answer: A
Rationale: The filtration barrier consists of fenestrated endothelium, basement
membrane, and podocyte slit diaphragms. Together they restrict filtration of large
and negatively charged proteins.
,3. Glomerular filtration rate is most directly influenced by:
A. Net filtration pressure and filtration coefficient
B. Gastric acid secretion
C. Pulmonary diffusion
D. Hepatic bile production
Answer: A
Rationale: GFR depends on the balance of hydrostatic and oncotic pressures
across the glomerulus and the permeability/surface area of the filtration barrier.
4. Which change generally increases GFR, assuming other factors remain
constant?
A. Increased Bowman's space hydrostatic pressure
B. Increased glomerular capillary hydrostatic pressure
C. Increased plasma oncotic pressure
D. Severe afferent arteriolar constriction
Answer: B
Rationale: Higher glomerular capillary hydrostatic pressure favors filtration and
can increase GFR.
5. Constriction of the afferent arteriole generally causes:
A. Increased renal blood flow and GFR
B. Reduced renal blood flow and GFR
C. Increased GFR with no change in renal blood flow
D. Increased tubular reabsorption only
Answer: B
Rationale: Afferent constriction reduces blood entering the glomerulus, lowering
glomerular pressure, renal blood flow, and generally GFR.
,6. Moderate efferent arteriolar constriction can initially:
A. Increase glomerular capillary pressure
B. Eliminate filtration
C. Decrease plasma oncotic pressure
D. Stop renal blood flow completely
Answer: A
Rationale: Moderate efferent constriction raises pressure within glomerular
capillaries and can support GFR, although severe constriction can eventually
reduce renal blood flow and filtration.
7. Which hormone directly increases water permeability in the collecting duct?
A. Aldosterone
B. ADH
C. Renin
D. Erythropoietin
Answer: B
Rationale: ADH stimulates insertion of aquaporin-2 water channels into collecting
duct principal-cell membranes.
8. Aldosterone acts primarily on the:
A. Glomerulus
B. Distal nephron and collecting duct
C. Renal pelvis
D. Proximal ureter
Answer: B
Rationale: Aldosterone increases sodium reabsorption and potassium secretion
primarily in principal cells of the late distal nephron and collecting duct.
, 9. Which renal process returns filtered substances from tubular fluid to the
blood?
A. Secretion
B. Reabsorption
C. Filtration
D. Excretion
Answer: B
Rationale: Reabsorption transfers substances from the tubular lumen back into
the peritubular circulation.
10. Which process moves substances from blood into tubular fluid?
A. Reabsorption
B. Secretion
C. Filtration only
D. Osmosis only
Answer: B
Rationale: Tubular secretion transfers substances such as hydrogen ions,
potassium, and certain medications from blood into the tubular lumen.
11. Which nephron segment normally reabsorbs the largest proportion of
filtered sodium and water?
A. Proximal tubule
B. Thin ascending limb
C. Distal convoluted tubule
D. Collecting duct
Answer: A
Rationale: The proximal tubule performs bulk reabsorption of sodium, water,
bicarbonate, glucose, amino acids, and other filtered substances.
