BIOL 252 Human Anatomy &
Physiology II w/Lab 2026| Module 2
Urinary System & Kidneys |100+
Questions and Answers with Rationales
1. Which organ is the primary site of filtration in the urinary
system?
A. Ureter
B. Urinary bladder
C. Kidney
D. Urethra
Answer: C. Kidney
Rationale: The kidneys filter blood, remove wastes, regulate fluid
balance, and produce urine.
2. The functional unit of the kidney is the:
A. Neuron
B. Alveolus
C. Nephron
D. Glomerulus
Answer: C. Nephron
Rationale: Each kidney contains approximately one million nephrons
responsible for filtering blood and forming urine.
3. Which structure directly surrounds the glomerulus?
,A. Loop of Henle
B. Collecting duct
C. Distal convoluted tubule
D. Bowman's capsule
Answer: D. Bowman's capsule
Rationale: Bowman's capsule encloses the glomerulus and collects
the filtrate.
4. Blood enters the glomerulus through the:
A. Efferent arteriole
B. Renal vein
C. Afferent arteriole
D. Peritubular capillary
Answer: C. Afferent arteriole
Rationale: The afferent arteriole delivers blood into the glomerular
capillaries.
5. Blood leaves the glomerulus through the:
A. Renal artery
B. Venule
C. Efferent arteriole
D. Collecting duct
Answer: C. Efferent arteriole
Rationale: The efferent arteriole carries filtered blood away from the
glomerulus.
6. Filtration occurs in the:
,A. Collecting duct
B. Loop of Henle
C. Distal tubule
D. Renal corpuscle
Answer: D. Renal corpuscle
Rationale: The renal corpuscle consists of the glomerulus and
Bowman's capsule where filtration begins.
7. Which process moves water and small solutes from blood into
Bowman's capsule?
A. Secretion
B. Reabsorption
C. Diffusion
D. Glomerular filtration
Answer: D. Glomerular filtration
Rationale: Hydrostatic pressure forces water and small molecules into
the nephron.
8. Which substance is normally NOT filtered into the nephron?
A. Glucose
B. Sodium
C. Water
D. Red blood cells
Answer: D. Red blood cells
Rationale: Blood cells are too large to pass through the filtration
membrane.
, 9. The majority of water reabsorption occurs in the:
A. Collecting duct
B. Distal convoluted tubule
C. Loop of Henle
D. Proximal convoluted tubule
Answer: D. Proximal convoluted tubule
Rationale: Approximately 65–70% of filtered water is reabsorbed in
the proximal tubule.
10. Which nephron segment is highly permeable to water?
A. Ascending loop of Henle
B. Distal tubule
C. Descending loop of Henle
D. Collecting duct
Answer: C. Descending loop of Henle
Rationale: Water leaves the descending limb by osmosis.
11. The ascending limb of the loop of Henle primarily reabsorbs:
A. Water only
B. Proteins
C. Glucose
D. Sodium and chloride
Answer: D. Sodium and chloride
Rationale: The ascending limb actively transports Na⁺ and Cl⁻ but is
impermeable to water.
Physiology II w/Lab 2026| Module 2
Urinary System & Kidneys |100+
Questions and Answers with Rationales
1. Which organ is the primary site of filtration in the urinary
system?
A. Ureter
B. Urinary bladder
C. Kidney
D. Urethra
Answer: C. Kidney
Rationale: The kidneys filter blood, remove wastes, regulate fluid
balance, and produce urine.
2. The functional unit of the kidney is the:
A. Neuron
B. Alveolus
C. Nephron
D. Glomerulus
Answer: C. Nephron
Rationale: Each kidney contains approximately one million nephrons
responsible for filtering blood and forming urine.
3. Which structure directly surrounds the glomerulus?
,A. Loop of Henle
B. Collecting duct
C. Distal convoluted tubule
D. Bowman's capsule
Answer: D. Bowman's capsule
Rationale: Bowman's capsule encloses the glomerulus and collects
the filtrate.
4. Blood enters the glomerulus through the:
A. Efferent arteriole
B. Renal vein
C. Afferent arteriole
D. Peritubular capillary
Answer: C. Afferent arteriole
Rationale: The afferent arteriole delivers blood into the glomerular
capillaries.
5. Blood leaves the glomerulus through the:
A. Renal artery
B. Venule
C. Efferent arteriole
D. Collecting duct
Answer: C. Efferent arteriole
Rationale: The efferent arteriole carries filtered blood away from the
glomerulus.
6. Filtration occurs in the:
,A. Collecting duct
B. Loop of Henle
C. Distal tubule
D. Renal corpuscle
Answer: D. Renal corpuscle
Rationale: The renal corpuscle consists of the glomerulus and
Bowman's capsule where filtration begins.
7. Which process moves water and small solutes from blood into
Bowman's capsule?
A. Secretion
B. Reabsorption
C. Diffusion
D. Glomerular filtration
Answer: D. Glomerular filtration
Rationale: Hydrostatic pressure forces water and small molecules into
the nephron.
8. Which substance is normally NOT filtered into the nephron?
A. Glucose
B. Sodium
C. Water
D. Red blood cells
Answer: D. Red blood cells
Rationale: Blood cells are too large to pass through the filtration
membrane.
, 9. The majority of water reabsorption occurs in the:
A. Collecting duct
B. Distal convoluted tubule
C. Loop of Henle
D. Proximal convoluted tubule
Answer: D. Proximal convoluted tubule
Rationale: Approximately 65–70% of filtered water is reabsorbed in
the proximal tubule.
10. Which nephron segment is highly permeable to water?
A. Ascending loop of Henle
B. Distal tubule
C. Descending loop of Henle
D. Collecting duct
Answer: C. Descending loop of Henle
Rationale: Water leaves the descending limb by osmosis.
11. The ascending limb of the loop of Henle primarily reabsorbs:
A. Water only
B. Proteins
C. Glucose
D. Sodium and chloride
Answer: D. Sodium and chloride
Rationale: The ascending limb actively transports Na⁺ and Cl⁻ but is
impermeable to water.
