Bio 265 9.2 Exam with Questions & Answers (Grade A+),
Domain 1: Renal Anatomy & Physiology (The Urinary System)
Focus: Filtration, reabsorption, secretion, and urine concentration.
1. The functional unit of the kidney responsible for urine production is the:
A) Neuron
B) Nephron
C) Alveolus
D) Glomerulus
Answer: B
Rationale: The nephron is the microscopic structural and functional unit of the
kidney. Each kidney contains about 1 million nephrons that filter blood and
produce urine [citation:1]. The glomerulus is just one part of the nephron (the
filtration capillary bed).
,2. Blood enters the kidney through the renal artery, then flows into progressively
smaller arteries. What is the correct order of blood flow starting from the renal
artery?
A) Renal artery → Arcuate a. → Interlobar a. → Afferent arteriole
B) Renal artery → Interlobar a. → Arcuate a. → Afferent arteriole
C) Renal artery → Afferent arteriole → Peritubular capillaries → Glomerulus
D) Renal artery → Segmental a. → Interlobar a. → Arcuate a.
Answer: B
Rationale: The correct pathway is: Renal artery → Segmental arteries →
Interlobar arteries → Arcuate arteries → Cortical radiate (interlobular) arteries →
Afferent arterioles → Glomerulus [citation:2].
3. What is the primary force that drives glomerular filtration (Glomerular
Filtration Rate - GFR)?
A) Osmotic pressure of plasma proteins
B) Active transport of sodium
C) Hydrostatic pressure of blood (blood pressure)
D) Suction created by the renal medulla
,Answer: C
Rationale: Glomerular filtration is a passive process driven by the hydrostatic
pressure of the blood inside the glomerular capillaries. This pressure forces water
and small solutes out of the blood and into Bowman's capsule.
4. Which of the following substances is NOT normally found in urine if the kidneys
are functioning correctly?
A) Urea
B) Sodium
C) Glucose
D) Creatinine
Answer: C
Rationale: Glucose is completely reabsorbed in the Proximal Convoluted Tubule
(PCT) via sodium-glucose cotransporters (SGLT). Glucose should only appear in
urine (glycosuria) if blood glucose levels exceed the renal threshold (usually above
~180 mg/dL).
5. The loop of Henle establishes an osmotic gradient in the medulla, which allows
the kidneys to concentrate urine. This mechanism is called the:
A) Countercurrent multiplier
, B) Renin-angiotensin mechanism
C) Tubuloglomerular feedback
D) Micturition reflex
Answer: A
Rationale: The countercurrent multiplier describes how the descending and
ascending limbs of the loop of Henle, running parallel to each other, create a
gradient of increasing sodium concentration from the cortex down to the
medulla. This allows water to be reabsorbed from the collecting duct.
Domain 2: Fluid, Electrolyte, & Acid-Base Balance
Focus: pH regulation, electrolyte homeostasis, and hormones.
6. A patient with emphysema is retaining CO₂ due to hypoventilation. This patient
is likely to be in a state of:
A) Metabolic alkalosis
B) Metabolic acidosis
C) Respiratory alkalosis
D) Respiratory acidosis
Domain 1: Renal Anatomy & Physiology (The Urinary System)
Focus: Filtration, reabsorption, secretion, and urine concentration.
1. The functional unit of the kidney responsible for urine production is the:
A) Neuron
B) Nephron
C) Alveolus
D) Glomerulus
Answer: B
Rationale: The nephron is the microscopic structural and functional unit of the
kidney. Each kidney contains about 1 million nephrons that filter blood and
produce urine [citation:1]. The glomerulus is just one part of the nephron (the
filtration capillary bed).
,2. Blood enters the kidney through the renal artery, then flows into progressively
smaller arteries. What is the correct order of blood flow starting from the renal
artery?
A) Renal artery → Arcuate a. → Interlobar a. → Afferent arteriole
B) Renal artery → Interlobar a. → Arcuate a. → Afferent arteriole
C) Renal artery → Afferent arteriole → Peritubular capillaries → Glomerulus
D) Renal artery → Segmental a. → Interlobar a. → Arcuate a.
Answer: B
Rationale: The correct pathway is: Renal artery → Segmental arteries →
Interlobar arteries → Arcuate arteries → Cortical radiate (interlobular) arteries →
Afferent arterioles → Glomerulus [citation:2].
3. What is the primary force that drives glomerular filtration (Glomerular
Filtration Rate - GFR)?
A) Osmotic pressure of plasma proteins
B) Active transport of sodium
C) Hydrostatic pressure of blood (blood pressure)
D) Suction created by the renal medulla
,Answer: C
Rationale: Glomerular filtration is a passive process driven by the hydrostatic
pressure of the blood inside the glomerular capillaries. This pressure forces water
and small solutes out of the blood and into Bowman's capsule.
4. Which of the following substances is NOT normally found in urine if the kidneys
are functioning correctly?
A) Urea
B) Sodium
C) Glucose
D) Creatinine
Answer: C
Rationale: Glucose is completely reabsorbed in the Proximal Convoluted Tubule
(PCT) via sodium-glucose cotransporters (SGLT). Glucose should only appear in
urine (glycosuria) if blood glucose levels exceed the renal threshold (usually above
~180 mg/dL).
5. The loop of Henle establishes an osmotic gradient in the medulla, which allows
the kidneys to concentrate urine. This mechanism is called the:
A) Countercurrent multiplier
, B) Renin-angiotensin mechanism
C) Tubuloglomerular feedback
D) Micturition reflex
Answer: A
Rationale: The countercurrent multiplier describes how the descending and
ascending limbs of the loop of Henle, running parallel to each other, create a
gradient of increasing sodium concentration from the cortex down to the
medulla. This allows water to be reabsorbed from the collecting duct.
Domain 2: Fluid, Electrolyte, & Acid-Base Balance
Focus: pH regulation, electrolyte homeostasis, and hormones.
6. A patient with emphysema is retaining CO₂ due to hypoventilation. This patient
is likely to be in a state of:
A) Metabolic alkalosis
B) Metabolic acidosis
C) Respiratory alkalosis
D) Respiratory acidosis
