Portage Learning BIOD 152: Urinary System & Acid-Base Balance Exam
2026/2027 UPDATE
1. Which of the following is the functional unit of the kidney responsible for
urine formation?
A. Nephron
B. Renal pelvis
C. Ureter
D. Major calyx
Answer: A
Rationale: The nephron is the structural and functional unit of the kidney; each kidney
contains approximately one million nephrons.
2. The kidneys are located in which space within the abdominal cavity?
A. Intraperitoneal
B. Pleural
C. Mediastinum
D. Retroperitoneal
Answer: D
Rationale: The kidneys are retroperitoneal, meaning they are located behind the parietal
peritoneum against the posterior abdominal wall.
,3. Which hormone is primarily responsible for increasing water reabsorption in
the collecting ducts?
A. Atrial Natriuretic Peptide (ANP)
B. Aldosterone
C. Antidiuretic Hormone (ADH)
D. Epinephrine
Answer: C
Rationale: ADH (vasopressin) increases the permeability of the collecting ducts to water
by inserting aquaporins, leading to water retention.
4. What is the primary driving force behind glomerular filtration?
A. Capsular osmotic pressure
B. Active transport
C. Glomerular hydrostatic pressure
D. Colloid osmotic pressure
Answer: C
Rationale: Glomerular hydrostatic pressure (blood pressure in the capillaries) pushes
water and solutes out of the blood and into the glomerular capsule.
5. In which part of the nephron does the majority of nutrient reabsorption (like
glucose and amino acids) occur?
A. Loop of Henle
B. Distal Convoluted Tubule (DCT)
C. Proximal Convoluted Tubule (PCT)
D. Collecting Duct
Answer: C
Rationale: The PCT is responsible for reabsorbing about 65% of water and sodium, and
nearly 100% of glucose and amino acids.
, 6. Which cells in the juxtaglomerular apparatus act as mechanoreceptors to
sense blood pressure in the afferent arteriole?
A. Macula densa cells
B. Juxtaglomerular (JG) cells
C. Mesangial cells
D. Podocytes
Answer: B
Rationale: JG cells are enlarged smooth muscle cells in the afferent arteriole that sense
blood pressure and secrete renin.
7. A patient’s blood pH is 7.25, and PCO2 is elevated. This condition is known as:
A. Respiratory Acidosis
B. Metabolic Alkalosis
C. Respiratory Alkalosis
D. Metabolic Acidosis
Answer: A
Rationale: A pH below 7.35 indicates acidosis. If the PCO2 is high, it indicates the cause is
respiratory (hypoventilation).
8. The presence of which of the following in a urinalysis would most likely
indicate a urinary tract infection (UTI)?
A. Glucose
B. Ketones
C. Urobilinogen
D. Nitrites and Leukocytes
Answer: D
Rationale: Bacteria that cause UTIs often convert nitrates to nitrites, and leukocytes
(WBCs) indicate an immune response to infection.
2026/2027 UPDATE
1. Which of the following is the functional unit of the kidney responsible for
urine formation?
A. Nephron
B. Renal pelvis
C. Ureter
D. Major calyx
Answer: A
Rationale: The nephron is the structural and functional unit of the kidney; each kidney
contains approximately one million nephrons.
2. The kidneys are located in which space within the abdominal cavity?
A. Intraperitoneal
B. Pleural
C. Mediastinum
D. Retroperitoneal
Answer: D
Rationale: The kidneys are retroperitoneal, meaning they are located behind the parietal
peritoneum against the posterior abdominal wall.
,3. Which hormone is primarily responsible for increasing water reabsorption in
the collecting ducts?
A. Atrial Natriuretic Peptide (ANP)
B. Aldosterone
C. Antidiuretic Hormone (ADH)
D. Epinephrine
Answer: C
Rationale: ADH (vasopressin) increases the permeability of the collecting ducts to water
by inserting aquaporins, leading to water retention.
4. What is the primary driving force behind glomerular filtration?
A. Capsular osmotic pressure
B. Active transport
C. Glomerular hydrostatic pressure
D. Colloid osmotic pressure
Answer: C
Rationale: Glomerular hydrostatic pressure (blood pressure in the capillaries) pushes
water and solutes out of the blood and into the glomerular capsule.
5. In which part of the nephron does the majority of nutrient reabsorption (like
glucose and amino acids) occur?
A. Loop of Henle
B. Distal Convoluted Tubule (DCT)
C. Proximal Convoluted Tubule (PCT)
D. Collecting Duct
Answer: C
Rationale: The PCT is responsible for reabsorbing about 65% of water and sodium, and
nearly 100% of glucose and amino acids.
, 6. Which cells in the juxtaglomerular apparatus act as mechanoreceptors to
sense blood pressure in the afferent arteriole?
A. Macula densa cells
B. Juxtaglomerular (JG) cells
C. Mesangial cells
D. Podocytes
Answer: B
Rationale: JG cells are enlarged smooth muscle cells in the afferent arteriole that sense
blood pressure and secrete renin.
7. A patient’s blood pH is 7.25, and PCO2 is elevated. This condition is known as:
A. Respiratory Acidosis
B. Metabolic Alkalosis
C. Respiratory Alkalosis
D. Metabolic Acidosis
Answer: A
Rationale: A pH below 7.35 indicates acidosis. If the PCO2 is high, it indicates the cause is
respiratory (hypoventilation).
8. The presence of which of the following in a urinalysis would most likely
indicate a urinary tract infection (UTI)?
A. Glucose
B. Ketones
C. Urobilinogen
D. Nitrites and Leukocytes
Answer: D
Rationale: Bacteria that cause UTIs often convert nitrates to nitrites, and leukocytes
(WBCs) indicate an immune response to infection.
