BIOS 255 / BIOS255 Exam 3: Anatomy & Physiology III
with Lab Latest update 2026/2027 | Chamberlain |
Q&A with Rationales | Grade A | Pass Guaranteed
A+ Graded
Question 1
The conversion of Angiotensin I to Angiotensin II occurs primarily in the:
A. Liver
B. Kidney
C. Lungs (via endothelial ACE)
D. Heart
Answer: C
Rationale: Angiotensin-converting enzyme (ACE) is located primarily on the endothelial cells of
the pulmonary capillaries. As Angiotensin I passes through the lungs, it is rapidly converted to
the active Angiotensin II.
Question 2
Which of the following best describes the mechanism of action of Antidiuretic Hormone (ADH)
at the cellular level?
A. It stimulates the synthesis of aquaporin-2 proteins and their insertion into the apical
membrane of collecting duct cells.
B. It activates Na+/K+ pumps in the proximal convoluted tubule.
C. It increases glomerular filtration rate by dilating the afferent arteriole.
D. It inhibits the reabsorption of water in the loop of Henle.
Answer: A
,Rationale: ADH binds to V2 receptors on the principal cells of the collecting duct, triggering a
cAMP second messenger system that leads to the insertion of aquaporin-2 channels into the
luminal membrane. This allows water to be reabsorbed back into the hypertonic medullary
interstitium.
Question 3
A patient presents with blood work showing pH 7.30, PaCO2 50 mmHg, and HCO3- 30 mEq/L.
How would you interpret this ABG result?
A. Uncompensated respiratory acidosis
B. Partially compensated respiratory acidosis
C. Uncompensated metabolic alkalosis
D. Partially compensated metabolic alkalosis
Answer: B
Rationale: The pH is acidic (<7.35), and the cause is respiratory (PaCO2 is high). The HCO3- is
elevated (>26), indicating the kidneys are retaining bicarbonate to buffer the acid. Since the pH
has not returned to the normal range (7.35-7.45), it is only partially compensated.
Question 4
Which of the following pancreatic enzymes is responsible for breaking down proteins into
peptides in the small intestine?
A. Pancreatic amylase
B. Pancreatic lipase
C. Trypsin
D. Nuclease
Answer: C
Rationale: Trypsin (and chymotrypsin) are proteases secreted by the pancreas that break proteins
down into smaller peptides. Amylase breaks down carbohydrates and lipase breaks down fats.
, Question 5
In the context of fluid compartments, if a patient consumes a large amount of pure water without
electrolytes, what happens to the intracellular fluid (ICF) volume?
A. ICF volume decreases.
B. ICF volume increases.
C. ICF volume remains unchanged while ECF decreases.
D. Both ICF and ECF decrease equally.
Answer: B
Rationale: Consuming pure water dilutes the ECF (hypotonicity). Water then moves by osmosis
from the ECF (lower solute concentration) into the ICF (higher solute concentration) to restore
equilibrium. This causes cells to swell.
Question 6
Select all that apply: Which of the following are true regarding the function of the Vasa Recta?
A. They supply blood to the nephron loop (loop of Henle) and collecting duct.
B. They remove water and solutes from the medullary interstitium.
C. They maintain the medullary osmotic gradient by a countercurrent exchange mechanism.
D. They are highly permeable to water and solutes.
E. They are found only in cortical nephrons.
Answer: A, B, C, D
Rationale: The Vasa Recta are the peritubular capillaries associated with juxtamedullary
nephrons (not cortical nephrons, so E is false). They maintain the gradient by exchanging water
and solutes without washing out the accumulated salts in the medulla (countercurrent exchange).
They also supply nutrients and remove reabsorbed water and solutes.
with Lab Latest update 2026/2027 | Chamberlain |
Q&A with Rationales | Grade A | Pass Guaranteed
A+ Graded
Question 1
The conversion of Angiotensin I to Angiotensin II occurs primarily in the:
A. Liver
B. Kidney
C. Lungs (via endothelial ACE)
D. Heart
Answer: C
Rationale: Angiotensin-converting enzyme (ACE) is located primarily on the endothelial cells of
the pulmonary capillaries. As Angiotensin I passes through the lungs, it is rapidly converted to
the active Angiotensin II.
Question 2
Which of the following best describes the mechanism of action of Antidiuretic Hormone (ADH)
at the cellular level?
A. It stimulates the synthesis of aquaporin-2 proteins and their insertion into the apical
membrane of collecting duct cells.
B. It activates Na+/K+ pumps in the proximal convoluted tubule.
C. It increases glomerular filtration rate by dilating the afferent arteriole.
D. It inhibits the reabsorption of water in the loop of Henle.
Answer: A
,Rationale: ADH binds to V2 receptors on the principal cells of the collecting duct, triggering a
cAMP second messenger system that leads to the insertion of aquaporin-2 channels into the
luminal membrane. This allows water to be reabsorbed back into the hypertonic medullary
interstitium.
Question 3
A patient presents with blood work showing pH 7.30, PaCO2 50 mmHg, and HCO3- 30 mEq/L.
How would you interpret this ABG result?
A. Uncompensated respiratory acidosis
B. Partially compensated respiratory acidosis
C. Uncompensated metabolic alkalosis
D. Partially compensated metabolic alkalosis
Answer: B
Rationale: The pH is acidic (<7.35), and the cause is respiratory (PaCO2 is high). The HCO3- is
elevated (>26), indicating the kidneys are retaining bicarbonate to buffer the acid. Since the pH
has not returned to the normal range (7.35-7.45), it is only partially compensated.
Question 4
Which of the following pancreatic enzymes is responsible for breaking down proteins into
peptides in the small intestine?
A. Pancreatic amylase
B. Pancreatic lipase
C. Trypsin
D. Nuclease
Answer: C
Rationale: Trypsin (and chymotrypsin) are proteases secreted by the pancreas that break proteins
down into smaller peptides. Amylase breaks down carbohydrates and lipase breaks down fats.
, Question 5
In the context of fluid compartments, if a patient consumes a large amount of pure water without
electrolytes, what happens to the intracellular fluid (ICF) volume?
A. ICF volume decreases.
B. ICF volume increases.
C. ICF volume remains unchanged while ECF decreases.
D. Both ICF and ECF decrease equally.
Answer: B
Rationale: Consuming pure water dilutes the ECF (hypotonicity). Water then moves by osmosis
from the ECF (lower solute concentration) into the ICF (higher solute concentration) to restore
equilibrium. This causes cells to swell.
Question 6
Select all that apply: Which of the following are true regarding the function of the Vasa Recta?
A. They supply blood to the nephron loop (loop of Henle) and collecting duct.
B. They remove water and solutes from the medullary interstitium.
C. They maintain the medullary osmotic gradient by a countercurrent exchange mechanism.
D. They are highly permeable to water and solutes.
E. They are found only in cortical nephrons.
Answer: A, B, C, D
Rationale: The Vasa Recta are the peritubular capillaries associated with juxtamedullary
nephrons (not cortical nephrons, so E is false). They maintain the gradient by exchanging water
and solutes without washing out the accumulated salts in the medulla (countercurrent exchange).
They also supply nutrients and remove reabsorbed water and solutes.
