NURS 231/NURS231 Module 8 V3 |
Pathophysiology Q&A with Rationale | Portage
Learning
1. Which part of the nephron is primarily responsible for the majority of water and solute
reabsorption?
A. Loop of Henle
B. Distal Convoluted Tubule
C. Proximal Convoluted Tubule
D. Collecting Duct
Correct Answer: C
Explanation: The proximal convoluted tubule is responsible for reabsorbing
approximately 65% of filtered water and electrolytes. It contains a brush border of
microvilli that significantly increases the surface area for absorption. This section of the
nephron is vital for maintaining fluid balance and recovering essential nutrients like
glucose and amino acids.
2. In the context of Acute Kidney Injury (AKI), which of the following is considered a pre-renal
cause?
A. Bladder outlet obstruction
B. Acute Tubular Necrosis (ATN)
,C. Hypovolemia due to severe dehydration
D. Exposure to nephrotoxic medications
Correct Answer: C
Explanation: Pre-renal causes of AKI are related to factors that decrease blood flow to the
kidneys before it reaches the renal tissue. Hypovolemia reduces the perfusion pressure
required for effective glomerular filtration. If these conditions are corrected promptly, the
kidney function often returns to baseline without permanent damage.
3. A patient presents with massive proteinuria (>3.5 g/day), hypoalbuminemia, and
generalized edema. Which condition is most likely?
A. Acute Nephritic Syndrome
B. Nephrotic Syndrome
C. Pyelonephritis
D. Renal Calculi
Correct Answer: B
Explanation: Nephrotic syndrome is characterized by increased glomerular permeability
to plasma proteins, leading to heavy proteinuria. The loss of albumin reduces plasma
oncotic pressure, resulting in the movement of fluid into the interstitial space and causing
edema. Hyperlipidemia is also a common compensatory finding in this syndrome due to
increased liver lipoprotein synthesis.
, 4. What is the primary stimulus for the release of erythropoietin by the kidneys?
A. Hyperkalemia
B. Hyperglycemia
C. Hypoxemia (low oxygen levels)
D. Low serum sodium levels
Correct Answer: C
Explanation: Erythropoietin is a hormone produced by the interstitial fibroblasts in the
kidney in response to low oxygen delivery. It acts on the bone marrow to stimulate the
production of red blood cells to increase oxygen-carrying capacity. In chronic kidney
disease, the lack of this hormone leads to significant anemia.
5. Which hormone acts on the distal tubule and collecting duct to increase water
reabsorption without affecting sodium levels?
A. Aldosterone
B. Antidiuretic Hormone (ADH)
C. Atrial Natriuretic Peptide (ANP)
D. Parathyroid Hormone (PTH)
Correct Answer: B
Explanation: Antidiuretic Hormone (ADH), also known as vasopressin, regulates water
permeability in the collecting ducts through aquaporin channels. Unlike aldosterone, which
Pathophysiology Q&A with Rationale | Portage
Learning
1. Which part of the nephron is primarily responsible for the majority of water and solute
reabsorption?
A. Loop of Henle
B. Distal Convoluted Tubule
C. Proximal Convoluted Tubule
D. Collecting Duct
Correct Answer: C
Explanation: The proximal convoluted tubule is responsible for reabsorbing
approximately 65% of filtered water and electrolytes. It contains a brush border of
microvilli that significantly increases the surface area for absorption. This section of the
nephron is vital for maintaining fluid balance and recovering essential nutrients like
glucose and amino acids.
2. In the context of Acute Kidney Injury (AKI), which of the following is considered a pre-renal
cause?
A. Bladder outlet obstruction
B. Acute Tubular Necrosis (ATN)
,C. Hypovolemia due to severe dehydration
D. Exposure to nephrotoxic medications
Correct Answer: C
Explanation: Pre-renal causes of AKI are related to factors that decrease blood flow to the
kidneys before it reaches the renal tissue. Hypovolemia reduces the perfusion pressure
required for effective glomerular filtration. If these conditions are corrected promptly, the
kidney function often returns to baseline without permanent damage.
3. A patient presents with massive proteinuria (>3.5 g/day), hypoalbuminemia, and
generalized edema. Which condition is most likely?
A. Acute Nephritic Syndrome
B. Nephrotic Syndrome
C. Pyelonephritis
D. Renal Calculi
Correct Answer: B
Explanation: Nephrotic syndrome is characterized by increased glomerular permeability
to plasma proteins, leading to heavy proteinuria. The loss of albumin reduces plasma
oncotic pressure, resulting in the movement of fluid into the interstitial space and causing
edema. Hyperlipidemia is also a common compensatory finding in this syndrome due to
increased liver lipoprotein synthesis.
, 4. What is the primary stimulus for the release of erythropoietin by the kidneys?
A. Hyperkalemia
B. Hyperglycemia
C. Hypoxemia (low oxygen levels)
D. Low serum sodium levels
Correct Answer: C
Explanation: Erythropoietin is a hormone produced by the interstitial fibroblasts in the
kidney in response to low oxygen delivery. It acts on the bone marrow to stimulate the
production of red blood cells to increase oxygen-carrying capacity. In chronic kidney
disease, the lack of this hormone leads to significant anemia.
5. Which hormone acts on the distal tubule and collecting duct to increase water
reabsorption without affecting sodium levels?
A. Aldosterone
B. Antidiuretic Hormone (ADH)
C. Atrial Natriuretic Peptide (ANP)
D. Parathyroid Hormone (PTH)
Correct Answer: B
Explanation: Antidiuretic Hormone (ADH), also known as vasopressin, regulates water
permeability in the collecting ducts through aquaporin channels. Unlike aldosterone, which
