NR507 | NR507 Advanced Pathophysiology
Midterm v3 | Questions with Correct Answers and
Expert Explanation for Each Question |
Chamberlain
1. A patient is diagnosed with cellular atrophy. Which of the following best describes this
process?
A. An increase in the number of cells in an organ.
B. The replacement of one adult cell type by another.
C. A decrease in cell size leading to reduced tissue mass.
D. Abnormal changes in the size, shape, and organization of cells.
Correct Answer: C
Expert Explanation: Cellular atrophy occurs when there is a decrease in cell size, which
often leads to the shrinkage of an entire organ. This process can be physiological, such as
the shrinkage of the thymus during childhood, or pathological due to disuse or ischemia. It
is distinct from hyperplasia, which involves an increase in the number of cells.
2. Which electrolyte imbalance is most likely to cause a widened QRS complex and peaked T
waves on an ECG?
A. Hyperkalemia
B. Hyponatremia
C. Hypokalemia
D. Hypocalcemia
Correct Answer: A
Expert Explanation: Hyperkalemia, or high serum potassium levels, significantly affects
the cardiac resting membrane potential. Peaked T waves and a widened QRS complex are
classic electrocardiogram findings associated with this condition. If left untreated,
hyperkalemia can progress to lethal arrhythmias such as ventricular fibrillation.
3. Which type of hypersensitivity reaction is mediated by IgE antibodies and involves mast
cell degranulation?
A. Type IV Hypersensitivity
B. Type II Hypersensitivity
C. Type III Hypersensitivity
,D. Type I Hypersensitivity
Correct Answer: D
Expert Explanation: Type I hypersensitivity is an immediate allergic reaction triggered
when an allergen binds to IgE antibodies on mast cells. This binding causes the release of
histamine and other inflammatory mediators, leading to symptoms like itching or
anaphylaxis. It is the primary mechanism behind hay fever and asthma.
4. In the Renin-Angiotensin-Aldosterone System (RAAS), what is the primary function of
Angiotensin II?
A. To promote the excretion of sodium in the kidneys.
B. To decrease systemic blood pressure.
C. To inhibit the secretion of Antidiuretic Hormone (ADH).
D. To cause potent vasoconstriction and stimulate aldosterone release.
Correct Answer: D
Expert Explanation: Angiotensin II is a powerful vasoconstrictor that increases systemic
vascular resistance and blood pressure. It also stimulates the adrenal cortex to release
aldosterone, which promotes sodium and water retention. These combined effects are
crucial for maintaining hemodynamic stability during periods of low perfusion.
5. A patient presents with metabolic acidosis. Which compensatory mechanism would the
body likely employ?
A. Hyperventilation to blow off carbon dioxide.
B. Hypoventilation to retain carbon dioxide.
C. Decreased renal excretion of hydrogen ions.
D. Increased renal reabsorption of chloride.
Correct Answer: A
Expert Explanation: Metabolic acidosis involves a decrease in bicarbonate or an increase
in non-volatile acids in the blood. The respiratory system compensates by increasing the
rate and depth of breathing (hyperventilation) to reduce PCO2 levels. This reduction in CO2
helps to return the blood pH toward a normal range.
6. What is the hallmark characteristic of Malignant tumors compared to Benign tumors?
A. Slow growth and well-defined capsules.
B. A lack of vascularity within the tumor mass.
C. Cells that are well-differentiated and resemble parent tissue.
D. The ability to metastasize and invade surrounding tissues.
, Correct Answer: D
Expert Explanation: Malignant tumors are characterized by rapid growth and the ability
to invade local tissues and spread to distant sites. Unlike benign tumors, they lack a fibrous
capsule and often demonstrate anaplasia, meaning the cells are poorly differentiated.
Metastasis is the most definitive sign of malignancy in clinical pathology.
7. Which deficiency is the primary cause of Pernicious Anemia?
A. Iron deficiency
B. Folic acid deficiency
C. Vitamin B12 deficiency due to lack of intrinsic factor
D. Erythropoietin deficiency
Correct Answer: C
Expert Explanation: Pernicious anemia is a type of megaloblastic anemia caused by the
lack of intrinsic factor, which is necessary for Vitamin B12 absorption. Intrinsic factor is
usually produced by the gastric parietal cells, but autoimmune destruction can inhibit its
production. Without Vitamin B12, DNA synthesis in red blood cells is impaired, leading to
large, immature erythrocytes.
8. What is the primary pathophysiology behind Type 1 Diabetes Mellitus?
A. Autoimmune destruction of pancreatic beta cells.
B. Insulin resistance in peripheral tissues.
C. Excessive secretion of glucagon from alpha cells.
D. Increased hepatic glucose production.
Correct Answer: A
Expert Explanation: Type 1 Diabetes Mellitus is characterized by an absolute insulin
deficiency resulting from the destruction of insulin-producing beta cells in the pancreas.
This is usually an autoimmune process mediated by T-cells and various autoantibodies. As
a result, patients require exogenous insulin to prevent ketoacidosis and maintain glucose
homeostasis.
9. Which of the following describes the ‘Anion Gap’ in the context of acid-base balance?
A. The partial pressure of oxygen in arterial blood.
B. The ratio of bicarbonate to carbonic acid.
C. The amount of carbon dioxide dissolved in the blood.
D. The difference between measured cations and measured anions in serum.
Correct Answer: D
Midterm v3 | Questions with Correct Answers and
Expert Explanation for Each Question |
Chamberlain
1. A patient is diagnosed with cellular atrophy. Which of the following best describes this
process?
A. An increase in the number of cells in an organ.
B. The replacement of one adult cell type by another.
C. A decrease in cell size leading to reduced tissue mass.
D. Abnormal changes in the size, shape, and organization of cells.
Correct Answer: C
Expert Explanation: Cellular atrophy occurs when there is a decrease in cell size, which
often leads to the shrinkage of an entire organ. This process can be physiological, such as
the shrinkage of the thymus during childhood, or pathological due to disuse or ischemia. It
is distinct from hyperplasia, which involves an increase in the number of cells.
2. Which electrolyte imbalance is most likely to cause a widened QRS complex and peaked T
waves on an ECG?
A. Hyperkalemia
B. Hyponatremia
C. Hypokalemia
D. Hypocalcemia
Correct Answer: A
Expert Explanation: Hyperkalemia, or high serum potassium levels, significantly affects
the cardiac resting membrane potential. Peaked T waves and a widened QRS complex are
classic electrocardiogram findings associated with this condition. If left untreated,
hyperkalemia can progress to lethal arrhythmias such as ventricular fibrillation.
3. Which type of hypersensitivity reaction is mediated by IgE antibodies and involves mast
cell degranulation?
A. Type IV Hypersensitivity
B. Type II Hypersensitivity
C. Type III Hypersensitivity
,D. Type I Hypersensitivity
Correct Answer: D
Expert Explanation: Type I hypersensitivity is an immediate allergic reaction triggered
when an allergen binds to IgE antibodies on mast cells. This binding causes the release of
histamine and other inflammatory mediators, leading to symptoms like itching or
anaphylaxis. It is the primary mechanism behind hay fever and asthma.
4. In the Renin-Angiotensin-Aldosterone System (RAAS), what is the primary function of
Angiotensin II?
A. To promote the excretion of sodium in the kidneys.
B. To decrease systemic blood pressure.
C. To inhibit the secretion of Antidiuretic Hormone (ADH).
D. To cause potent vasoconstriction and stimulate aldosterone release.
Correct Answer: D
Expert Explanation: Angiotensin II is a powerful vasoconstrictor that increases systemic
vascular resistance and blood pressure. It also stimulates the adrenal cortex to release
aldosterone, which promotes sodium and water retention. These combined effects are
crucial for maintaining hemodynamic stability during periods of low perfusion.
5. A patient presents with metabolic acidosis. Which compensatory mechanism would the
body likely employ?
A. Hyperventilation to blow off carbon dioxide.
B. Hypoventilation to retain carbon dioxide.
C. Decreased renal excretion of hydrogen ions.
D. Increased renal reabsorption of chloride.
Correct Answer: A
Expert Explanation: Metabolic acidosis involves a decrease in bicarbonate or an increase
in non-volatile acids in the blood. The respiratory system compensates by increasing the
rate and depth of breathing (hyperventilation) to reduce PCO2 levels. This reduction in CO2
helps to return the blood pH toward a normal range.
6. What is the hallmark characteristic of Malignant tumors compared to Benign tumors?
A. Slow growth and well-defined capsules.
B. A lack of vascularity within the tumor mass.
C. Cells that are well-differentiated and resemble parent tissue.
D. The ability to metastasize and invade surrounding tissues.
, Correct Answer: D
Expert Explanation: Malignant tumors are characterized by rapid growth and the ability
to invade local tissues and spread to distant sites. Unlike benign tumors, they lack a fibrous
capsule and often demonstrate anaplasia, meaning the cells are poorly differentiated.
Metastasis is the most definitive sign of malignancy in clinical pathology.
7. Which deficiency is the primary cause of Pernicious Anemia?
A. Iron deficiency
B. Folic acid deficiency
C. Vitamin B12 deficiency due to lack of intrinsic factor
D. Erythropoietin deficiency
Correct Answer: C
Expert Explanation: Pernicious anemia is a type of megaloblastic anemia caused by the
lack of intrinsic factor, which is necessary for Vitamin B12 absorption. Intrinsic factor is
usually produced by the gastric parietal cells, but autoimmune destruction can inhibit its
production. Without Vitamin B12, DNA synthesis in red blood cells is impaired, leading to
large, immature erythrocytes.
8. What is the primary pathophysiology behind Type 1 Diabetes Mellitus?
A. Autoimmune destruction of pancreatic beta cells.
B. Insulin resistance in peripheral tissues.
C. Excessive secretion of glucagon from alpha cells.
D. Increased hepatic glucose production.
Correct Answer: A
Expert Explanation: Type 1 Diabetes Mellitus is characterized by an absolute insulin
deficiency resulting from the destruction of insulin-producing beta cells in the pancreas.
This is usually an autoimmune process mediated by T-cells and various autoantibodies. As
a result, patients require exogenous insulin to prevent ketoacidosis and maintain glucose
homeostasis.
9. Which of the following describes the ‘Anion Gap’ in the context of acid-base balance?
A. The partial pressure of oxygen in arterial blood.
B. The ratio of bicarbonate to carbonic acid.
C. The amount of carbon dioxide dissolved in the blood.
D. The difference between measured cations and measured anions in serum.
Correct Answer: D
