HSC 4555 Exam 2 V1 | HSC 4555 Pathophysiology 1 | Actual Q&A with
Rationale (HSC4555 Exam 2) | University of Central Florida
1. A patient presents with a serum sodium level of 155 mEq/L. Which clinical manifestation is
most likely to be observed in this individual?
A. Thirst and dry mucous membranes
B. Confusion and lethargy
C. Muscle weakness and paralysis
D. Hyperactive deep tendon reflexes
Answer: A
Explanation: Hypernatremia, defined as a serum sodium level above 145 mEq/L, primarily
results in cellular dehydration as water is drawn out of cells. Thirst is the body’s primary
defense mechanism against increased osmolarity, and dry mucous membranes are a
hallmark physical finding. This condition requires careful management to prevent rapid
fluid shifts that could lead to cerebral edema during correction.
2. Which of the following acid-base imbalances is most commonly associated with chronic
obstructive pulmonary disease (COPD)?
A. Metabolic Acidosis
B. Metabolic Alkalosis
C. Respiratory Acidosis
D. Respiratory Alkalosis
Answer: C
Explanation: Respiratory acidosis occurs when there is alveolar hypoventilation, leading
to the retention of carbon dioxide (hypercapnia). In chronic conditions like COPD, the lungs
cannot effectively exhale CO2, resulting in a decrease in systemic pH. The kidneys
eventually attempt to compensate by retaining bicarbonate, but the primary insult remains
respiratory in nature.
3. In the process of inflammation, which chemical mediator is primarily responsible for
inducing pain by sensitizing nociceptors?
A. Histamine
B. Prostaglandins
C. Leukotrienes
D. Cytokines
,Answer: B
Explanation: Prostaglandins are produced via the cyclooxygenase pathway and play a
critical role in the inflammatory response by inducing vasodilation and fever. Crucially,
they sensitize pain receptors to other inflammatory mediators like bradykinin, which
translates to the clinical sensation of pain. This mechanism is why NSAIDs, which inhibit
prostaglandin synthesis, are effective for pain management.
4. A patient is diagnosed with an Arthus reaction after receiving a booster injection. This is an
example of which type of hypersensitivity?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: C
Explanation: Type III hypersensitivity involves the formation of antigen-antibody
complexes that deposit in tissues, leading to complement activation and neutrophil
recruitment. The Arthus reaction is a localized type III response that occurs after repeat
exposure to an antigen, resulting in localized vasculitis and tissue necrosis. Unlike type I,
this process is mediated by IgG or IgM rather than IgE.
5. During cellular injury, the depletion of ATP leads to the failure of the Na+/K+ pump. What
is the immediate consequence of this failure?
A. Intracellular swelling
B. Cellular shrinkage
C. Decreased osmotic pressure
D. Increased protein synthesis
Answer: A
Explanation: The failure of the sodium-potassium pump allows sodium to accumulate
inside the cell, which creates an osmotic gradient that draws water inward. This process
leads to acute cellular swelling, also known as hydropic degeneration, which is a reversible
stage of cell injury. If ATP production is not restored, the increased pressure can lead to the
rupture of organelles and the plasma membrane.
6. Which characteristic is most indicative of a malignant tumor rather than a benign one?
A. Slow growth rate
B. Presence of metastasis
C. Well-differentiated cells
, D. Presence of a fibrous capsule
Answer: B
Explanation: Metastasis, the spread of cancer cells to distant sites, is the most definitive
characteristic of malignancy. Unlike benign tumors, malignant cells possess the ability to
invade surrounding tissues and enter the lymphatic or circulatory systems. Additionally,
malignant tumors often show anaplasia, meaning they lose the specialized features of their
parent tissue.
7. A 55-year-old male presents with persistent chest pain. An EKG shows ST-segment
elevation. Which biochemical marker is most specific for myocardial infarction?
A. Creatine Kinase (CK-MB)
B. Troponin I
C. Lactate Dehydrogenase (LDH)
D. Myoglobin
Answer: B
Explanation: Troponin I and T are highly specific structural proteins found in cardiac
muscle that are released into the bloodstream following myocardial injury. They are
preferred over CK-MB because they stay elevated for a longer period and have higher
sensitivity for cardiac damage. Prompt identification of these markers is essential for
initiating reperfusion therapy in acute coronary syndromes.
8. Which type of necrosis is most commonly associated with ischemic injury to the brain?
A. Coagulative necrosis
B. Caseous necrosis
C. Liquefactive necrosis
D. Fat necrosis
Answer: C
Explanation: Liquefactive necrosis occurs in the brain because the tissue is rich in lipids
and hydrolytic enzymes, but poor in connective tissue. When brain cells die, these enzymes
digest the tissue into a liquid mass, often resulting in the formation of a cyst or abscess. In
contrast, coagulative necrosis is more common in solid organs like the heart or kidneys.
9. Which electrolyte imbalance is a frequent complication of metabolic acidosis as the body
attempts to buffer excess hydrogen ions?
A. Hypocalcemia
B. Hypomagnesemia
Rationale (HSC4555 Exam 2) | University of Central Florida
1. A patient presents with a serum sodium level of 155 mEq/L. Which clinical manifestation is
most likely to be observed in this individual?
A. Thirst and dry mucous membranes
B. Confusion and lethargy
C. Muscle weakness and paralysis
D. Hyperactive deep tendon reflexes
Answer: A
Explanation: Hypernatremia, defined as a serum sodium level above 145 mEq/L, primarily
results in cellular dehydration as water is drawn out of cells. Thirst is the body’s primary
defense mechanism against increased osmolarity, and dry mucous membranes are a
hallmark physical finding. This condition requires careful management to prevent rapid
fluid shifts that could lead to cerebral edema during correction.
2. Which of the following acid-base imbalances is most commonly associated with chronic
obstructive pulmonary disease (COPD)?
A. Metabolic Acidosis
B. Metabolic Alkalosis
C. Respiratory Acidosis
D. Respiratory Alkalosis
Answer: C
Explanation: Respiratory acidosis occurs when there is alveolar hypoventilation, leading
to the retention of carbon dioxide (hypercapnia). In chronic conditions like COPD, the lungs
cannot effectively exhale CO2, resulting in a decrease in systemic pH. The kidneys
eventually attempt to compensate by retaining bicarbonate, but the primary insult remains
respiratory in nature.
3. In the process of inflammation, which chemical mediator is primarily responsible for
inducing pain by sensitizing nociceptors?
A. Histamine
B. Prostaglandins
C. Leukotrienes
D. Cytokines
,Answer: B
Explanation: Prostaglandins are produced via the cyclooxygenase pathway and play a
critical role in the inflammatory response by inducing vasodilation and fever. Crucially,
they sensitize pain receptors to other inflammatory mediators like bradykinin, which
translates to the clinical sensation of pain. This mechanism is why NSAIDs, which inhibit
prostaglandin synthesis, are effective for pain management.
4. A patient is diagnosed with an Arthus reaction after receiving a booster injection. This is an
example of which type of hypersensitivity?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: C
Explanation: Type III hypersensitivity involves the formation of antigen-antibody
complexes that deposit in tissues, leading to complement activation and neutrophil
recruitment. The Arthus reaction is a localized type III response that occurs after repeat
exposure to an antigen, resulting in localized vasculitis and tissue necrosis. Unlike type I,
this process is mediated by IgG or IgM rather than IgE.
5. During cellular injury, the depletion of ATP leads to the failure of the Na+/K+ pump. What
is the immediate consequence of this failure?
A. Intracellular swelling
B. Cellular shrinkage
C. Decreased osmotic pressure
D. Increased protein synthesis
Answer: A
Explanation: The failure of the sodium-potassium pump allows sodium to accumulate
inside the cell, which creates an osmotic gradient that draws water inward. This process
leads to acute cellular swelling, also known as hydropic degeneration, which is a reversible
stage of cell injury. If ATP production is not restored, the increased pressure can lead to the
rupture of organelles and the plasma membrane.
6. Which characteristic is most indicative of a malignant tumor rather than a benign one?
A. Slow growth rate
B. Presence of metastasis
C. Well-differentiated cells
, D. Presence of a fibrous capsule
Answer: B
Explanation: Metastasis, the spread of cancer cells to distant sites, is the most definitive
characteristic of malignancy. Unlike benign tumors, malignant cells possess the ability to
invade surrounding tissues and enter the lymphatic or circulatory systems. Additionally,
malignant tumors often show anaplasia, meaning they lose the specialized features of their
parent tissue.
7. A 55-year-old male presents with persistent chest pain. An EKG shows ST-segment
elevation. Which biochemical marker is most specific for myocardial infarction?
A. Creatine Kinase (CK-MB)
B. Troponin I
C. Lactate Dehydrogenase (LDH)
D. Myoglobin
Answer: B
Explanation: Troponin I and T are highly specific structural proteins found in cardiac
muscle that are released into the bloodstream following myocardial injury. They are
preferred over CK-MB because they stay elevated for a longer period and have higher
sensitivity for cardiac damage. Prompt identification of these markers is essential for
initiating reperfusion therapy in acute coronary syndromes.
8. Which type of necrosis is most commonly associated with ischemic injury to the brain?
A. Coagulative necrosis
B. Caseous necrosis
C. Liquefactive necrosis
D. Fat necrosis
Answer: C
Explanation: Liquefactive necrosis occurs in the brain because the tissue is rich in lipids
and hydrolytic enzymes, but poor in connective tissue. When brain cells die, these enzymes
digest the tissue into a liquid mass, often resulting in the formation of a cyst or abscess. In
contrast, coagulative necrosis is more common in solid organs like the heart or kidneys.
9. Which electrolyte imbalance is a frequent complication of metabolic acidosis as the body
attempts to buffer excess hydrogen ions?
A. Hypocalcemia
B. Hypomagnesemia
