HSC 4555 Final Exam V3 | HSC 4555 Pathophysiology 1 | Actual Q&A
with Rationale (HSC4555 Final Exam) | University of Central Florida
1. A patient exhibits a decrease in muscle size after a limb has been immobilized in a cast for
several weeks. This cellular adaptation is known as:
A. Atrophy
B. Hyperplasia
C. Metaplasia
D. Dysplasia
Answer: A
Explanation: Atrophy is defined as the reduction in the size of cells, which subsequently
leads to a reduction in the size of the organ or tissue. In this clinical scenario, the lack of
mechanical use leads to disuse atrophy of the skeletal muscle. This adaptation allows the
cell to survive under conditions of decreased functional demand by reducing energy
expenditure.
2. Which process involves the programmed and highly regulated death of a cell without
initiating an inflammatory response?
A. Pyoptis
C. Necrosis
B. Autolysis
D. Apoptosis
Answer: D
Explanation: Apoptosis is a physiological or pathological process of cell self-destruction
that is essential for maintaining tissue homeostasis. Unlike necrosis, it is characterized by
nuclear fragmentation and the formation of apoptotic bodies that are phagocytized by
neighboring cells. Because the cell membrane remains intact until phagocytosis, the release
of intracellular contents is prevented, thereby avoiding an inflammatory response.
3. During the acute inflammatory response, what is the primary cause of localized heat and
redness (erythema)?
A. Increased capillary permeability
B. Vasodilation of local blood vessels
C. Leukocyte migration
D. Activation of the clotting cascade
,Answer: B
Explanation: The initial phase of acute inflammation involves the release of chemical
mediators like histamine which cause the relaxation of vascular smooth muscle. This
vasodilation increases blood flow to the injured site, which is clinically manifested as
redness and warmth. These changes are designed to deliver necessary white blood cells
and plasma proteins to the area of injury.
4. A 25-year-old male experiences an immediate allergic reaction after a bee sting,
characterized by respiratory distress and hypotension. This is an example of:
A. Type I Hypersensitivity
B. Type II Hypersensitivity
C. Type III Hypersensitivity
D. Type IV Hypersensitivity
Answer: A
Explanation: Type I hypersensitivity is an IgE-mediated reaction that occurs rapidly after
exposure to an antigen in a previously sensitized individual. The binding of the antigen to
IgE on the surface of mast cells triggers the systemic release of histamine and other
inflammatory mediators. This can lead to anaphylaxis, which involves life-threatening
airway obstruction and vascular collapse.
5. Which compensatory mechanism is primarily responsible for maintaining blood pressure
when there is a decrease in renal perfusion?
A. Inhibition of Antidiuretic Hormone (ADH)
B. Activation of the Renin-Angiotensin-Aldosterone System (RAAS)
C. Release of Atrial Natriuretic Peptide (ANP)
D. Increased parasympathetic nervous system activity
Answer: B
Explanation: When the juxtaglomerular cells in the kidney sense a drop in pressure, they
release the enzyme renin into the bloodstream. Renin facilitates the production of
Angiotensin II, a potent vasoconstrictor that increases systemic vascular resistance.
Additionally, aldosterone is released to promote sodium and water retention, effectively
increasing blood volume and pressure.
6. A patient’s arterial blood gas (ABG) results show pH 7.30, PaCO2 55 mmHg, and HCO3 26
mEq/L. Which acid-base imbalance is present?
A. Metabolic Acidosis
B. Metabolic Alkalosis
, C. Respiratory Acidosis
D. Respiratory Alkalosis
Answer: C
Explanation: Respiratory acidosis is characterized by a decrease in pH (acidemia)
resulting from an increase in PaCO2 (hypercapnia). In this case, the pH is below 7.35 and
the CO2 is significantly elevated, indicating primary respiratory failure in gas exchange.
The normal bicarbonate level suggests that the kidneys have not yet fully compensated for
the chronic or acute retention of carbon dioxide.
7. Hypokalemia is most likely to result in which of the following electrocardiogram (ECG)
changes?
A. Prominent U waves and ST segment depression
B. Shortened QT interval
C. Tall, peaked T waves
D. Widened QRS complex
Answer: A
Explanation: Low serum potassium levels affect the repolarization phase of the cardiac
action potential by altering the resting membrane potential. This typically manifests on an
ECG as the appearance of a U wave following the T wave and a sagging ST segment.
Recognizing these patterns is critical as hypokalemia can predispose patients to lethal
ventricular arrhythmias.
8. A patient with syndrome of inappropriate antidiuretic hormone (SIADH) is at high risk for
which electrolyte abnormality?
A. Hypernatremia
B. Hypercalcemia
C. Hypokalemia
D. Hyponatremia
Answer: D
Explanation: SIADH involves the excessive release of antidiuretic hormone, which leads to
the reabsorption of high volumes of free water in the renal collecting ducts. This excess
water dilutes the extracellular fluid, resulting in a low serum sodium concentration known
as dilutional hyponatremia. The clinical danger lies in the potential for cerebral edema as
water shifts into brain cells due to the osmotic gradient.
9. In the context of neoplasia, what is the primary role of the p53 gene?
A. To act as a tumor suppressor by initiating DNA repair or apoptosis
with Rationale (HSC4555 Final Exam) | University of Central Florida
1. A patient exhibits a decrease in muscle size after a limb has been immobilized in a cast for
several weeks. This cellular adaptation is known as:
A. Atrophy
B. Hyperplasia
C. Metaplasia
D. Dysplasia
Answer: A
Explanation: Atrophy is defined as the reduction in the size of cells, which subsequently
leads to a reduction in the size of the organ or tissue. In this clinical scenario, the lack of
mechanical use leads to disuse atrophy of the skeletal muscle. This adaptation allows the
cell to survive under conditions of decreased functional demand by reducing energy
expenditure.
2. Which process involves the programmed and highly regulated death of a cell without
initiating an inflammatory response?
A. Pyoptis
C. Necrosis
B. Autolysis
D. Apoptosis
Answer: D
Explanation: Apoptosis is a physiological or pathological process of cell self-destruction
that is essential for maintaining tissue homeostasis. Unlike necrosis, it is characterized by
nuclear fragmentation and the formation of apoptotic bodies that are phagocytized by
neighboring cells. Because the cell membrane remains intact until phagocytosis, the release
of intracellular contents is prevented, thereby avoiding an inflammatory response.
3. During the acute inflammatory response, what is the primary cause of localized heat and
redness (erythema)?
A. Increased capillary permeability
B. Vasodilation of local blood vessels
C. Leukocyte migration
D. Activation of the clotting cascade
,Answer: B
Explanation: The initial phase of acute inflammation involves the release of chemical
mediators like histamine which cause the relaxation of vascular smooth muscle. This
vasodilation increases blood flow to the injured site, which is clinically manifested as
redness and warmth. These changes are designed to deliver necessary white blood cells
and plasma proteins to the area of injury.
4. A 25-year-old male experiences an immediate allergic reaction after a bee sting,
characterized by respiratory distress and hypotension. This is an example of:
A. Type I Hypersensitivity
B. Type II Hypersensitivity
C. Type III Hypersensitivity
D. Type IV Hypersensitivity
Answer: A
Explanation: Type I hypersensitivity is an IgE-mediated reaction that occurs rapidly after
exposure to an antigen in a previously sensitized individual. The binding of the antigen to
IgE on the surface of mast cells triggers the systemic release of histamine and other
inflammatory mediators. This can lead to anaphylaxis, which involves life-threatening
airway obstruction and vascular collapse.
5. Which compensatory mechanism is primarily responsible for maintaining blood pressure
when there is a decrease in renal perfusion?
A. Inhibition of Antidiuretic Hormone (ADH)
B. Activation of the Renin-Angiotensin-Aldosterone System (RAAS)
C. Release of Atrial Natriuretic Peptide (ANP)
D. Increased parasympathetic nervous system activity
Answer: B
Explanation: When the juxtaglomerular cells in the kidney sense a drop in pressure, they
release the enzyme renin into the bloodstream. Renin facilitates the production of
Angiotensin II, a potent vasoconstrictor that increases systemic vascular resistance.
Additionally, aldosterone is released to promote sodium and water retention, effectively
increasing blood volume and pressure.
6. A patient’s arterial blood gas (ABG) results show pH 7.30, PaCO2 55 mmHg, and HCO3 26
mEq/L. Which acid-base imbalance is present?
A. Metabolic Acidosis
B. Metabolic Alkalosis
, C. Respiratory Acidosis
D. Respiratory Alkalosis
Answer: C
Explanation: Respiratory acidosis is characterized by a decrease in pH (acidemia)
resulting from an increase in PaCO2 (hypercapnia). In this case, the pH is below 7.35 and
the CO2 is significantly elevated, indicating primary respiratory failure in gas exchange.
The normal bicarbonate level suggests that the kidneys have not yet fully compensated for
the chronic or acute retention of carbon dioxide.
7. Hypokalemia is most likely to result in which of the following electrocardiogram (ECG)
changes?
A. Prominent U waves and ST segment depression
B. Shortened QT interval
C. Tall, peaked T waves
D. Widened QRS complex
Answer: A
Explanation: Low serum potassium levels affect the repolarization phase of the cardiac
action potential by altering the resting membrane potential. This typically manifests on an
ECG as the appearance of a U wave following the T wave and a sagging ST segment.
Recognizing these patterns is critical as hypokalemia can predispose patients to lethal
ventricular arrhythmias.
8. A patient with syndrome of inappropriate antidiuretic hormone (SIADH) is at high risk for
which electrolyte abnormality?
A. Hypernatremia
B. Hypercalcemia
C. Hypokalemia
D. Hyponatremia
Answer: D
Explanation: SIADH involves the excessive release of antidiuretic hormone, which leads to
the reabsorption of high volumes of free water in the renal collecting ducts. This excess
water dilutes the extracellular fluid, resulting in a low serum sodium concentration known
as dilutional hyponatremia. The clinical danger lies in the potential for cerebral edema as
water shifts into brain cells due to the osmotic gradient.
9. In the context of neoplasia, what is the primary role of the p53 gene?
A. To act as a tumor suppressor by initiating DNA repair or apoptosis
