HSC 4555 Exam 4 V3 | HSC 4555 Pathophysiology 1 | Actual Q&A with
Rationale (HSC4555 Exam 4) | University of Central Florida
1. A patient presents with a pH of 7.28, a PaCO2 of 55 mmHg, and a HCO3 of 26 mEq/L. Which
condition is most likely occurring?
A. Metabolic Alkalosis
B. Respiratory Alkalosis
C. Metabolic Acidosis
D. Respiratory Acidosis
Answer: D
Explanation: The pH is below the normal range of 7.35, indicating an acidotic state. The
PaCO2 is elevated above 45 mmHg, which points toward a respiratory etiology. Because the
bicarbonate level is still within the normal range, the condition is identified as
uncompensated respiratory acidosis.
2. Which pathological feature is most characteristic of Emphysema?
A. Hypersecretion of mucus in large airways
B. Reversible airway obstruction
C. Permanent dilation of the bronchioles
D. Destruction of alveolar walls without fibrosis
Answer: D
Explanation: Emphysema is characterized by the permanent enlargement of gas-exchange
airways and the destruction of alveolar walls. This leads to a loss of elastic recoil and air
trapping within the lungs. Unlike chronic bronchitis, the primary issue is the loss of surface
area for gas exchange rather than mucus production.
3. What is the primary cause of Pulmonary Edema in patients with left-sided heart failure?
A. Decreased capillary oncotic pressure
B. Increased pulmonary capillary hydrostatic pressure
C. Increased capillary permeability
D. Lymphatic obstruction
Answer: B
,Explanation: Left-sided heart failure causes blood to back up into the pulmonary
circulation. This backup increases the hydrostatic pressure within the pulmonary
capillaries. When this pressure exceeds the oncotic pressure, fluid is pushed into the
interstitial space and alveoli, resulting in edema.
4. A 55-year-old male with a history of smoking presents with a chronic productive cough that
has lasted for 4 months over the past two years. What is the most likely diagnosis?
A. Bronchial Asthma
C. Emphysema
B. Chronic Bronchitis
D. Acute Respiratory Distress Syndrome
Answer: B
Explanation: Chronic bronchitis is clinically defined by a productive cough lasting at least
3 months per year for 2 consecutive years. The pathology involves goblet cell hyperplasia
and thick mucus production. This differs from emphysema, which is defined by structural
changes in the alveoli.
5. Which of the following describes the pathophysiology of Acute Respiratory Distress
Syndrome (ARDS)?
A. Hyperresponsiveness of the airways to allergens
B. Failure of the right ventricle to pump blood to the lungs
C. Chronic collapse of the small airways during expiration
D. Massive inflammatory response causing alveolar-capillary membrane damage
Answer: D
Explanation: ARDS is characterized by widespread inflammation in the lungs and
increased capillary permeability. This results in the formation of hyaline membranes and
non-cardiogenic pulmonary edema. The rapid onset of severe hypoxemia is a hallmark of
this life-threatening condition.
6. In the context of a Tension Pneumothorax, what is the most dangerous physiological
consequence?
A. Infection of the pleural cavity
B. Decreased surfactant production
C. Localized collapse of a single lung lobe
D. Mediastinal shift causing decreased venous return
Answer: D
, Explanation: A tension pneumothorax occurs when air enters the pleural space but cannot
escape, building pressure. This pressure causes a mediastinal shift that compresses the
heart and great vessels. The resulting decrease in venous return can lead to rapid
hemodynamic collapse and death.
7. What is the most common cause of a Pulmonary Embolism?
A. Amniotic fluid during labor
B. Deep vein thrombosis (DVT) in the lower extremities
C. Air bubbles from an IV line
D. Fat globules from a bone fracture
Answer: B
Explanation: Most pulmonary emboli originate from thrombi in the deep veins of the legs.
These clots break loose and travel through the venous system to the right side of the heart
and into the pulmonary arteries. Risk factors include immobility, hypercoagulability, and
endothelial injury.
8. Which mechanism is responsible for the airway obstruction seen in an acute Asthma
attack?
A. Destruction of the alveolar septa
B. Bronchoconstriction and mucosal edema
C. Alveolar collapse due to lack of surfactant
D. Fibrosis of the lung parenchyma
Answer: B
Explanation: Asthma involves a Type I hypersensitivity reaction that leads to mast cell
degranulation. The release of histamine and leukotrienes causes smooth muscle
contraction (bronchospasm) and increased vascular permeability (edema). These factors,
combined with thick mucus, significantly narrow the airways.
9. What is the significance of a ‘Shift to the Left’ in a White Blood Cell differential?
A. An increase in mature lymphocytes
B. A decrease in total leukocyte count
C. An increase in immature neutrophils (bands)
D. An increase in eosinophils during an allergic reaction
Answer: C
Explanation: A shift to the left indicates that the bone marrow is releasing immature
neutrophils, known as bands, into the blood. This typically occurs in response to a severe
Rationale (HSC4555 Exam 4) | University of Central Florida
1. A patient presents with a pH of 7.28, a PaCO2 of 55 mmHg, and a HCO3 of 26 mEq/L. Which
condition is most likely occurring?
A. Metabolic Alkalosis
B. Respiratory Alkalosis
C. Metabolic Acidosis
D. Respiratory Acidosis
Answer: D
Explanation: The pH is below the normal range of 7.35, indicating an acidotic state. The
PaCO2 is elevated above 45 mmHg, which points toward a respiratory etiology. Because the
bicarbonate level is still within the normal range, the condition is identified as
uncompensated respiratory acidosis.
2. Which pathological feature is most characteristic of Emphysema?
A. Hypersecretion of mucus in large airways
B. Reversible airway obstruction
C. Permanent dilation of the bronchioles
D. Destruction of alveolar walls without fibrosis
Answer: D
Explanation: Emphysema is characterized by the permanent enlargement of gas-exchange
airways and the destruction of alveolar walls. This leads to a loss of elastic recoil and air
trapping within the lungs. Unlike chronic bronchitis, the primary issue is the loss of surface
area for gas exchange rather than mucus production.
3. What is the primary cause of Pulmonary Edema in patients with left-sided heart failure?
A. Decreased capillary oncotic pressure
B. Increased pulmonary capillary hydrostatic pressure
C. Increased capillary permeability
D. Lymphatic obstruction
Answer: B
,Explanation: Left-sided heart failure causes blood to back up into the pulmonary
circulation. This backup increases the hydrostatic pressure within the pulmonary
capillaries. When this pressure exceeds the oncotic pressure, fluid is pushed into the
interstitial space and alveoli, resulting in edema.
4. A 55-year-old male with a history of smoking presents with a chronic productive cough that
has lasted for 4 months over the past two years. What is the most likely diagnosis?
A. Bronchial Asthma
C. Emphysema
B. Chronic Bronchitis
D. Acute Respiratory Distress Syndrome
Answer: B
Explanation: Chronic bronchitis is clinically defined by a productive cough lasting at least
3 months per year for 2 consecutive years. The pathology involves goblet cell hyperplasia
and thick mucus production. This differs from emphysema, which is defined by structural
changes in the alveoli.
5. Which of the following describes the pathophysiology of Acute Respiratory Distress
Syndrome (ARDS)?
A. Hyperresponsiveness of the airways to allergens
B. Failure of the right ventricle to pump blood to the lungs
C. Chronic collapse of the small airways during expiration
D. Massive inflammatory response causing alveolar-capillary membrane damage
Answer: D
Explanation: ARDS is characterized by widespread inflammation in the lungs and
increased capillary permeability. This results in the formation of hyaline membranes and
non-cardiogenic pulmonary edema. The rapid onset of severe hypoxemia is a hallmark of
this life-threatening condition.
6. In the context of a Tension Pneumothorax, what is the most dangerous physiological
consequence?
A. Infection of the pleural cavity
B. Decreased surfactant production
C. Localized collapse of a single lung lobe
D. Mediastinal shift causing decreased venous return
Answer: D
, Explanation: A tension pneumothorax occurs when air enters the pleural space but cannot
escape, building pressure. This pressure causes a mediastinal shift that compresses the
heart and great vessels. The resulting decrease in venous return can lead to rapid
hemodynamic collapse and death.
7. What is the most common cause of a Pulmonary Embolism?
A. Amniotic fluid during labor
B. Deep vein thrombosis (DVT) in the lower extremities
C. Air bubbles from an IV line
D. Fat globules from a bone fracture
Answer: B
Explanation: Most pulmonary emboli originate from thrombi in the deep veins of the legs.
These clots break loose and travel through the venous system to the right side of the heart
and into the pulmonary arteries. Risk factors include immobility, hypercoagulability, and
endothelial injury.
8. Which mechanism is responsible for the airway obstruction seen in an acute Asthma
attack?
A. Destruction of the alveolar septa
B. Bronchoconstriction and mucosal edema
C. Alveolar collapse due to lack of surfactant
D. Fibrosis of the lung parenchyma
Answer: B
Explanation: Asthma involves a Type I hypersensitivity reaction that leads to mast cell
degranulation. The release of histamine and leukotrienes causes smooth muscle
contraction (bronchospasm) and increased vascular permeability (edema). These factors,
combined with thick mucus, significantly narrow the airways.
9. What is the significance of a ‘Shift to the Left’ in a White Blood Cell differential?
A. An increase in mature lymphocytes
B. A decrease in total leukocyte count
C. An increase in immature neutrophils (bands)
D. An increase in eosinophils during an allergic reaction
Answer: C
Explanation: A shift to the left indicates that the bone marrow is releasing immature
neutrophils, known as bands, into the blood. This typically occurs in response to a severe
