Physiology and Pathophysiology Q&A with
Rationale | Grand Canyon University
1. Which biomarker is most specific for diagnosing a myocardial infarction (MI) due to its
presence in cardiac muscle cells?
A. Creatine Kinase (CK-MB)
B. C-reactive protein (CRP)
C. Myoglobin
D. Troponin I
Answer: D
Rationale: Troponin I is highly specific to cardiac muscle and is released into the
bloodstream when there is damage to the myocardium. Elevated levels are detectable
within a few hours and can remain elevated for several days after an event. This makes it a
superior diagnostic tool compared to CK-MB or myoglobin for identifying acute coronary
syndromes.
2. What is the primary underlying cause of the productive cough and thick mucus seen in
chronic bronchitis?
A. Destruction of alveolar walls
B. Infection by Streptococcus pneumoniae
,C. Dilation of the bronchioles
D. Goblet cell hyperplasia and hypertrophy
Answer: D
Rationale: Chronic bronchitis is characterized by chronic inflammation of the airways
which triggers an increase in the number and size of goblet cells. These cells produce
excessive amounts of thick mucus that the patient attempts to clear through coughing. This
pathological change significantly narrows the airway lumen and impairs ciliary function
over time.
3. A patient is diagnosed with right-sided heart failure. Which clinical manifestation should
the nurse expect to find?
A. Pulmonary edema
B. Dyspnea and orthopnea
C. Peripheral edema and jugular venous distention
D. Crackles in the lungs
Answer: C
Rationale: Right-sided heart failure causes blood to back up into the systemic venous
circulation rather than being pumped effectively to the lungs. This leads to increased
hydrostatic pressure in the systemic veins, resulting in dependent peripheral edema and
enlarged neck veins. Symptoms like pulmonary edema and crackles are typically associated
with left-sided heart failure instead.
, 4. Which mechanism describes the Frank-Starling Law of the heart?
A. Increased heart rate leads to increased cardiac output
B. High afterload decreases the stroke volume
C. Increased stretch of the heart fibers results in increased force of contraction
D. Increased parasympathetic tone slows the AV node conduction
Answer: C
Rationale: The Frank-Starling Law states that the stroke volume of the heart increases in
response to an increase in the volume of blood filling the heart (end-diastolic volume). This
happens because the stretching of the myocardial fibers increases the affinity of troponin
for calcium, leading to a more forceful contraction. Within physiological limits, this ensures
that the heart can match its output to the venous return.
5. In the Renin-Angiotensin-Aldosterone System (RAAS), what is the direct effect of
Angiotensin II on blood vessels?
A. Potent vasoconstriction
B. Release of nitric oxide
C. Systemic vasodilation
D. Decreased peripheral resistance
Answer: A