ANATOMY & PHYSIOLOGY 2 STUDY GUIDE WITH
QUESTIONS AND CORRECT ANSWERS 2026
1. A patient has impaired function of the sinoatrial (SA) node. Which of the
following ECG changes would be expected?
A. Prolonged PR interval
B. Absent P waves with a junctional escape rhythm
C. Wide QRS complexes
D. Prolonged QT interval
Correct Answer: B
Explanation: The SA node normally initiates atrial depolarization (P wave). If it fails,
the AV node or Purkinje fibers may act as a pacemaker, producing a junctional
rhythm without P waves. Prolonged PR interval (A) suggests AV node delay. Wide
QRS (C) indicates ventricular conduction delay. Prolonged QT (D) suggests
ventricular repolarization abnormality.
2. Which hormone directly increases sodium reabsorption in the distal convoluted
tubule and collecting duct?
A. Atrial natriuretic peptide (ANP)
B. Antidiuretic hormone (ADH)
C. Aldosterone
D. Parathyroid hormone (PTH)
Correct Answer: C
Explanation: Aldosterone acts on principal cells of the DCT and collecting duct to
increase Na⁺ reabsorption (and K⁺ excretion). ANP (A) promotes Na⁺ excretion.
ADH (B) primarily increases water reabsorption. PTH (D) increases Ca²⁺
reabsorption in the kidney.
3. A 55-year-old with chronic hypertension presents with shortness of breath and an
S3 gallop. Which phase of the cardiac cycle is most directly affected by the
, increased afterload?
A. Isovolumetric contraction
B. Rapid ventricular ejection
C. Isovolumetric relaxation
D. Rapid ventricular filling
Correct Answer: A
Explanation: Increased afterload (aortic pressure) prolongs isovolumetric
contraction because the left ventricle must generate higher pressure to open the
aortic valve. Ejection (B) is reduced but not the most directly affected phase.
Isovolumetric relaxation (C) and filling (D) are more influenced by preload and
compliance.
4. A patient’s blood gas shows pH 7.25, PaCO₂ 60 mm Hg, HCO₃⁻ 24 mEq/L. What is
the primary acid-base disorder?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct Answer: C
Explanation: Elevated PaCO₂ (>45 mm Hg) with acidic pH indicates respiratory
acidosis. HCO₃⁻ is normal, suggesting no metabolic compensation yet (acute).
Metabolic acidosis (A) would show low HCO₃⁻. Alkalosis (B, D) would have pH
>7.45.
5. Which structure conducts electrical impulses most slowly in the normal heart?
A. SA node
B. Internodal pathways
C. AV node
D. Bundle of His
Correct Answer: C
*Explanation: The AV node has the slowest conduction velocity (0.05–0.1 m/s),
allowing time for ventricular filling. SA node (A) is fast automaticity but not
slowest conduction. Internodal pathways (B) and Bundle of His (D) conduct
rapidly.*
,6. A decrease in plasma albumin concentration would most likely cause:
A. Increased interstitial fluid volume
B. Increased blood colloid osmotic pressure
C. Decreased capillary filtration rate
D. Increased reabsorption at venous end of capillaries
Correct Answer: A
Explanation: Low plasma albumin reduces colloid osmotic pressure, reducing
reabsorption and causing fluid accumulation in interstitial space (edema). Blood
colloid osmotic pressure (B) decreases, not increases. Filtration rate (C) may
increase. Reabsorption (D) decreases.
7. Which of the following is an effect of parasympathetic stimulation on the
respiratory system?
A. Bronchodilation
B. Increased mucus secretion
C. Decreased airway resistance
D. Increased alveolar ventilation
Correct Answer: B
Explanation: Parasympathetic (vagal) stimulation releases ACh on M3 receptors →
bronchoconstriction (not dilation) and increased mucus secretion. Sympathetic (A)
causes bronchodilation. Resistance (C) increases. Ventilation (D) is not directly
increased by parasympathetic tone.
8. A patient has a hematocrit of 60% (normal 42–52%). Which condition is the most
likely cause?
A. Iron deficiency anemia
B. Polycythemia vera
C. Hemophilia A
D. Vitamin B12 deficiency
Correct Answer: B
Explanation: Polycythemia vera causes excessive RBC production → elevated
, hematocrit. Iron deficiency (A) and B12 deficiency (D) cause low hematocrit.
Hemophilia (C) affects coagulation factors, not RBC count.
9. During the T wave of an ECG, what ventricular event is occurring?
A. Rapid depolarization
B. Plateau phase of action potential
C. Repolarization
D. Atrial contraction
Correct Answer: C
Explanation: T wave represents ventricular repolarization. Depolarization (A) is QRS
complex. Plateau (B) is ST segment. Atrial contraction (D) follows P wave.
10. Which blood vessel layer is primarily responsible for vasoconstriction and
vasodilation?
A. Tunica intima
B. Tunica media
C. Tunica externa (adventitia)
D. Basement membrane
Correct Answer: B
Explanation: Tunica media contains smooth muscle and elastic fibers, regulated by
sympathetic nerves and local factors. Intima (A) is endothelium. Externa (C) is
connective tissue. Basement membrane (D) is structural.
11. A 30-year-old with severe diarrhea for 3 days has serum Na⁺ 130 mEq/L, K⁺ 2.8
mEq/L, Cl⁻ 95 mEq/L. Which hormone is likely elevated?
A. Aldosterone
B. ADH
C. ANP
D. Cortisol
Correct Answer: A
Explanation: Diarrhea causes volume depletion and hypokalemia, stimulating
QUESTIONS AND CORRECT ANSWERS 2026
1. A patient has impaired function of the sinoatrial (SA) node. Which of the
following ECG changes would be expected?
A. Prolonged PR interval
B. Absent P waves with a junctional escape rhythm
C. Wide QRS complexes
D. Prolonged QT interval
Correct Answer: B
Explanation: The SA node normally initiates atrial depolarization (P wave). If it fails,
the AV node or Purkinje fibers may act as a pacemaker, producing a junctional
rhythm without P waves. Prolonged PR interval (A) suggests AV node delay. Wide
QRS (C) indicates ventricular conduction delay. Prolonged QT (D) suggests
ventricular repolarization abnormality.
2. Which hormone directly increases sodium reabsorption in the distal convoluted
tubule and collecting duct?
A. Atrial natriuretic peptide (ANP)
B. Antidiuretic hormone (ADH)
C. Aldosterone
D. Parathyroid hormone (PTH)
Correct Answer: C
Explanation: Aldosterone acts on principal cells of the DCT and collecting duct to
increase Na⁺ reabsorption (and K⁺ excretion). ANP (A) promotes Na⁺ excretion.
ADH (B) primarily increases water reabsorption. PTH (D) increases Ca²⁺
reabsorption in the kidney.
3. A 55-year-old with chronic hypertension presents with shortness of breath and an
S3 gallop. Which phase of the cardiac cycle is most directly affected by the
, increased afterload?
A. Isovolumetric contraction
B. Rapid ventricular ejection
C. Isovolumetric relaxation
D. Rapid ventricular filling
Correct Answer: A
Explanation: Increased afterload (aortic pressure) prolongs isovolumetric
contraction because the left ventricle must generate higher pressure to open the
aortic valve. Ejection (B) is reduced but not the most directly affected phase.
Isovolumetric relaxation (C) and filling (D) are more influenced by preload and
compliance.
4. A patient’s blood gas shows pH 7.25, PaCO₂ 60 mm Hg, HCO₃⁻ 24 mEq/L. What is
the primary acid-base disorder?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct Answer: C
Explanation: Elevated PaCO₂ (>45 mm Hg) with acidic pH indicates respiratory
acidosis. HCO₃⁻ is normal, suggesting no metabolic compensation yet (acute).
Metabolic acidosis (A) would show low HCO₃⁻. Alkalosis (B, D) would have pH
>7.45.
5. Which structure conducts electrical impulses most slowly in the normal heart?
A. SA node
B. Internodal pathways
C. AV node
D. Bundle of His
Correct Answer: C
*Explanation: The AV node has the slowest conduction velocity (0.05–0.1 m/s),
allowing time for ventricular filling. SA node (A) is fast automaticity but not
slowest conduction. Internodal pathways (B) and Bundle of His (D) conduct
rapidly.*
,6. A decrease in plasma albumin concentration would most likely cause:
A. Increased interstitial fluid volume
B. Increased blood colloid osmotic pressure
C. Decreased capillary filtration rate
D. Increased reabsorption at venous end of capillaries
Correct Answer: A
Explanation: Low plasma albumin reduces colloid osmotic pressure, reducing
reabsorption and causing fluid accumulation in interstitial space (edema). Blood
colloid osmotic pressure (B) decreases, not increases. Filtration rate (C) may
increase. Reabsorption (D) decreases.
7. Which of the following is an effect of parasympathetic stimulation on the
respiratory system?
A. Bronchodilation
B. Increased mucus secretion
C. Decreased airway resistance
D. Increased alveolar ventilation
Correct Answer: B
Explanation: Parasympathetic (vagal) stimulation releases ACh on M3 receptors →
bronchoconstriction (not dilation) and increased mucus secretion. Sympathetic (A)
causes bronchodilation. Resistance (C) increases. Ventilation (D) is not directly
increased by parasympathetic tone.
8. A patient has a hematocrit of 60% (normal 42–52%). Which condition is the most
likely cause?
A. Iron deficiency anemia
B. Polycythemia vera
C. Hemophilia A
D. Vitamin B12 deficiency
Correct Answer: B
Explanation: Polycythemia vera causes excessive RBC production → elevated
, hematocrit. Iron deficiency (A) and B12 deficiency (D) cause low hematocrit.
Hemophilia (C) affects coagulation factors, not RBC count.
9. During the T wave of an ECG, what ventricular event is occurring?
A. Rapid depolarization
B. Plateau phase of action potential
C. Repolarization
D. Atrial contraction
Correct Answer: C
Explanation: T wave represents ventricular repolarization. Depolarization (A) is QRS
complex. Plateau (B) is ST segment. Atrial contraction (D) follows P wave.
10. Which blood vessel layer is primarily responsible for vasoconstriction and
vasodilation?
A. Tunica intima
B. Tunica media
C. Tunica externa (adventitia)
D. Basement membrane
Correct Answer: B
Explanation: Tunica media contains smooth muscle and elastic fibers, regulated by
sympathetic nerves and local factors. Intima (A) is endothelium. Externa (C) is
connective tissue. Basement membrane (D) is structural.
11. A 30-year-old with severe diarrhea for 3 days has serum Na⁺ 130 mEq/L, K⁺ 2.8
mEq/L, Cl⁻ 95 mEq/L. Which hormone is likely elevated?
A. Aldosterone
B. ADH
C. ANP
D. Cortisol
Correct Answer: A
Explanation: Diarrhea causes volume depletion and hypokalemia, stimulating
