MICN 2026/2027 Study Guide |
Comprehensive Exam Review, High-Yield
Questions & Detailed Answers
Part 1: Foundational Medical Sciences (Q1–Q30)
Q1
What two elements are required for cellular function?
A. Oxygen and glucose
B. Sodium and potassium
C. Water and protein
D. Carbon dioxide and lactate
Correct Answer: A. Oxygen and glucose
Rationale: Cells need oxygen for aerobic metabolism and glucose as an
energy substrate. Without oxygen, cells switch to anaerobic metabolism and
produce lactate.
Q2
What is the dominant intracellular electrolyte?
A. Sodium
B. Potassium
C. Calcium
D. Chloride
Correct Answer: B. Potassium
Rationale: Potassium is the primary intracellular cation, while sodium is
the primary extracellular cation. Potassium abnormalities can cause electrical
instability and arrhythmias.
Q3 (SATA)
Which of the following are functions of sodium? (Select all that apply)
,A. Attracts water for hydration
B. Transmits electrical impulses
C. Buffers excess acid
D. Myocardial and skeletal muscle contraction
Correct Answer: A. Attracts water for hydration
Rationale: Sodium’s primary function is attracting water to maintain
hydration. Potassium transmits electrical impulses, calcium handles muscle
contraction, and bicarbonate buffers acid.
Q4
What is the end product of anaerobic metabolism?
A. Carbonic acid
B. Lactic acid
C. Pyruvic acid
D. Carbon dioxide
Correct Answer: B. Lactic acid
Rationale: Anaerobic metabolism produces lactic acid without oxygen;
aerobic metabolism produces carbonic acid.
Q5
What is the normal stroke volume?
A. 40 mL
B. 60 mL
C. 80 mL
D. 100 mL
Correct Answer: C. 80 mL
Rationale: Normal stroke volume is approximately 80 mL. Cardiac output
= stroke volume × heart rate, normally 5–6 L/min.
Q6
What percentage does the atrial kick contribute to cardiac output?
,A. 10%
B. 20%
C. 30%
D. 40%
Correct Answer: C. 30%
Rationale: The atrial kick pumps extra blood into the ventricles at end-
diastole. Loss of the atrial kick in rapid atrial fibrillation or SVT can reduce stroke
volume and cardiac output by approximately 30%.
Q7
According to Starling’s law, what happens when ventricles are overstretched?
A. Increased contractility
B. Decreased contractility
C. Increased heart rate
D. Increased conduction speed
Correct Answer: B. Decreased contractility
Rationale: Starling’s law states that overstretching myocardial fibers
weakens contractility, like an overstretched rubber band.
Q8
What does “inotropy” define?
A. Heart rate
B. Contractility
C. Conduction speed
D. Diastolic time
Correct Answer: B. Contractility
Rationale: Inotropy refers to contractility; chronotropy refers to heart
rate.
Q9
Preload is primarily determined by what?
, A. Peripheral vascular resistance
B. Venous return
C. Heart rate
D. Myocardial contractility
Correct Answer: B. Venous return
Rationale: Preload is the volume received by the ventricle during diastole
and depends on venous return. The greater the preload (within physiologic
limits), the greater the stroke volume.
Q10
Afterload is primarily determined by what?
A. Venous return
B. Peripheral vascular resistance
C. Heart rate
D. Myocardial contractility
Correct Answer: B. Peripheral vascular resistance
Rationale: Afterload is the resistance the ventricle must overcome to
eject blood, primarily determined by peripheral vascular resistance.
Q11
During which phase of the cardiac cycle does coronary artery perfusion primarily
occur?
A. Systole
B. Diastole
C. Isovolumetric contraction
D. Ejection phase
Correct Answer: B. Diastole
Rationale: Coronary perfusion occurs during diastole when the heart is
not contracting.
Q12
Comprehensive Exam Review, High-Yield
Questions & Detailed Answers
Part 1: Foundational Medical Sciences (Q1–Q30)
Q1
What two elements are required for cellular function?
A. Oxygen and glucose
B. Sodium and potassium
C. Water and protein
D. Carbon dioxide and lactate
Correct Answer: A. Oxygen and glucose
Rationale: Cells need oxygen for aerobic metabolism and glucose as an
energy substrate. Without oxygen, cells switch to anaerobic metabolism and
produce lactate.
Q2
What is the dominant intracellular electrolyte?
A. Sodium
B. Potassium
C. Calcium
D. Chloride
Correct Answer: B. Potassium
Rationale: Potassium is the primary intracellular cation, while sodium is
the primary extracellular cation. Potassium abnormalities can cause electrical
instability and arrhythmias.
Q3 (SATA)
Which of the following are functions of sodium? (Select all that apply)
,A. Attracts water for hydration
B. Transmits electrical impulses
C. Buffers excess acid
D. Myocardial and skeletal muscle contraction
Correct Answer: A. Attracts water for hydration
Rationale: Sodium’s primary function is attracting water to maintain
hydration. Potassium transmits electrical impulses, calcium handles muscle
contraction, and bicarbonate buffers acid.
Q4
What is the end product of anaerobic metabolism?
A. Carbonic acid
B. Lactic acid
C. Pyruvic acid
D. Carbon dioxide
Correct Answer: B. Lactic acid
Rationale: Anaerobic metabolism produces lactic acid without oxygen;
aerobic metabolism produces carbonic acid.
Q5
What is the normal stroke volume?
A. 40 mL
B. 60 mL
C. 80 mL
D. 100 mL
Correct Answer: C. 80 mL
Rationale: Normal stroke volume is approximately 80 mL. Cardiac output
= stroke volume × heart rate, normally 5–6 L/min.
Q6
What percentage does the atrial kick contribute to cardiac output?
,A. 10%
B. 20%
C. 30%
D. 40%
Correct Answer: C. 30%
Rationale: The atrial kick pumps extra blood into the ventricles at end-
diastole. Loss of the atrial kick in rapid atrial fibrillation or SVT can reduce stroke
volume and cardiac output by approximately 30%.
Q7
According to Starling’s law, what happens when ventricles are overstretched?
A. Increased contractility
B. Decreased contractility
C. Increased heart rate
D. Increased conduction speed
Correct Answer: B. Decreased contractility
Rationale: Starling’s law states that overstretching myocardial fibers
weakens contractility, like an overstretched rubber band.
Q8
What does “inotropy” define?
A. Heart rate
B. Contractility
C. Conduction speed
D. Diastolic time
Correct Answer: B. Contractility
Rationale: Inotropy refers to contractility; chronotropy refers to heart
rate.
Q9
Preload is primarily determined by what?
, A. Peripheral vascular resistance
B. Venous return
C. Heart rate
D. Myocardial contractility
Correct Answer: B. Venous return
Rationale: Preload is the volume received by the ventricle during diastole
and depends on venous return. The greater the preload (within physiologic
limits), the greater the stroke volume.
Q10
Afterload is primarily determined by what?
A. Venous return
B. Peripheral vascular resistance
C. Heart rate
D. Myocardial contractility
Correct Answer: B. Peripheral vascular resistance
Rationale: Afterload is the resistance the ventricle must overcome to
eject blood, primarily determined by peripheral vascular resistance.
Q11
During which phase of the cardiac cycle does coronary artery perfusion primarily
occur?
A. Systole
B. Diastole
C. Isovolumetric contraction
D. Ejection phase
Correct Answer: B. Diastole
Rationale: Coronary perfusion occurs during diastole when the heart is
not contracting.
Q12
