NWCA CET EXAM MASTERY: 120 PRACTICE
QUESTIONS WITH CORRECT ANSWERS &
CLINICAL RATIONALES
1. Which valves open and allow the ventricles to fill?
A. Aortic and Pulmonic valves
B. Tricuspid and Mitral valves
C. Mitral and Aortic valves
D. Tricuspid and Pulmonic valves
CORRECT ANSWER: B. Tricuspid and Mitral valves
Explanation: During diastole, the atrioventricular valves (tricuspid on
the right, mitral on the left) open to allow blood to flow from the atria
into the ventricles.
2. The layer of the heart that is damaged during a heart attack is the:
A. Epicardium
B. Pericardium
C. Myocardium
D. Endocardium
,CORRECT ANSWER: C. Myocardium
Explanation: The myocardium is the muscular middle layer of the heart.
Myocardial infarction (heart attack) involves death of myocardial tissue
due to lack of oxygen.
3. The inferior vena cava returns oxygen-depleted blood to the heart
from the:
A. Upper part of the body
B. Lungs
C. Lower part of the body
D. Coronary arteries
CORRECT ANSWER: C. Lower part of the body
Explanation: The inferior vena cava carries deoxygenated blood from
the lower extremities, abdomen, and pelvis back to the right atrium.
4. The pulmonary veins deliver blood to the:
A. Right atria
B. Left atria
C. Right ventricle
D. Left ventricle
CORRECT ANSWER: B. Left atria
Explanation: The four pulmonary veins carry oxygenated blood from the
lungs to the left atrium, which then pumps it into the left ventricle.
5. The ventricles' intrinsic firing rate is between:
,A. 60 and 100 bpm
B. 40 and 60 bpm
C. 20 and 40 bpm
D. 0 and 20 bpm
CORRECT ANSWER: C. 20 and 40 bpm
Explanation: The ventricles have an intrinsic escape rhythm of 20–40
bpm if higher pacemakers (SA node, atria, AV node) fail.
6. The cardiac cycle's two phases are:
A. Systole and repolarization
B. Diastole and depolarization
C. Systole and diastole
D. Contraction and relaxation
CORRECT ANSWER: C. Systole and diastole
Explanation: Systole is contraction/ejection; diastole is relaxation/filling.
Together they form one complete cardiac cycle.
7. Depolarization is best defined as:
A. Cell becomes more negative and relaxes
B. Cell becomes less negative and contracts
C. Cell returns to resting potential
D. Cell stops conducting electricity
CORRECT ANSWER: B. Cell becomes less negative and contracts
Explanation: Depolarization occurs when sodium ions enter the cell,
, making the membrane potential less negative (toward positive),
triggering contraction.
8. Which criteria represent a patient in normal sinus rhythm?
A. Rate 40-60, irregular intervals
B. Rate 60-100, equal R-R intervals
C. Rate 100-150, variable P waves
D. Rate 20-40, wide QRS
CORRECT ANSWER: B. Rate 60-100, equal R-R intervals
*Explanation: Normal sinus rhythm requires a rate of 60–100 bpm,
regular R-R intervals, one P wave before each QRS, and normal PR/QRS
intervals.*
9. Each large box (five small boxes) on an ECG strip is equal to:
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.50 seconds
CORRECT ANSWER: C. 0.20 seconds
*Explanation: At standard paper speed (25 mm/s), each small box =
0.04 sec, each large box (5 small boxes) = 0.20 sec.*
10. The P wave represents:
QUESTIONS WITH CORRECT ANSWERS &
CLINICAL RATIONALES
1. Which valves open and allow the ventricles to fill?
A. Aortic and Pulmonic valves
B. Tricuspid and Mitral valves
C. Mitral and Aortic valves
D. Tricuspid and Pulmonic valves
CORRECT ANSWER: B. Tricuspid and Mitral valves
Explanation: During diastole, the atrioventricular valves (tricuspid on
the right, mitral on the left) open to allow blood to flow from the atria
into the ventricles.
2. The layer of the heart that is damaged during a heart attack is the:
A. Epicardium
B. Pericardium
C. Myocardium
D. Endocardium
,CORRECT ANSWER: C. Myocardium
Explanation: The myocardium is the muscular middle layer of the heart.
Myocardial infarction (heart attack) involves death of myocardial tissue
due to lack of oxygen.
3. The inferior vena cava returns oxygen-depleted blood to the heart
from the:
A. Upper part of the body
B. Lungs
C. Lower part of the body
D. Coronary arteries
CORRECT ANSWER: C. Lower part of the body
Explanation: The inferior vena cava carries deoxygenated blood from
the lower extremities, abdomen, and pelvis back to the right atrium.
4. The pulmonary veins deliver blood to the:
A. Right atria
B. Left atria
C. Right ventricle
D. Left ventricle
CORRECT ANSWER: B. Left atria
Explanation: The four pulmonary veins carry oxygenated blood from the
lungs to the left atrium, which then pumps it into the left ventricle.
5. The ventricles' intrinsic firing rate is between:
,A. 60 and 100 bpm
B. 40 and 60 bpm
C. 20 and 40 bpm
D. 0 and 20 bpm
CORRECT ANSWER: C. 20 and 40 bpm
Explanation: The ventricles have an intrinsic escape rhythm of 20–40
bpm if higher pacemakers (SA node, atria, AV node) fail.
6. The cardiac cycle's two phases are:
A. Systole and repolarization
B. Diastole and depolarization
C. Systole and diastole
D. Contraction and relaxation
CORRECT ANSWER: C. Systole and diastole
Explanation: Systole is contraction/ejection; diastole is relaxation/filling.
Together they form one complete cardiac cycle.
7. Depolarization is best defined as:
A. Cell becomes more negative and relaxes
B. Cell becomes less negative and contracts
C. Cell returns to resting potential
D. Cell stops conducting electricity
CORRECT ANSWER: B. Cell becomes less negative and contracts
Explanation: Depolarization occurs when sodium ions enter the cell,
, making the membrane potential less negative (toward positive),
triggering contraction.
8. Which criteria represent a patient in normal sinus rhythm?
A. Rate 40-60, irregular intervals
B. Rate 60-100, equal R-R intervals
C. Rate 100-150, variable P waves
D. Rate 20-40, wide QRS
CORRECT ANSWER: B. Rate 60-100, equal R-R intervals
*Explanation: Normal sinus rhythm requires a rate of 60–100 bpm,
regular R-R intervals, one P wave before each QRS, and normal PR/QRS
intervals.*
9. Each large box (five small boxes) on an ECG strip is equal to:
A. 0.04 seconds
B. 0.10 seconds
C. 0.20 seconds
D. 0.50 seconds
CORRECT ANSWER: C. 0.20 seconds
*Explanation: At standard paper speed (25 mm/s), each small box =
0.04 sec, each large box (5 small boxes) = 0.20 sec.*
10. The P wave represents:
