NWCA CET EXAM MASTERY: 120 PRACTICE QUESTIONS WITH CORRECT ANSWERS & CLINICAL RATIONALES

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: A. Depolarization of the ventricles B. Repolarization of the atria C. Depolarization of the atria D. Repolarization of the ventricles CORRECT ANSWER: C. Depolarization of the atria Explanation: The P wave reflects electrical spread through the atria, causing atrial contraction. It is normally upright in leads I, II, and aVF. ________________________________________ 11. The QRS complex represents: A. Depolarization of the atria B. Repolarization of the ventricles C. Depolarization of the ventricles D. AV nodal delay CORRECT ANSWER: C. Depolarization of the ventricles Explanation: The QRS complex represents rapid ventricular depolarization. It is normally narrow (0.06–0.12 sec). Wide QRS indicates a ventricular conduction delay. ________________________________________ 12. The QT interval is measured from: A. Beginning of P wave to end of T wave B. Beginning of QRS complex to end of T wave C. End of QRS to end of T wave D. Beginning of P wave to beginning of QRS CORRECT ANSWER: B. Beginning of QRS complex to end of T wave Explanation: The QT interval represents total ventricular activity