PARAMEDIC CARDIOLOGY ULTIMATE EXAM
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SECTION 1: CARDIAC ANATOMY & PHYSIOLOGY
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1. Which structure initiates the electrical impulse in the normal adult heart?
A) AV node
B) Bundle of His
C) SA node
D) Purkinje fibers
Answer: C
Explanation: The sinoatrial (SA) node, located in the right atrial wall, is the primary
pacemaker that generates the impulse for each cardiac cycle. It normally fires at a rate of
60–100 beats per minute.
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2. What is the normal intrinsic firing rate of the atrioventricular (AV) node?
A) 20–40 BPM
B) 40–60 BPM
C) 60–100 BPM
D) 100–150 BPM
Answer: B
Explanation: The AV node has an intrinsic firing rate of 40–60 BPM.
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3. What is the normal intrinsic firing rate of the Purkinje fibers?
A) 20–40 BPM
B) 40–60 BPM
C) 60–100 BPM
D) 100–150 BPM
Answer: A
Explanation: The Purkinje fibers have the slowest intrinsic rate of 20–40 BPM.
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4. The Frank-Starling law describes the relationship between:
A) Afterload and heart rate
B) Preload and stroke volume
C) Contractility and ejection fraction
D) Heart rate and cardiac output
Answer: B
Explanation: Increased preload (ventricular end-diastolic volume) leads to greater
sarcomere stretch, enhancing stroke volume up to a physiological limit.
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,5. Which phase of the ventricular action potential corresponds to the rapid depolarization
caused by Na⁺ influx?
A) Phase 0
B) Phase 1
C) Phase 2
D) Phase 3
Answer: A
Explanation: Phase 0 is the upstroke of the action potential where fast Na⁺ channels open,
producing a rapid rise in membrane voltage.
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6. During which phase of the cardiac action potential does the plateau phase occur,
primarily due to Ca²⁺ influx?
A) Phase 0
B) Phase 1
C) Phase 2
D) Phase 3
Answer: C
Explanation: Phase 2 is the plateau phase, maintained by the influx of calcium ions
through slow calcium channels, which balances potassium efflux.
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7. Which of the following valves prevents backflow of blood from the left ventricle into the
left atrium?
, A) Aortic valve
B) Pulmonary valve
C) Mitral valve
D) Tricuspid valve
Answer: C
Explanation: The mitral (bicuspid) valve is located between the left atrium and the left
ventricle and prevents backflow of blood into the left atrium during ventricular systole.
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8. The tricuspid valve is located between which two structures?
A) Left atrium and left ventricle
B) Right atrium and right ventricle
C) Right ventricle and pulmonary artery
D) Left ventricle and aorta
Answer: B
Explanation: The tricuspid valve is between the right atrium and the right ventricle.
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9. Which of the following correctly describes the pathway of blood through the heart?
A) Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary
artery → lungs → pulmonary veins → left atrium → mitral valve → left ventricle → aortic
valve → aorta
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SECTION 1: CARDIAC ANATOMY & PHYSIOLOGY
---
1. Which structure initiates the electrical impulse in the normal adult heart?
A) AV node
B) Bundle of His
C) SA node
D) Purkinje fibers
Answer: C
Explanation: The sinoatrial (SA) node, located in the right atrial wall, is the primary
pacemaker that generates the impulse for each cardiac cycle. It normally fires at a rate of
60–100 beats per minute.
---
2. What is the normal intrinsic firing rate of the atrioventricular (AV) node?
A) 20–40 BPM
B) 40–60 BPM
C) 60–100 BPM
D) 100–150 BPM
Answer: B
Explanation: The AV node has an intrinsic firing rate of 40–60 BPM.
,---
3. What is the normal intrinsic firing rate of the Purkinje fibers?
A) 20–40 BPM
B) 40–60 BPM
C) 60–100 BPM
D) 100–150 BPM
Answer: A
Explanation: The Purkinje fibers have the slowest intrinsic rate of 20–40 BPM.
---
4. The Frank-Starling law describes the relationship between:
A) Afterload and heart rate
B) Preload and stroke volume
C) Contractility and ejection fraction
D) Heart rate and cardiac output
Answer: B
Explanation: Increased preload (ventricular end-diastolic volume) leads to greater
sarcomere stretch, enhancing stroke volume up to a physiological limit.
---
,5. Which phase of the ventricular action potential corresponds to the rapid depolarization
caused by Na⁺ influx?
A) Phase 0
B) Phase 1
C) Phase 2
D) Phase 3
Answer: A
Explanation: Phase 0 is the upstroke of the action potential where fast Na⁺ channels open,
producing a rapid rise in membrane voltage.
---
6. During which phase of the cardiac action potential does the plateau phase occur,
primarily due to Ca²⁺ influx?
A) Phase 0
B) Phase 1
C) Phase 2
D) Phase 3
Answer: C
Explanation: Phase 2 is the plateau phase, maintained by the influx of calcium ions
through slow calcium channels, which balances potassium efflux.
---
7. Which of the following valves prevents backflow of blood from the left ventricle into the
left atrium?
, A) Aortic valve
B) Pulmonary valve
C) Mitral valve
D) Tricuspid valve
Answer: C
Explanation: The mitral (bicuspid) valve is located between the left atrium and the left
ventricle and prevents backflow of blood into the left atrium during ventricular systole.
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8. The tricuspid valve is located between which two structures?
A) Left atrium and left ventricle
B) Right atrium and right ventricle
C) Right ventricle and pulmonary artery
D) Left ventricle and aorta
Answer: B
Explanation: The tricuspid valve is between the right atrium and the right ventricle.
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9. Which of the following correctly describes the pathway of blood through the heart?
A) Right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary
artery → lungs → pulmonary veins → left atrium → mitral valve → left ventricle → aortic
valve → aorta
