NR 661 COMPREHENSIVE EXAMINATION TEST
2026 QUESTIONS WITH SOLUTIONS
▶ Define Conductivity. Answer: The ability to receive and transmit
electrical impulses to adjacent cells.
▶ Define Contractility. Answer: A myocardial cell's ability to shorten (or
contract) in response to a stimulus.
▶ Define Depolarization. Answer: Occurs when positively charged ions
(such as sodium and calcium) rapidly move from outside the myocardial
cell membrane to the inside, changing the overall charge from negative to a
positive.
▶ Define Repolarization. Answer: Occurs immediately after depolarization
and is the movement of positively charged ions back to the outside of the
cell, returning the cell back to its original polarized state. A cell must
repolarize before it can depolarize again.
▶ Absolute Refractory Period. Answer: Is the 1st phase of repolarization in
which a myocardial cell is unable to react to any electrical stimulus.
▶ Relative Refractory Period. Answer: Is the 2nd phase of repolarization
during which time a strong enough electrical stimulus might cause new
depolarization and contraction.
▶ Conduction System of The Heart. Answer: Generates and delivers
(conducts) the electricity to all the muscle fibers of the heart resulting in a
smooth, complete contraction of the cardiac muscle fibers, which forcefully
ejects the blood outside the heart.
▶ SA Node. Answer: Found in the upper posterior portion of the right atrial
wall just below the opening of the superior vena cava. It is the primary
pacemaker of the heart and has a normal firing rate of 60-100 bpm.
▶ Define Internodal Pathways. Answer: Consists of anterior, middle and
posterior division that distribute electrical impulses generated by the SA
node throughout the right and left atria to the atrio-ventricular (AV) node.
,▶ Define AV Junction (AV node). Answer: This node is located at the
posterior septal wall of the right atrium just above the tricuspid valve. There
is normally a .12-.20 second delay of electrical activity at this level to allow
blood to flow from the atria and fill the ventricles with blood.
▶ Bundle of His. Answer: Found at the superior portion of the
interventricular septum, it is the pathway that leads out of the AV node and
connects to the Bundle Branches.
▶ Bundle Branches. Answer: Located at the interventricular septum, the
Bundle His divides into the right and left bundle branches, the function of
which is to conduct the electrical impulse to the Purkinje fibers throughout
the ventricles,
▶ Purkinje Fibers. Answer: Found within the ventricular endocardium, it
consists of a network of small conduction fibers that deliver the electrical
impulses from the Bundle Branches to the ventricular myocardium.
▶ EKG is a _____ that measures the heart electricity traveling through the
conductive system and an important tool for patient's diagnosis.. Answer:
Galvanometer
▶ EKG Evaluation:. Answer: -Monitoring patient's HR
-Evaluates injuries to the heart muscle
-Evaluates the pacemakers and conductive system function
-Evaluate the response toward medication
-Provides a baseline record for medical procedure
▶ Define Electrode. Answer: Is a paper, plastic or metal sensor placed on
the patient's skin on a specific location and transmit it to the cable.
▶ Define Cable. Answer: Is a wire that connects the electrode to the EKG
machine (cardiac monitor).
▶ Define Lead. Answer: Is a recorded tracing of the heart electricity from
one or two electrodes that provides a specific view of the heart.
▶ Standard Bipolar Limb Leads. Answer: Record electrical activity in the
frontal plane. Electrodes are applied to the left arm (LA), the right arm (RA)
,and the left leg (LL). These leads record the difference in electricity
between two electrode.
▶ Lead I. Answer: The left arm is positive and the right arm is negative.
(LA-RA)
▶ Lead II. Answer: The left leg is positive and the right arm is negative.
(LL-RA)
▶ Lead III. Answer: The left leg is positive and the left are is negative. (LL-
LA)
▶ Define Augmented Unipolar. Answer: Also records electrical activity in
the frontal plane.
▶ Define Augmented Unipolar Leads. Answer: Record the heart electricity
from one limb and compare it with a zero voltage lead in the center of the
heart.
▶ AV stands for. Answer: Augmented Coltage
▶ R stands for. Answer: Right Arm (RA)
▶ L stands for. Answer: Left Arm (LA)
▶ F stands for. Answer: Left Leg (LL)
▶ Lead aVR. Answer: The right arm is positive and the other limbs are
negative.
▶ Lead aVL. Answer: The left arm is positive and the other limbs are
negative.
▶ Lead aVF. Answer: The left leg (or foot) is positive and the other limbs
are negative.
▶ Precordial Chest Unipolar Leads. Answer: All these electrodes are
positive and record the heart electricity in the horizontal plane. They include
leads: V1, V2, V3, V4, V5, and V6.
, ▶ V1. Answer: Fourth intercostal space, right sternal border.
▶ V2. Answer: Fourth intercostal space, left sternal border.
▶ V3. Answer: Equidistant between V2 and V4.
▶ V4. Answer: Fifth intercostal space, left midclavicular line.
▶ V5. Answer: Fifth intercostal space, anterior axillary line.
▶ V6. Answer: Fifth intercostal space, midaxillary line.
▶ The Electrocardiographic Grid and Waves. Answer: The EKG paper is a
graph paper with horizontal and vertical lines at 1-mm intervals. A heavy
line appears every 5mm.
▶ The horizontal axis represents time:. Answer: 1mm = 0.04 seconds
5mm = 0.2 seconds
▶ The vertical axis represents:. Answer: voltage, measures in millivolts
(1/1000 part of a volt) but expressed in millimeters: 0.1mV-1mm.
▶ The tracing is marked on the paper by a stylus using _____.. Answer:
heat
▶ The running speed of an EKG machine is _____.. Answer: 25mm/sec
▶ The EKG machine must be properly standardized so that 1mV will
produce a deflection of _____.. Answer: 10mm
▶ Define Waveform. Answer: Refers to movement away from the
isoelectric line either upward (positive) deflection or downward (negative)
deflection.
▶ Define Segment. Answer: Line between two waveforms.
▶ Define Interval. Answer: Waveform plus a segment.
2026 QUESTIONS WITH SOLUTIONS
▶ Define Conductivity. Answer: The ability to receive and transmit
electrical impulses to adjacent cells.
▶ Define Contractility. Answer: A myocardial cell's ability to shorten (or
contract) in response to a stimulus.
▶ Define Depolarization. Answer: Occurs when positively charged ions
(such as sodium and calcium) rapidly move from outside the myocardial
cell membrane to the inside, changing the overall charge from negative to a
positive.
▶ Define Repolarization. Answer: Occurs immediately after depolarization
and is the movement of positively charged ions back to the outside of the
cell, returning the cell back to its original polarized state. A cell must
repolarize before it can depolarize again.
▶ Absolute Refractory Period. Answer: Is the 1st phase of repolarization in
which a myocardial cell is unable to react to any electrical stimulus.
▶ Relative Refractory Period. Answer: Is the 2nd phase of repolarization
during which time a strong enough electrical stimulus might cause new
depolarization and contraction.
▶ Conduction System of The Heart. Answer: Generates and delivers
(conducts) the electricity to all the muscle fibers of the heart resulting in a
smooth, complete contraction of the cardiac muscle fibers, which forcefully
ejects the blood outside the heart.
▶ SA Node. Answer: Found in the upper posterior portion of the right atrial
wall just below the opening of the superior vena cava. It is the primary
pacemaker of the heart and has a normal firing rate of 60-100 bpm.
▶ Define Internodal Pathways. Answer: Consists of anterior, middle and
posterior division that distribute electrical impulses generated by the SA
node throughout the right and left atria to the atrio-ventricular (AV) node.
,▶ Define AV Junction (AV node). Answer: This node is located at the
posterior septal wall of the right atrium just above the tricuspid valve. There
is normally a .12-.20 second delay of electrical activity at this level to allow
blood to flow from the atria and fill the ventricles with blood.
▶ Bundle of His. Answer: Found at the superior portion of the
interventricular septum, it is the pathway that leads out of the AV node and
connects to the Bundle Branches.
▶ Bundle Branches. Answer: Located at the interventricular septum, the
Bundle His divides into the right and left bundle branches, the function of
which is to conduct the electrical impulse to the Purkinje fibers throughout
the ventricles,
▶ Purkinje Fibers. Answer: Found within the ventricular endocardium, it
consists of a network of small conduction fibers that deliver the electrical
impulses from the Bundle Branches to the ventricular myocardium.
▶ EKG is a _____ that measures the heart electricity traveling through the
conductive system and an important tool for patient's diagnosis.. Answer:
Galvanometer
▶ EKG Evaluation:. Answer: -Monitoring patient's HR
-Evaluates injuries to the heart muscle
-Evaluates the pacemakers and conductive system function
-Evaluate the response toward medication
-Provides a baseline record for medical procedure
▶ Define Electrode. Answer: Is a paper, plastic or metal sensor placed on
the patient's skin on a specific location and transmit it to the cable.
▶ Define Cable. Answer: Is a wire that connects the electrode to the EKG
machine (cardiac monitor).
▶ Define Lead. Answer: Is a recorded tracing of the heart electricity from
one or two electrodes that provides a specific view of the heart.
▶ Standard Bipolar Limb Leads. Answer: Record electrical activity in the
frontal plane. Electrodes are applied to the left arm (LA), the right arm (RA)
,and the left leg (LL). These leads record the difference in electricity
between two electrode.
▶ Lead I. Answer: The left arm is positive and the right arm is negative.
(LA-RA)
▶ Lead II. Answer: The left leg is positive and the right arm is negative.
(LL-RA)
▶ Lead III. Answer: The left leg is positive and the left are is negative. (LL-
LA)
▶ Define Augmented Unipolar. Answer: Also records electrical activity in
the frontal plane.
▶ Define Augmented Unipolar Leads. Answer: Record the heart electricity
from one limb and compare it with a zero voltage lead in the center of the
heart.
▶ AV stands for. Answer: Augmented Coltage
▶ R stands for. Answer: Right Arm (RA)
▶ L stands for. Answer: Left Arm (LA)
▶ F stands for. Answer: Left Leg (LL)
▶ Lead aVR. Answer: The right arm is positive and the other limbs are
negative.
▶ Lead aVL. Answer: The left arm is positive and the other limbs are
negative.
▶ Lead aVF. Answer: The left leg (or foot) is positive and the other limbs
are negative.
▶ Precordial Chest Unipolar Leads. Answer: All these electrodes are
positive and record the heart electricity in the horizontal plane. They include
leads: V1, V2, V3, V4, V5, and V6.
, ▶ V1. Answer: Fourth intercostal space, right sternal border.
▶ V2. Answer: Fourth intercostal space, left sternal border.
▶ V3. Answer: Equidistant between V2 and V4.
▶ V4. Answer: Fifth intercostal space, left midclavicular line.
▶ V5. Answer: Fifth intercostal space, anterior axillary line.
▶ V6. Answer: Fifth intercostal space, midaxillary line.
▶ The Electrocardiographic Grid and Waves. Answer: The EKG paper is a
graph paper with horizontal and vertical lines at 1-mm intervals. A heavy
line appears every 5mm.
▶ The horizontal axis represents time:. Answer: 1mm = 0.04 seconds
5mm = 0.2 seconds
▶ The vertical axis represents:. Answer: voltage, measures in millivolts
(1/1000 part of a volt) but expressed in millimeters: 0.1mV-1mm.
▶ The tracing is marked on the paper by a stylus using _____.. Answer:
heat
▶ The running speed of an EKG machine is _____.. Answer: 25mm/sec
▶ The EKG machine must be properly standardized so that 1mV will
produce a deflection of _____.. Answer: 10mm
▶ Define Waveform. Answer: Refers to movement away from the
isoelectric line either upward (positive) deflection or downward (negative)
deflection.
▶ Define Segment. Answer: Line between two waveforms.
▶ Define Interval. Answer: Waveform plus a segment.
