EXAM 3-NURO 548 EXAM WITH
CORRECT QUESTIONS AND ANSWERS
2025
Where does rhythmic beating of the heart initiate? - CORRECT-ANSWERSSA
node
Where is the SA node? - CORRECT-ANSWERSR atrium
Where is the AV node located? - CORRECT-ANSWERSjunction of atria and
ventricles
Where does electrical current go after it leaves the AV node? - CORRECT-
ANSWERSPurkinjie fibers
Why is there a delay at the AV node? - CORRECT-ANSWERSTo give adequate
time for the ventricles to fill with blood
What is the intrinsic cardiac pacemaker? - CORRECT-ANSWERSSA node
BPM of the SA node? - CORRECT-ANSWERS60-100
BPM of the AV node? - CORRECT-ANSWERS40-60 bpm
What supplies blood to the SA node? - CORRECT-ANSWERSNormally (>65%)
supplied by a branch of RCA (Right Coronary Artery)
What supplies blood to the AV node? - CORRECT-ANSWERSright coronary
artery, or the LCx
In cardiac cells, is the cell more or less positive than the outside of the cell? -
CORRECT-ANSWERSOutside of a cardiac cell is more positive than the inside
of the cell.
,What electrical charge or stimulus is there needed to fire an action potential
in the heart to start the cardiac cycle? - CORRECT-ANSWERS-15 to -35 mV
Cardiac depolarization - CORRECT-ANSWERSa reversal of charges at a cell
membrane so that the inside of the cell becomes positive in relation to the
outside and sodium rushes into the cell
Cardiac repolarization - CORRECT-ANSWERSSodium ions returns to the
outside of the cell, potassium returns to the inside of the cell
Cardiac refractory period - CORRECT-ANSWERSInability of the heart to
generate summated contractions is the result of the long absolute refractory
period of the cardiac muscle while it waits for cellular membrane potential to
be restored
Is calcium higher inside or outside of cardiac cells? - CORRECT-
ANSWERSHigher extracellularly
What opens faster in cardiac cells - sodium or calcium channels? - CORRECT-
ANSWERSSodium
How is the action potential in the SA node produced? - CORRECT-
ANSWERSSelf generating as there is spontaneous depolarization
What does the SNS do to the heart? - CORRECT-ANSWERSIncreases HR and
contractility, therefore increasing cardiac output
What does the PSNS do to the heart? - CORRECT-ANSWERSDecreases heart
rate and contractility (but less impact on contractility compared to SNS)
What innervates the heart more, the SNS or PSNS? - CORRECT-ANSWERSSNS
,Norepinephrine and the SNS re: heart - CORRECT-ANSWERSNorepinephrine is
released and interacts with beta-1 receptors on cardiac muscle cells, leading
to increased contractility by promoting increased calcium influx
What does the PSNS release in the heart? - CORRECT-ANSWERSAch
What does the PSNS/Ach do to the heart? - CORRECT-ANSWERSIncreases
membrane permeability of the SA to K, thereby hyperpolarizing cell
membranes, and making them less susceptible to depolarization
P wave: EKG - CORRECT-ANSWERSatrial depolarization
PR interval EKG - CORRECT-ANSWERStime required for conduction of the
impulse through the atria, AV node, common bundle, bundle branches right
up to ventricular depolarization
QRS interval EKG - CORRECT-ANSWERSdepolarization of muscle fibers in the
ventricle
ST segment EKG - CORRECT-ANSWERSpause between the ventricular muscle
firing and repolarization of the ventricles
T wave EKG - CORRECT-ANSWERSventricular repolarization
U wave EKG - CORRECT-ANSWERSrepolarization of purkinje fibers
w/hypokalemia
Heart sounds pneumonic - CORRECT-ANSWERSS1YS2 -- systole occurs
between S1 and S2,
What do heart sounds indicate? - CORRECT-ANSWERSValve closure
The S1 heart sound represents: - CORRECT-ANSWERSclosure of the mitral
and tricuspid valves (AV) during SYSTOLE
, The s2 heart sound represents: - CORRECT-ANSWERSclosing of the aortic
and pulmonic valves during DIASTOLE
The s3 heart sound pneumonic - CORRECT-ANSWERSKentucky
The s4 heart sound pneumonic - CORRECT-ANSWERSTennessee
The s3 heart sound represents - CORRECT-ANSWERSpassive ventricular
filling, murmur, dilated heart/systolic dysfunction (S1, S2, S3)
The s4 heart sound represents - CORRECT-ANSWERSactive ventricular filling
- more common in hypertrophied heart, stiff ventricles, and diastolic
dysfunction (S4, S1, S2)
isometric contraction of the heart - CORRECT-ANSWERSfixed length during
course of the contraction during the initial phase of systole with increased
volume
preload - CORRECT-ANSWERSincrease in tension in ventricular cardiac
muscles when the ventricle expands in diastole
afterload - CORRECT-ANSWERSThe force or resistance against which the
heart pumps.
What does increased BP do to afterload and stroke volume - CORRECT-
ANSWERSIncreases afterload and decreases SV
How does blood flow through the heart? - CORRECT-ANSWERSInferior and
superior vena cava (1) dump blood into the right atrium (2)
Right ventricle (3)
2 pulmonary arteries (4) that lead to the lungs (5) where blood becomes
oxygenated
CORRECT QUESTIONS AND ANSWERS
2025
Where does rhythmic beating of the heart initiate? - CORRECT-ANSWERSSA
node
Where is the SA node? - CORRECT-ANSWERSR atrium
Where is the AV node located? - CORRECT-ANSWERSjunction of atria and
ventricles
Where does electrical current go after it leaves the AV node? - CORRECT-
ANSWERSPurkinjie fibers
Why is there a delay at the AV node? - CORRECT-ANSWERSTo give adequate
time for the ventricles to fill with blood
What is the intrinsic cardiac pacemaker? - CORRECT-ANSWERSSA node
BPM of the SA node? - CORRECT-ANSWERS60-100
BPM of the AV node? - CORRECT-ANSWERS40-60 bpm
What supplies blood to the SA node? - CORRECT-ANSWERSNormally (>65%)
supplied by a branch of RCA (Right Coronary Artery)
What supplies blood to the AV node? - CORRECT-ANSWERSright coronary
artery, or the LCx
In cardiac cells, is the cell more or less positive than the outside of the cell? -
CORRECT-ANSWERSOutside of a cardiac cell is more positive than the inside
of the cell.
,What electrical charge or stimulus is there needed to fire an action potential
in the heart to start the cardiac cycle? - CORRECT-ANSWERS-15 to -35 mV
Cardiac depolarization - CORRECT-ANSWERSa reversal of charges at a cell
membrane so that the inside of the cell becomes positive in relation to the
outside and sodium rushes into the cell
Cardiac repolarization - CORRECT-ANSWERSSodium ions returns to the
outside of the cell, potassium returns to the inside of the cell
Cardiac refractory period - CORRECT-ANSWERSInability of the heart to
generate summated contractions is the result of the long absolute refractory
period of the cardiac muscle while it waits for cellular membrane potential to
be restored
Is calcium higher inside or outside of cardiac cells? - CORRECT-
ANSWERSHigher extracellularly
What opens faster in cardiac cells - sodium or calcium channels? - CORRECT-
ANSWERSSodium
How is the action potential in the SA node produced? - CORRECT-
ANSWERSSelf generating as there is spontaneous depolarization
What does the SNS do to the heart? - CORRECT-ANSWERSIncreases HR and
contractility, therefore increasing cardiac output
What does the PSNS do to the heart? - CORRECT-ANSWERSDecreases heart
rate and contractility (but less impact on contractility compared to SNS)
What innervates the heart more, the SNS or PSNS? - CORRECT-ANSWERSSNS
,Norepinephrine and the SNS re: heart - CORRECT-ANSWERSNorepinephrine is
released and interacts with beta-1 receptors on cardiac muscle cells, leading
to increased contractility by promoting increased calcium influx
What does the PSNS release in the heart? - CORRECT-ANSWERSAch
What does the PSNS/Ach do to the heart? - CORRECT-ANSWERSIncreases
membrane permeability of the SA to K, thereby hyperpolarizing cell
membranes, and making them less susceptible to depolarization
P wave: EKG - CORRECT-ANSWERSatrial depolarization
PR interval EKG - CORRECT-ANSWERStime required for conduction of the
impulse through the atria, AV node, common bundle, bundle branches right
up to ventricular depolarization
QRS interval EKG - CORRECT-ANSWERSdepolarization of muscle fibers in the
ventricle
ST segment EKG - CORRECT-ANSWERSpause between the ventricular muscle
firing and repolarization of the ventricles
T wave EKG - CORRECT-ANSWERSventricular repolarization
U wave EKG - CORRECT-ANSWERSrepolarization of purkinje fibers
w/hypokalemia
Heart sounds pneumonic - CORRECT-ANSWERSS1YS2 -- systole occurs
between S1 and S2,
What do heart sounds indicate? - CORRECT-ANSWERSValve closure
The S1 heart sound represents: - CORRECT-ANSWERSclosure of the mitral
and tricuspid valves (AV) during SYSTOLE
, The s2 heart sound represents: - CORRECT-ANSWERSclosing of the aortic
and pulmonic valves during DIASTOLE
The s3 heart sound pneumonic - CORRECT-ANSWERSKentucky
The s4 heart sound pneumonic - CORRECT-ANSWERSTennessee
The s3 heart sound represents - CORRECT-ANSWERSpassive ventricular
filling, murmur, dilated heart/systolic dysfunction (S1, S2, S3)
The s4 heart sound represents - CORRECT-ANSWERSactive ventricular filling
- more common in hypertrophied heart, stiff ventricles, and diastolic
dysfunction (S4, S1, S2)
isometric contraction of the heart - CORRECT-ANSWERSfixed length during
course of the contraction during the initial phase of systole with increased
volume
preload - CORRECT-ANSWERSincrease in tension in ventricular cardiac
muscles when the ventricle expands in diastole
afterload - CORRECT-ANSWERSThe force or resistance against which the
heart pumps.
What does increased BP do to afterload and stroke volume - CORRECT-
ANSWERSIncreases afterload and decreases SV
How does blood flow through the heart? - CORRECT-ANSWERSInferior and
superior vena cava (1) dump blood into the right atrium (2)
Right ventricle (3)
2 pulmonary arteries (4) that lead to the lungs (5) where blood becomes
oxygenated
