NU 606 Exam 3: Chapter 12, 13, 25, 26
Study Guide Questions and Actual
Answers 2025\2026 Updated.
What are the two layers of the pericardial sac - Answer outer fibrous pericardium anchors the
heart to diaphragm
visceral pericardium (epicardium) has a serous membrane
what is unique about cardiac muscle (myocardial fibers) - Answer - no nerves are present
intercalated discs at the junctions between fibers (they contain desmosomes, connections to
prevent muscle cells from separating during contraction, and gap junctions, which permit ions
to pass from cell to cell which facilitates rapid transmission of impulses
what ensures that all muscle fibers of the two atria followed by the two ventricles contract
together or shortly after as it were - Answer gap junctions and desmosomes
where does a conduction impulse start - Answer all muscle cells can start it, but it usually
originates in the sinoatrial node - the pacemaker
what can alter the SA node impulses - Answer autonomic nervous system fibers and circulating
hormones such as epinephrine
what is the only anatomical connection between atrial and ventricle conduction in the heart -
Answer AV node
where does the cardiac electrical impulse go after the AV node - Answer av bundle/ bundle of
His, the right and left bundle branches, and the terminal purkinje network of fibers
what stimulates ventricular contraction - Answer terminal purkinje fibers?
what does the P wave represent in an ECG - Answer atrial depolarization
what does the QRS wave represent in an ECG - Answer depolarization of the ventricles - during
that time it masks the effect of atrial repolarziation
,where is the cardiac control center and what does it do - Answer medulla of the brain.
responds to changes from the baroreceptors (which detect BP and are located in the aorta and
carotid) . activate sympathetic nervous system or parasympathetic nervous system to alter the
rate and force of cardiac contractions
What does activation of the sympathetic nervous system (SNS) do? - Answer tachycardia and
contractility
What does activation of the parasympathetic nervous system do? - Answer bradycardia
through Vegas nerve
How do beta blockers work? - Answer block normal SNS activation in an otherwise damaged
heart, so that it does not need to increase force or rate after the heart has been damaged.
What are sulcus (sulci)? - Answer shallow grooves where the vessels of the coronary arteries lie
when is blood flow greater through the myocardium - Answer diastole (relaxation)
how does routine aerobic physical exercise help coronary circulation - Answer development of
collateral circulation
what does a blockage of the right coronary artery impact? - Answer AV node (resulting in
dysrhythmias), supplies right side of the heart and inferior portion of the left ventricle as well as
posterior interventriucular septum.
what does blockage of the left coronary artery impair? - Answer pumping capability of the left
ventricle - congestive heart failure- brings blood to anterior wall of ventricles, anterior septum,
and bundle branches
cardiac cycle step 1 - Answer atria relaxed and filling - the pulmonary veins filling the left
atrium, the inferior and superior venue cave fill the right atrium
cardiac cycle step 2 - Answer the av valves open as the pressure of the blood in the atria
increases and ventricles are relaxed
, cardiac cycle step 5 - Answer the atria relax
cardiac cycle step 6 - Answer the two ventricles begin to contract, and pressure increases in
the ventricles
cardiac cycle step 7 - Answer the av valves close
cardiac cycle step 8 - Answer all valves are closed, and the ventricular myocardium continues
to contract which builds pressure
cardiac cycle step 9 - Answer increase pressure opens the semilunar valves, blood is forced into
the pulmonary artery and aorta. right ventricle doesn't need as much pressure because the
pulmonary circulation is not as high pressure and systemic circulation.
cardiac cycle step 10 - Answer atria have begun to fill, ventricles relax, the aortic and
pulmonary valves close to prevent back flow.
what causes cardiac heart sounds - Answer valves closing - lubb is AV valves at systole, and
dubbings is semilunar valves closing with diastole
why is there a pause after AV node conduction - Answer allow ventricular filling
what impacts stroke volume - Answer sympathetic stimulation and venous return
Cardiac reserve is: - Answer the ability of the heart to increase cardiac output when needed
Preload - Answer volume of blood in ventricles at end of diastole - ventricles are at their
maximum volume
Afterload - Answer The force or resistance against which the heart pumps to eject blood from
the ventricles, deterred by peripheral resistance to the opening of semilunar valves - for
example impacted by high diastolic pressure :)
Study Guide Questions and Actual
Answers 2025\2026 Updated.
What are the two layers of the pericardial sac - Answer outer fibrous pericardium anchors the
heart to diaphragm
visceral pericardium (epicardium) has a serous membrane
what is unique about cardiac muscle (myocardial fibers) - Answer - no nerves are present
intercalated discs at the junctions between fibers (they contain desmosomes, connections to
prevent muscle cells from separating during contraction, and gap junctions, which permit ions
to pass from cell to cell which facilitates rapid transmission of impulses
what ensures that all muscle fibers of the two atria followed by the two ventricles contract
together or shortly after as it were - Answer gap junctions and desmosomes
where does a conduction impulse start - Answer all muscle cells can start it, but it usually
originates in the sinoatrial node - the pacemaker
what can alter the SA node impulses - Answer autonomic nervous system fibers and circulating
hormones such as epinephrine
what is the only anatomical connection between atrial and ventricle conduction in the heart -
Answer AV node
where does the cardiac electrical impulse go after the AV node - Answer av bundle/ bundle of
His, the right and left bundle branches, and the terminal purkinje network of fibers
what stimulates ventricular contraction - Answer terminal purkinje fibers?
what does the P wave represent in an ECG - Answer atrial depolarization
what does the QRS wave represent in an ECG - Answer depolarization of the ventricles - during
that time it masks the effect of atrial repolarziation
,where is the cardiac control center and what does it do - Answer medulla of the brain.
responds to changes from the baroreceptors (which detect BP and are located in the aorta and
carotid) . activate sympathetic nervous system or parasympathetic nervous system to alter the
rate and force of cardiac contractions
What does activation of the sympathetic nervous system (SNS) do? - Answer tachycardia and
contractility
What does activation of the parasympathetic nervous system do? - Answer bradycardia
through Vegas nerve
How do beta blockers work? - Answer block normal SNS activation in an otherwise damaged
heart, so that it does not need to increase force or rate after the heart has been damaged.
What are sulcus (sulci)? - Answer shallow grooves where the vessels of the coronary arteries lie
when is blood flow greater through the myocardium - Answer diastole (relaxation)
how does routine aerobic physical exercise help coronary circulation - Answer development of
collateral circulation
what does a blockage of the right coronary artery impact? - Answer AV node (resulting in
dysrhythmias), supplies right side of the heart and inferior portion of the left ventricle as well as
posterior interventriucular septum.
what does blockage of the left coronary artery impair? - Answer pumping capability of the left
ventricle - congestive heart failure- brings blood to anterior wall of ventricles, anterior septum,
and bundle branches
cardiac cycle step 1 - Answer atria relaxed and filling - the pulmonary veins filling the left
atrium, the inferior and superior venue cave fill the right atrium
cardiac cycle step 2 - Answer the av valves open as the pressure of the blood in the atria
increases and ventricles are relaxed
, cardiac cycle step 5 - Answer the atria relax
cardiac cycle step 6 - Answer the two ventricles begin to contract, and pressure increases in
the ventricles
cardiac cycle step 7 - Answer the av valves close
cardiac cycle step 8 - Answer all valves are closed, and the ventricular myocardium continues
to contract which builds pressure
cardiac cycle step 9 - Answer increase pressure opens the semilunar valves, blood is forced into
the pulmonary artery and aorta. right ventricle doesn't need as much pressure because the
pulmonary circulation is not as high pressure and systemic circulation.
cardiac cycle step 10 - Answer atria have begun to fill, ventricles relax, the aortic and
pulmonary valves close to prevent back flow.
what causes cardiac heart sounds - Answer valves closing - lubb is AV valves at systole, and
dubbings is semilunar valves closing with diastole
why is there a pause after AV node conduction - Answer allow ventricular filling
what impacts stroke volume - Answer sympathetic stimulation and venous return
Cardiac reserve is: - Answer the ability of the heart to increase cardiac output when needed
Preload - Answer volume of blood in ventricles at end of diastole - ventricles are at their
maximum volume
Afterload - Answer The force or resistance against which the heart pumps to eject blood from
the ventricles, deterred by peripheral resistance to the opening of semilunar valves - for
example impacted by high diastolic pressure :)
