Mastering A&P Assignment #4: The Heart – Flashcards

Into which chamber of the heart will blood flow next after the vessel indicated by the red arrow? Left atrium Right ventricle Right atrium Left ventricle

Blood returning to the heart from the pulmonary circuit first enters the __________. right atrium pulmonary valve pulmonary trunk left atrium

The papillary muscles function to __________. close the AV valves eject blood from the ventricles push blood from the atria into the ventricles prevent the AV valves from reversing into the atria

The __________ valve prevents backward flow of blood into the left ventricle. aortic tricuspid bicuspid pulmonic

The pulmonary veins carry __________ blood to the __________ atrium. deoxygenated; right oxygenated; right deoxygenated; left oxygenated; left

Which of the labeled valves will open during ventricular systole to allow the flow of blood to the lungs?

Which of these organs is not found in the mediastinum? trachea esophagus pericardial sac lung

The epicardium is also known as the __________. endocardium myocardium visceral pericardium parietal pericardium

The heart is actually (one, two, or three) pumps? two pumps one pump three pumps

Which chamber receives blood from the superior and inferior vena cavae? right atrium left ventricle left atrium right ventricle

Which heart chamber receives blood from the pulmonary veins? right ventricle left ventricle right atrium left atrium

Which heart chamber pumps unoxygenated blood out the pulmonary trunk? left atrium right atrium left ventricle right ventricle

Which chamber pumps oxygenated blood out the aorta to the systemic circuit? right atrium left atrium left ventricle right ventricle

What is the function of the structures indicated by the red arrow (intercalated discs)? Propagate action potentials from cell to cell Transfer force of contraction from cell to cell Permit strong connections between adjacent cells All of the listed responses are correct.

Which of the following will receive electrical impulses next, after the structure indicated by the red arrow? Auricles of the right and left atria Interventricular septum Apex of the heart Pacemaker cells

Which of these is an important difference between cardiac muscle and skeletal muscle? Cardiac muscle contracts spontaneously. Skeletal muscle is striated. Cardiac muscle can't be tetanized. Cardiac muscle lacks troponin.

Heart rate is controlled by __________. the phrenic nerves both the right vagus and sympathetic nerves sympathetic nerves in the cardiac plexus the right vagus nerve

The P wave of the electrocardiogram is closely followed by __________. contraction of the right atrium contraction of the left atrium relaxation of both atria contraction of both atria

During the plateau phase of the cardiac action potential, which ion is entering the cardiac muscle cell? potassium sodium hydrogen calcium

Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart? SA node Purkinje fibers AV bundle (bundle of His) AV node

What does the ECG wave tracing represent? contraction of the heart electrical activity in the heart

What does the QRS complex represent in the ECG wave tracing? atrial depolarization ventricular repolarization atrial repolarization ventricular depolarization

Contraction of the atria results from which wave of depolarization on the ECG tracing? T wave P wave QRS complex

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles? SA node Purkinje fibers AV bundle (bundle of His) bundle branches AV node

Which wave is the largest in the electrocardiogram? P Q S R

The rapid depolarization phase in the ventricular action potential appears in the electrocardiogram as the __________. QRS complex P wave T wave PR segment

Ventricular systole begins with the __________. closing of the mitral valve opening of the mitral valve opening of the aortic valve closing of the aortic valve

Compared to the right ventricle, which of these statements about the left ventricle is false? It ejects more blood. It generates a higher pressure. It has a thicker wall. It makes a louder heart sound.

During ventricular systole the blood pressure __________ and ventricular volume __________. increases; decreases decreases; increases increases; increases decreases; decreases

Which of these statements concerning the cardiac cycle is false? Cardiac cycle begins with atrial systole. AV valves close before semilunar valves open. Ventricular systole begins at the peak of atrial systole. Aortic pressure is greater than pulmonary trunk pressure.

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________. ventricular systole ventricular diastole

Which of the following is correct about the filling of the ventricles? The majority of ventricular filling is caused by contraction of the atria. Most blood flows passively into the ventricles through open AV valves.

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves. Pressure in the ventricles would be greater than in the atria. Pressures in the atria and ventricles would be equal. Pressure in the atria would be greater than the pressure in the ventricles.

What causes the aortic semilunar valve to close? equal ventricular and aortic pressures higher ventricular pressure than aortic pressure greater pressure in the aorta than in the left ventricle

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling. isovolumetric contraction, ventricular ejection, isovolumetric relaxation ventricular ejection, ventricular relaxation, isovolumetric contraction isovolumetric relaxation, ventricular ejection, isovolumetric contraction ventricular ejection, isovolumetric contraction, isovolumetric relaxation

Increased pressure in the ventricles would close what valve(s)? both semilunar and AV valves semilunar valves only AV valves only

The wall of the left ventricle is thicker than the right; the left ventricle pumps more blood than the right. Are these two statements true or false? Both statements are true. The first is true; the second is false. Both statements are false. The first is false; the second is true.

What is the relaxed state of the ventricle called? ventricular ejection diastole systole ventricular filling

The one-way nature of the left AV valve prevents blood flow from _________. the aorta to the left ventricle the left ventricle to the left atrium the left atrium to the left ventricle the left ventricle to the aorta

The closing of the left AV valve occurs near the beginning of __________. ventricular systole isovolumetric relaxation atrial systole ventricular diastole

The majority of ventricular filling occurs while the ventricles and atria are in what state(s)? ventricular systole and atrial diastole ventricular systole and atrial systole ventricular diastole and atrial systole ventricular and atrial diastole

Which of the following most correctly describes end-diastolic volume? the volume of the ventricle when it is least full the volume of the ventricle at the end of atrial diastole the volume of the ventricle when it is most full the increase in ventricular volume during atrial systole

Left ventricular filling occurs __________. while the AV valve is open during ventricular systole while the semilunar valve is open during isovolumetric relaxation

Heart valves are in what state during isovolumetric contraction? The AV valves and semilunar valves are closed. The AV valves are open, and the semilunar valves are closed. The AV valves and semilunar valves are open. The AV valves are closed, and the semilunar valves are open.

The decrease in left ventricular pressure at the end of ventricular systole causes __________. isovolumetric contraction the semilunar valve to close the AV valve to close the semilunar valve to open

Ventricular diastole begins with the closing of the semilunar valves. What phase of the cardiac cycle happens between this event and the later opening of the AV valves? atrial systole isovolumetric relaxation ventricular ejection isovolumetric contraction

The volume of blood remaining in the ventricle as diastole begins is called the __________. stroke volume end-systolic volume end-diastolic volume cardiac reserve

Which of the following factors will decrease cardiac output? stimulation of the vagus nerve increased venous return increased preload sympathetic activation

Which of the following would increase cardiac output to the greatest extent? increased heart rate and increased stroke volume decreased heart rate and increased stroke volume increased heart rate and decreased stroke volume decreased heart rate and decreased stroke volume

Which of the following would increase heart rate? acetylcholine increased activity of the parasympathetic nervous system epinephrine and norepinephrine decreased activity of the sympathetic nervous system

How would an increase in the sympathetic nervous system increase stroke volume? increased end systolic volume increased end diastolic volume increased contractility decreased end diastolic volume

By what mechanism would an increase in venous return increase stroke volume? increased contractility increased end systolic volume decreased end diastolic volume increased end diastolic volume

How would a decrease in blood volume affect both stroke volume and cardiac output? increased stroke volume and increased cardiac output no change in stroke volume and decreased cardiac output decreased stroke volume and decreased cardiac output decreased stroke volume and no change in cardiac output

Which of the following will not increase heart rate? faster rise of the pacemaker potential increased sympathetic stimulation of the SA node increased parasympathetic stimulation of the SA node increased levels of circulating epinephrine

Which of these responses by the heart will sympathetic stimulation not cause? increased heart rate increased cardiac output increased end-systolic volume increased stroke volume

Which of these is not needed to determine cardiac output? end systolic volume end diastolic volume blood pressure heart rate

If you know both the heart rate and stroke volume, you can calculate the __________. end-diastolic volume end-systolic volume ejection fraction cardiac output

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane? desmosomes tight junctions intercalated discs gap junctions

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion? sodium calcium potassium

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane? fast sodium slow calcium fast calcium potassium

Repolarization of an autorhythmic cell is due to the opening of which channels? voltage-gated potassium channels Chemically gated potassium channels chemically gated calcium channels voltage-gated sodium channels

In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells? the flow of positive ions from adjacent cells the flow of negative ions from adjacent cells an unstable resting membrane potential in the contractile cells