anatomy 2 mastering heart

What action causes the first heart sound heard through a stethoscope?

Closing of the atrioventricular valves

Part complete What action causes the second heart sound heard through a stethoscope?

Closing of the semilunar valves

Part complete Which part of the electrocardiogram (ECG) would most be affected by abnormally slow depolarization of the ventricles?

QRS wave

Part complete Which wave on the electrocardiogram (ECG) represents ventricular depolarization?

QRS wave

Which of the following can be used to measure heart rate?

R-R interval

The main pacemaker of the heart is the __________.

SA node

Part complete Determine the impact if the connection between the sinoatrial (SA) node and the atrioventricular (AV) node becomes blocked.

The ventricles will contract more slowly.

Part complete What activity is occurring in the heart during the Q-T interval on an electrocardiogram (ECG)?

The ventricular cells are undergoing action potentials.

The right and left coronary arteries receive blood from the:

aorta

What vessel delivers oxygenated blood to systemic capillaries for gas exchange?

aorta

Where should the left ventricle send blood?

aorta

Which vessel supplies the systemic circuit with oxygenated blood?

aorta

The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the:

atria.

What is NOT part of the cardiac conduction system?

atrioventricular (AV) valve

The electrical impulse is __________ as it passes through the AV node, which permits the atria to contract __________ ventricles.

delayed; before

The right side of the heart receives:

deoxygenated blood from the systemic circuit.

The apex of the heart is __________.

inferior

What characteristic differentiates cardiac muscle cells from skeletal muscle cells?

intercalated discs

Part complete Ventricular systole begins during the __________ phase of the cardiac cycle.

isovolumetric contraction

As ventricular systole begins, all four heart valves are closed during the:

isovolumetric contraction phase.

Blood returning from the lungs enters the __________.

left atrium

The pulmonary circuit involves blood flow from the heart to the:

lungs

Part complete The cells that rhythmically and spontaneously generate action potentials in the heart are called __________.

pacemaker cells

Part complete What muscles, present in the ventricles, anchor the atrioventricular valves by tendon-like chords called chordae tendineae?

papillary muscles

The AV valves close when __________.

pressure in the ventricles increases

What is the function of the valves in the heart?

prevent backflow of blood through the heart

Which vessel is guarded by a semilunar valve at its base?

pulmonary trunk

Part complete Which of the following does NOT return blood to the right atrium of the heart?

pulmonary vein

Which of the following vessels carries oxygenated blood?

pulmonary vein

What vessel(s) deliver oxygenated blood to the left atrium?

pulmonary veins

Blood in the right ventricle arrived from the:

right atrium.

Part complete What normally serves as the pacemaker of the entire heart?

sinoatrial (SA) node

Part complete The vessels that deliver oxygen to the tissues of the body are part of the __________.

systemic circuit

The aortic valve closes when __________.

the pressure in the left ventricle falls below aortic pressure

What valve prevents the backflow of blood from the right ventricle into the right atrium?

tricuspid valve

Part complete The left side of the heart is often called the systemic pump due to blood flow to the body.

true

Pressure in the aorta is greater than pressure in the pulmonary trunk; therefore, the left ventricle has to generate a greater pressure than the right ventricle in order to eject blood from the heart.

true

The left ventricle has greater muscle mass than the right ventricle since it pumps against greater resistance.

true

Both the left and right atria receive blood from:

veins.

Part complete During what phase does blood flow from the ventricles into the pulmonary trunk and aorta?

ventricular ejection phase

The T wave of an ECG corresponds to __________.

ventricular repolarization