Chapter 11 Part 1 Mastering

Which wave on the electrocardiogram (ECG) results from the firing of the sinoatrial (SA) node?

P

Blood leaves the left ventricle through an artery known as the

aorta

Which valve guards the base of the aorta and opens when the ventricles are contracting?

aortic semilunar valve

The two superior receiving chambers of the heart are known as the ________, while the two inferior discharging chambers of the heart are known as the ________.

atria; ventricles

The atrioventricular valves are closed when

atrial pressure is less than ventricular pressure

What part of the heart's intrinsic conduction system carries impulses into the interventricular septum?

atrioventricular (AV) bundle

Where does the sinoatrial node send an impulse after it initiates the electrical signal?

atrioventricular (AV) node

Pulmonary arteries transport

blood rich in carbon dioxide to the lungs

What are the tiny white cords that anchor the cusps or flaps of endocardium to the walls of the ventricles?

chordae tendineae

The heart sounds "lub" and "dup" result from

closure of the heart valves

The layer of the heart wall synonymous with the visceral layer of the serous pericardium is

epicardium

The layer of the heart wall that receives the stimulus from letter E is called the

myocardium

What is the function of the heart valves?

prevent backflow of blood

Which one of the following blood vessels carries oxygenated blood?

pulmonary vein

The sinoatrial node is located in the

right atrium

The tricuspid valve is located between the

right atrium and right ventricle

Which of the following is often called the pacemaker of the heart?

sinoatrial (SA) node

You notice a missing P wave on a patient's electrocardiogram (ECG) and believe there is a problem with the

sinoatrial (SA) node

Which of these will decrease heart rate?

stimulation by vagus nerves

What is the volume of blood pumped out of a ventricle with each heart beat?

stroke volume (SV)

Which of the following will slow the heart rate?

vagus nerve stimulation

What information can a clinician obtain from an electrocardiogram (ECG)?

abnormality in electrical activity of heart

Which of the following occurs when the pressure in the ventricles rises higher than the pressure in the atria?

Atrioventricular valves close.

The sinoatrial (SA) node is indicated by

Label A

The atrioventricular (AV) node is indicated by

Label B

The atrioventricular bundle (bundle of His) is represented by

Label C

The bundle branches are indicated by

Label D

The Purkinje fibers are indicated by

Label E

What chamber of the heart will blood enter after passing through the bicuspid valve?

Left Ventricle

Which blood vessels are direct branches of the left coronary artery?

anterior interventricular and circumflex arteries

An incompetent aortic semilunar valve would allow blood to backflow from the

aorta to the left ventricle

Which valve is closed during heart relaxation to prevent blood from backflowing from the aorta into the heart?

aortic semilunar valve

The pointed, inferior portion of the heart, known as the ________, rests on the diaphragm and is oriented toward the left hip.

apex

The first heart sound, "lub," is caused by the closure of the ________ valves.

atrioventricular (AV)

Which of the following increases heart rate?

epinephrine

The partition where the bundle branches are located is called the

interventricular septum

What structure divides the left ventricle from the right ventricle?

interventricular septum

All four heart valves are briefly closed as pressure begins to rise in the ventricles, a phase known as _

isovolumetric contraction

The transportation of blood from the right side of the heart to the lungs and back to the left side of the heart is known as ________ circulation.

pulmonary

Which vessels return oxygenated blood to the left atrium of the heart?

pulmonary veins

Through which valve will blood flow when leaving the right atrium?

tricuspid valve

The length of the cardiac cycle is normally ________ second(s) in length.

0.8

Which part of the intrinsic conduction system normally initiates the depolarizing impulse that causes a heartbeat?

SA node

Which valve is located between the right atrium and right ventricle?

tricuspid valve

During atrial diastole, blood flows from the atria to the _

ventricles

The heart is situated within the medial section of the thoracic cavity known as the

mediastinum

What is the muscular layer of the heart wall?

myocardium

The normal resting heart rate is about ________ times per minute.

75

Calculate the cardiac output if heart rate (HR) is 90 beats per minute, stroke volume (SV) is 110 ml/beatml/beat, end diastolic volume (EDV) is 140 mlml, and end systolic volume (ESV) is 30 mlml.

9.9 L/min

Which of these structures conduct(s) action potentials the slowest?

AV node

After ventricular contraction, the whole heart is briefly at rest and all the valves are closed. Which of the following statements best summarizes this early diastolic phase?

This is called isovolumetric relaxation and intraventricular pressure decreases.

An increase in sympathetic stimulation of the heart would increase stroke volume by increasing

contractility

Oxygented blood nourishing the myocardium comes from vessels that branch off the aorta called

coronary arteries

Which of the following supply the myocardium with oxygen-rich blood?

coronary arteries

The coronary veins empty blood from the myocardium into a large vein on the posterior side of the heart known as the

coronary sinus

Which of the following is NOT a major branch of the coronary arteries?

coronary sinus

Which vessel carries deoxygenated blood from cardiac circulation to the right atrium of the heart?

coronary sinus

Pulmonary circulation involves blood flow to and from the heart and the

lungs

Cardiac output is the product of which two variables?

heart rate and stroke volume

The vagus nerve operates under the control of the parasympathetic nervous system and causes the

heart rate to decrease

Pericarditis is most closely related to which of the following cardiac conditions?

inadequate amounts of serous fluid

The walls of the ________ are substantially thicker because that chamber acts as the more powerful systemic pump of the heart.

left ventricle

Which one of the following represents the correct path for the transmission of an impulse in the intrinsic conduction system of the heart?

sinoatrial (SA) node, atrioventricular (AV) node, atrioventricular (AV) bundle (bundle of His), right and left bundle branches, Purkinje fibers

The anatomy of the intrinsic conduction system causes contraction of the ventricles to begin at the apex and move superiorly. Why is this important?

so blood is forced upward, toward the semilunar valves

The volume of blood pumped out by each ventricle with each beat of the heart is called the

stroke volume

What term refers to the contraction of the heart?

systole

Which term means heart contraction?

systole

The mitral valve is normally closed

when the ventricle is in systole