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