Mastering Ch. 17 - The Cardiovascular System 1: The Heart
End-diastolic volume for each ventricle during rest is normally about:
120 ml
Blood returning from the lungs enters the ____.
Left atrium
Blood that leaves the right ventricle enters the ____.
Pulmonary trunk
Place the following parts of the cardiac conduction system in the order in which they transmit the action potential. 1) atrioventricular (AV) bundle 2) Purkinje fibers 3) sinoatrial (SA) node 4) right and left bundle branches 5) contractile cells of cardiac muscle tissue 6) atrioventricular (AV) node
3, 6, 1, 4, 2, 5
Calculate the end-systolic volume (ESV) if the end-diastolic volume (EDV) in a resting heart is 110 ml and stroke volume (SV) is 70 ml.
40 ml
How much blood is pumped from each ventricle during the ventricular ejection phase?
70 ml
Stroke volume averages about:
70 ml per heart beat
Which of the following decreases heart rate?
Acetylcholine
The right and left coronary arteries receive blood from the:
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
Which hormone decreases cardiac output by decreasing blood volume and preload?
Atrial natriuretic peptide
Predict the position of the valves when the ventricles contract.
Both AV valves are forced shut while both semilunar valves are forced open
Autohythmicity in the heart is the responsibility of ____.
Cardiac pacemaker cells
Autohythmicity is the responsibility of:
Cardiac pacemaker cells
The cusps of the atrioventricular valves attach directly to:
Chordae tendineae
Inotropic agents affect ____.
Contractility
Generally, coronary veins empty into a vessel known as the:
Coronary sinus
The right side of the heart receives ____.
Deoxygenated blood from the systemic circuit
The right side of the heart receives:
Deoxygenated blood from the systemic circuit
What largely determines preload?
End-diastolic volume (EDV)
The visceral pericardium is also known as the ____.
Epicardium
The visceral pericardium is the same as the ____.
Epicardium
Which opening in the interatrial septum of the fetal heart connects the right and left atrium?
Foramen ovale
High-pressured blood in the ventricles ____.
Forces the semilunar valves open
The heart is located ____.
In the mediastinum
The apex of the heart is ____.
Inferior
What characteristic differentiates cardiac muscle cells from skeletal muscle cells?
Intercalated discs
The cardiac chamber with the thickest wall is the ____.
Left ventricle
Which chamber experiences a maximum pressure of around 118 mm Hg during contraction?
Left ventricle
The heart is situated in the middle of the thoracic cavity in a region known as the:
Mediastinum
A damaged atrioventricular (AV) bundle or atrioventricular (AV) node will primarily affect the length of the ____.
P-R interval
What muscles, present in the ventricles, anchor by tendon-like chords called chordae tendineae?
Papillary muscles
During what part of the action potential will calcium ions enter the conctractile cell?
Plateau phase
The degree of stretch experienced by the sacromeres in the ventricle cells before they contract is caled ____.
Preload
The aortic valve closes when ____.
Pressure in the left ventricle falls below aortic pressure
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
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
On an electrocardiogram (ECG), atrial repolarization is obscured by the:
QRS wave
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
What valve prevents the backflow of blood from the right ventricle into the right atrium?
Right atrioventricular valve (tricuspid valve)
What valve prevents the backflow of blood from the right ventrile into the right atrium?
Right atrioventricular valve (tricuspid valve)
The main pacemaker of the heart is the ____.
SA node
The right and left atria depolarize and contract following the arrival of the action potential from the ____.
Sinoatrial (SA) node
The right and left atria depolarize and contract following the arrival of the action potential from the:
Sinoatrial (SA) node
What normally serves as the pacemaker of the entire heart?
Sinoatrial (SA) node
The volume of blood pumped by each ventricle in one heartbeat is known as:
Stroke volume (SV)
What two values are needed in order to calculate cardiac output (CO) for a ventricle?
Stroke volume (SV) and heart rate (HR)
Archie has a resting heart rate of 125 beats per minute. Classify his cardiac dysrhythmia.
Tachycardia
What best describes Frank-Sterling law?
The Frank-Sterling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract
The right side of the heart pumps deoxygenated blood into ____.
The pulmonary arteries (B in the figure)
Which two arteries arise from the right coronary artery?
The right marginal artery and the right posterior interventricular artery
What produces the "lub dub" heart sounds?
The vibrations of the ventricular and blood vessel walls when valves shut
Blood in the right atrium should travel next past the ____.
Tricuspid valve and into the right ventricle
Blood in the right atrium should travel next past the:
Tricuspid valve and into the right ventricle
Which cranial nerves have a negative chronotropic effect on heart rate?
Vagus nerves (CN X)
Both the left and right atria receive blood from ____.
Veins
Both the left and right atria receive blood from:
Veins
Blood from the systemic circuit returns to the heart via the ____.
Vena cavae
The chambers that have just emptied when the second heart sound is heard are the ____.
Ventricles
The T wave of an ECG corresponds to ____.
Ventricular repolarization
