A&P Chapter 17
tachycardia
Archie has a resting heart rate of 125 beats per minute. Classify his cardiac dysrhythmia.
cardiac pacemaker cells.
Autorhythmicity is the responsibility of:
vena cavae
Blood from the systemic circuit returns to the heart via the __________.
tricuspid valve and into the right ventricle.
Blood in the right atrium should travel next past the:
left atrium
Blood returning from the lungs enters the __________.
pulmonary trunk
Blood that leaves the right ventricle enters the __________.
the veins
Both the left and right atria receive blood from:
closes the AV valves
During the isovolumetric contraction phase, the pressure in the ventricles rises rapidly as the ventricles begin to contract. This high pressure ____________________________
120 ml.
End-diastolic volume for each ventricle during rest is normally about:
coronary sinus
Generally, coronary veins empty into a vessel known as the:
QRS wave
On an electrocardiogram (ECG), atrial repolarization is obscured by the:
3,6,1,4,2,5
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
Both AV valves are forced shut while both semilunar valves are forced open.
Predict the position of the valves when the ventricles contract.
70 ml per heart beat.
Stroke volume averages about:
ventricle increases
The AV valves close when __________.
ventricular repolarization
The T wave of an ECG corresponds to __________.
pressure in the left ventricle falls below aortic pressure
The aortic valve closes when __________.
inferior
The apex of the heart is __________.
left ventricle
The cardiac chamber with the thickest wall is the __________.
ventricles
The chambers that have just emptied when the second heart sound is heard are the __________.
chordae tendineae
The cusps of the atrioventricular valves attach directly to:
in the mediastinum
The heart is located _________.
mediastinum
The heart is situated in the middle of the thoracic cavity in a region known as the:
most pressure
The left ventricle has the thickest wall because it has to generate the
SA node
The main pacemaker of the heart is the __________.
sinoatrial (SA) node.
The right and left atria depolarize and contract following the arrival of the action potential from the:
aorta
The right and left coronary arteries receive blood from the:
pulmonary arteries
The right side of the heart pumps deoxygenated blood into _____.
deoxygenated blood from the systemic circuit.
The right side of the heart receives:
superior and inferior venae cavae
The two veins that drain the majority of the systemic circuit are the ____________________________
epicardium
The visceral pericardium is also known as the __________.
stroke volume
The volume of blood pumped by each ventricle in one heartbeat is known as:
SA node; parasympathetic NS
The____________ sets the heart rate at 100 beats per minute, but the ___________________ slows it down to 75 beats per minute.
The Frank-Starling law states that the more the ventricular muscle cells are stretched, the more forcefully they contract.
What best describes the Frank-Starling law?
intercalated discs
What characteristic differentiates cardiac muscle cells from skeletal muscle cells?
prevent backflow of blood through the heart
What is the function of the valves in the heart?
papillary muscles
What muscles, present in the ventricles, anchor by tendon-like chords called chordae tendineae?
the vibrations of the ventricular and blood vessel walls when valves shut
What produces the "lub dub" heart sounds?
right atrioventricular valve (tricuspid valve)
What valve prevents the backflow of blood from the right ventricle into the right atrium?
pulmonary semilunar valve
When the right ventricle contracts, blood passes through the _________________ into the pulmonary trunk
aorta
Where should the left ventricle send blood?
left ventricle
Which chamber experiences a maximum pressure of around 118 mm Hg during contraction?
vagus nerves (CN X)
Which cranial nerves have a negative chronotropic effect on heart rate?
atrial natriuretic peptide
Which hormone decreases cardiac output by decreasing blood volume and preload?
acetylcholine
Which of the following decreases heart rate?
pulmonary vein
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?
foramen ovale
Which opening in the interatrial septum of the fetal heart connects the right and left atrium?
the right marginal artery and the right posterior interventricular artery
Which two arteries arise from the right coronary artery?
pulmonary trunk
Which vessel is guarded by a semilunar valve at its base?
aorta
Which vessel supplies the systemic circuit with oxygenated blood?
QRS wave
Which wave on the electrocardiogram (ECG) represents ventricular depolarization?
