How many layers does the heart have? correct answers 3
The base of the heart is the _______ portion of the heart. correct answers Superior
The apex is the ______ portion of the heart. correct answers Lower
How many chambers are called the: correct answers 4
The upper chambers are called the: correct answers Atria
The two upper chambers _______ blood. correct answers Pump
The two upper chambers ____ blood. correct answers receive
Pulmonary circulation occurs on the right side of the heart. It pumps _____ blood to the lungs.
correct answers CO2
The heart is divided into _______ chambers, but functions as a ______ sided pump. correct
answers 4:2
The right atrium receives venous blood from the head, neck, and thorax via the ____, from the
remainder of the body via the ______, and from the heart via the ____. correct answers Superior
vena cava; inferior vena cava; coronary sinus
The thick, muscular middle layer of the heart wall that contains the atrial and ventricular muscle
fibers necessary for contraction is the: correct answers myocardium
In most patients, the sinoatrial (SA) and atrioventricular (AV) nodes are supplied by the ____
coronary artery. correct answers Right
The intrinsie rate of the atrioventricular (AV) junction is: correct answers 40-60 bpm
What is the significance of a PR interval measuring less than 0.12 or more than 0.20 second?
correct answers The impulse followed an abnormal pathway or was delayed in the area of the
AV node.
How do you determine whether the atrial rhythm on an ECG tracing is regular or irregular?
correct answers Compare P to P intervals
_____ is the ability of cardiac cells to spontaneously initiate an electrical impulse without being
stimulated from another source ( such as a nerve). correct answers Automaticity
, In the heart's conduction system, the _____ receive(s) an electrical impulse from the bundle of
His and relay (s) it to the Purkinje fivers in ventricular myocardium. correct answers Right and
left bundle branches
In the heart's conduction system, the _____ receive (s) an electrical impulse from the right and
left bundle branches and relay (s) it to the ventricular myocardium. correct answers Purkinje
fibers
The ECG does not provide information about: correct answers The mechanical (contractile)
condition of the myocardium
What does the QRS complex represent? correct answers Ventricular depolarization
The normal pacemaker of the heart is the _____ , which is found in the _____. correct answers
SA node; right atrium
On an ECG, what is the first negative deflection seen after the p wave? correct answers Q wave
Where is the negative electrode placed in lead II? correct answers Right arm
Leads II, III, and a VF view the ____ surface of the heart. correct answers Inferior
The period during the cardiac cycle when cells cannot respond to a stimulus, no matter how
strong, is called the: correct answers Absolute refractory period
Leads I, a VL, V5, and v6 view the ____ surface of the left ventricle. correct answers Lateral
The absolute refractory period: correct answers Begins with the onset of the QRS complex and
terminates at approximately the apex of the T wave
The QT interval is measured: correct answers From the beginning of the QRS complex to the end
of the T wave
In an adult, the normal duration of the QRS complex is: correct answers 0.06-0.10 sec
Normally, the heart's primary pacemaker is the: correct answers SA node
The intrinsic rate of the Purkinje fibers is: correct answers 20-40 bpm
The PR interval is considered prolonged if it is more than _____ see in duration. correct answers
0.20
The intrinsic rate of the SA node is: correct answers 60-100 bpm
On the ECG, the T wave represents: correct answers Ventricular repolarization