Cardiovascular system - Canvas questions Flashcards
Which heart chamber has the thickest myocardial wall? Why?
The left ventricle as its responsible for pumping blood to all body tissues, therefore requires a more powerful contraction
Which coronary arteries create the anastomosis?
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Where are the pacemakers cells found?
sinus node
Does the nervous system need to electrically stimulate the heart? Why?
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How do electrical impulses spread from the SA node to myocytes?
initiation in the SA node throughout the atria through specialized internodal pathways, to the atrial myocardial contractile cells and the atrioventricular node.
Where is the atrial repolarization on the ECG?
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Is the ECG trace the result of a single action potential?
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What is called the phase preceding ventricular ejection in the cardiac cycle?
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What do heart sounds S1 represent?
closure of the atrioventricular (mitral and tricuspid) valves
How long does the cardiac cycle take?
approximately 0.8 seconds
What do heart sounds S2 represent?
closure of the semilunar (aortic and pulmonary) valves
What do heart sounds S3 represent?
often a sign of systolic heart failure
What is the first artery to branch off the aorta?
brachiocephalic trunk
What is the resting membrane potential of cardiac muscle tissue?
-90 mV
What valve separates the left atrium and left ventricle?
Mitral valve
