Multiple Choice
Why is the sinoatrial node the heart's normal pacemaker?
A) It has the fastest natural rate of autorhythmicity.
B) It has both sympathetic and parasympathetic innervation.
C) It lies in the right atrium.
D) Activation of K+ channels occurs more rapidly in this region than elsewhere in the heart.
Correct Answer:

Verified
Correct Answer:
Verified
Q6: The EDV of the heart averages about
Q36: Match the pressure relationships, labelled a. through
Q141: Which of the following ECG waves represents
Q176: Increased EDV results in decreased stroke volume.
Q190: Diastole refers to the period of cardiac
Q196: Use the answer code below to complete
Q203: Match the EKG features, labelled a. through
Q208: Left-sided congestive heart failure can lead to
Q219: The _ is the volume of blood
Q263: Most ventricular filling is accomplished during atrial