Question

The normal pacemaker of the heart is the _____ node, which is found in the _____ atrium, and has an intrinsic firing rate of _____ beats/min.

a) SA, right, 60-100
b) AV, left, 40-60
c) AV, right, 100-120
d) SA, left, 20-40

Answer 1

The normal pacemaker of the heart is the sinoatrial (SA) node, located in the right atrium, with a firing rate of 60-100 beats per minute, resulting in the correct answer being a) SA, right, 60-100.

Step-by-step explanation:

The normal pacemaker of the heart is the sinoatrial (SA) node, which is found in the right atrium, and has an intrinsic firing rate of 60-100 beats/min. Therefore, the correct answer is a) SA, right, 60-100.

The SA node is responsible for initiating the sinus rhythm, or the normal electrical pattern that results in the contraction of the heart. This specialized clump of myocardial conducting cells has the highest inherent rate of depolarization and controls the heart rate in a resting state without nervous or endocrine influence. Other parts of the heart's conduction system can initiate impulses, but at a slower rate relative to the SA node.