This blog post is a response to a student’s question under Habits of the Heart ( Valentine special)
PACEMAKER CELLS are cells that generate impulses by themselves and set the pace for how the heart pumps blood (They “make the pace”). They thus control the heart rate.
How are these cells able to generate impulses themselves?
They have unstable resting membrane potential that continue to depolarize.
Where are these pacemaker cells found?
They are found in the Sinoatrial Node (SA Node) of the heart. Remember that SA node?
It is located in the wall of the right atrium, just below the point where the superior vena cava enters the right atrium. The Sinoatrial node has a rate of impulse generation of about 75 times in one minute ( Remember normal heart rate is 60 – 100 beats per minute)
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