Question

Pacemaker is situated in the heart
A. In the wall of the right atrium
B. On interauricular septum
C. On interventricular septum
D. In the wall of the left atrium

Answer 1

Hint: Electrical impulses from the heart's nodal tissues cause your heart to beat (contract). This electrical signal begins within the sinoatrial (SA) node, located at the highest of the heart's upper-right chamber (the right atrium). The SAN is usually called the heart's natural pacemaker.

Complete answer: The heart has four different types of nodal tissues, among which the cardiac pacemaker cells are mostly found within the sinoatrial (SA) node, located within the upper part of the wall of the right auricle (or atrium).

These cells have natural automaticity, meaning they will generate impulses themselves.
It is a small mass of specialized cells within the top of the proper atrium (upper chamber of the heart).
It is responsible for generating the main threshold electrical impulses that cause the contraction and relaxation of the heart muscles, which we commonly know as heartbeats.
It allows the pacemaker to fireside when the heartbeat is just too slow.

So, the correct answer is “Option A”.

Note: It is important to note that the sinus node continuously generates electrical impulses, thereby setting the traditional rhythm and rate during a healthy heart. Hence, the pacemaker is mentioned because of the natural pacemaker of the guts. These cells form the cardiac muscle (or AV node), which is located between the left atrium of the heart, and the ventricle within the atrial septum, and it has the ability to take over the pacemaker responsibility.