Video Transcript
Where in the heart is the sinoatrial node located? (A) In the wall of the left ventricle, (B) in the wall of the right atrium, (C) in
the center of the septum, or (D) in the entrance to the aorta.
This question asks us about the location of the sinoatrial node. The sinoatrial node is one of the components of the electrical conduction system of
the heart. Let’s go over what we know about the sinoatrial node and figure out where in the
heart it is located.
As you may know, the heart’s regular, rhythmic beating is controlled by electrical
impulses. The sinoatrial node is a group of cells where electrical impulses in the heart
originate. This is why the sinoatrial node is called the pacemaker of the heart. It is responsible for controlling the rhythm of the heartbeat. You may be familiar with the fact that the heart has four chambers: two upper
chambers called atria and two lower chambers called ventricles.
As you can see in this diagram, the sinoatrial node can be found in the upper section
of the wall of the right atrium. At regular intervals, it generates an electrical signal. This signal spreads throughout the right atrium and downwards to the ventricles. This stimulates the contraction of the two ventricles, which pumps blood out of the
heart and to the rest of the body.
Let’s take a look at our answer choices. Option (B) provides us with the most appropriate description of the location of the
sinoatrial node. Therefore, the correct answer is (B), in the wall of the right atrium.
