The pacemaker of the heart is a bundle of cells that tells the heart when to beat. These cells are connected to the rest of the cells of the heart and communicate with them through electrical signals. The pacemaker cells set the pace (or rate) of the heartbeat.
The actual structure that serves as the heart's primary pacemaker is called the sinoatrial node (SA node). As described above, the SA node is a little bundle of cells located in the wall of the right atrium, the small upper chamber on the right side of the heart.
What if the SA node is knocked out for some reason? There are actually other regions of the heart that can act as pacemakers. These regions are known as latent pacemakers and include the atrioventricular node (AV node) and other cells that make up the electrical communication system of the heart (including special cells that make up the so-called Purkinje fibers of the heart). Even the cells that make up the large ventricles of the heart can set the pace of the heart.
Interestingly, each of the pacemakers described above has a different inherent rate that it "wants" the heart to beat at. For example, the SA node gets excited spontaneously at a rate of about 100 per minute. Some of the latent pacemakers might spontaneously get excited at a rate of 65 per minute or 45 per minute.
If that's the case, then wouldn't the heart just beat chaotically? How is it possible that the heart beats in a regular way with all of these different pacemakers lying around?
The reason is that under normal circumstances, only the SA node is active; all of the other latent pacemakers are basically inactive. Now, should the SA node fail, the AV node can take over. Likewise, if the AV node fails, cells that make up the Purkinje fibers can take over. And if even they fail, then the ventricular cells can take over as a last resort. There's lots of redundancy for this all-important organ.
Another type of pacemaker is the type that gets implanted by physicians. In patients with abnormal heart rates or rhythms, an artificial pacemaker can be implanted. These pacemakers serve the same purpose as the natural pacemakers of the heart: they control the regular rate and rhythm of the heart.
Although all of the heart's cells possess the ability to generate these electrical impulses (or action potentials), a specialized portion of the heart, called the sinoatrial node, is responsible for the whole heart's beat. The sinoatrial node(SA node) is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava. These cells are modified cardiac myocytes. They possess some contractile filaments, though they only contract relatively weakly. Cells in the SA node will spontaneously depolarize, resulting in contraction, approximately 100 times per minute. This native rate is constantly modified by the activity of sympathetic and parasympathetic nerve fibers, so that the average resting cardiac rate in adult humans is about 70 beats per minute. Because the sinoatrial node is responsible for the rest of the heart's electrical activity, it is sometimes called the primary pacemaker. http://en.wikipedia.org/wiki/Cardiac_pacemaker
The pacemaker is located on the outside of the right atrium.
A pacemaker is a device inserted into the heart to regulate the heart beats or heart rate
The heart.
The anatomical pacemaker is located in the right atrium
There are two pacemakers in the heart. One (which is the main pacemaker of the heart) can be found in the upper right-most part of the right atrium and the other one can be found in the center most part of the heart, inside the atrio-ventricular wall.
Pacemaker is located in the right atrium and generates electrical impulses to start a muscle contraction in the heart.
The adrenal medulla is the part of the brain that keeps the heart beating
The sinoatrial node is considered the pacemaker of the heart.
The sinoatrial node is impulse generating tissue in the (R) atrium of the heart. It is the natural pacemaker of the heart.
The atrioventricular (AV) node which is located in the right atrium. From there is travels down the septum, also called the atrioventricular bundle, and then spreads to all parts of the ventricles via the Purkinje fibers.
The primary pacemaker of a normal healthy heart is the sinus node (or SA node). It is located in the right atria of the heart.
No, the Sinoatrial Node is known as the natural pacemaker of the heart