Sa node represents the pacemaker of our heart which is specialised in generating impluses and initiation of heart beat. it maintains the rhythmic contractile activity of heart. so it can only determine rate of heart beat and not contraction of heart muscles. contraction of heart muscles depends on how intense the impulse is which mainly decided by the conducting fibres.

Influence of Pace Maker on Heartbeat Rate

The pacemaker is a group of cells located in the sinoatrial node of the heart. It is responsible for initiating and regulating the heartbeat. The following are the ways in which the pacemaker influences the rate of heartbeat:

1. Initiates the heartbeat

The pacemaker cells generate electrical impulses that initiate the heartbeat. These impulses spread throughout the heart, causing the contraction of the heart muscles.

2. Regulates the heartbeat

The pacemaker cells also regulate the heartbeat by adjusting the rate and rhythm of the heartbeat. This is achieved through the release of hormones and neurotransmitters that affect the activity of the heart muscles.

3. Maintains a steady heartbeat

The pacemaker maintains a steady heartbeat by adjusting the rate of the heartbeat in response to changes in activity, stress, and other factors. This helps to ensure that the heart is able to meet the demands of the body and maintain adequate blood flow.

4. Controls heart rate during exercise

During exercise, the pacemaker increases the rate of the heartbeat to meet the increased demand for oxygen and nutrients by the muscles. This helps to ensure that the body is able to perform at its best during physical activity.

Conclusion

In summary, the pacemaker plays a crucial role in regulating the heartbeat. It helps to initiate the heartbeat, maintain a steady heartbeat, and control the heart rate during exercise. Understanding the influence of the pacemaker on the heart is important for the diagnosis and treatment of heart conditions.