Mechanisms of Ventilation and pulse rates

In my recent blogs I have explained about the respiratory system, blood and understanding the circulation and structure of blood as well as probably the most important muscle in our body the heart. So what makes all these complexities tick so to speak. How does it all happen and more important what makes our heart beat. It all comes down to one thing, the brain. Actually the cardiovascular part of the brain to be precise. Our brain is responsible for many things, therefore it has many parts to deal with these demands. The cardiovascular part is found within the medulla oblongata, which is located at the bottom of the brainstem. It is within the medulla oblongate that the motor nerves which are responsible for carrying action potentials from the brain to the heart is situated. It is these nerves that are connected to the Sinoatrial Node (SAN) and stimulate the SAN to either speed up or slow down depending on the body's needs.

The response of the medulla depends on the action potentials received by the SAN from baroreceptors. Situated within the aorta they are stimulated when the aorta wall is streched (increase output). So basically the SAN acts as the pacemaker by generating at regular intervals the electrical impulses of the heart beat so maintaining normal cardiac rhythm and pulse rates.