The Heart’s Electrical and Physical Function
The heart is an organ, which pumps blood all over the body; it is made up of muscle tissue. Just like any other pump, the heart requires a source of energy in order to carry out its function. The energy supplied to the heart comes from an electrical system within the body.
The source of the electrical stimulus is the sinus node, which is also known as sinoatrial node (SA node). According to GW Heart and Vascular Institute, the Sinus node comprises special tissues located in the right atrium of the heart. The SA node produces electrical stimulus at a rate of 60-100 times per minute under ordinary situations (1). Once the electrical stimuli are generated, they are sent through pathways conduction, which in turn makes the heart muscle to contract in order to pump blood. The electrical signal travels along the defined pathways, which stimulate the cells along the pathways. The cells then activate the next cell sequentially, making the heart to expand and contract in a coordinated manner, thus creating a heartbeat (Desai 1:26-3:00). Therefore, the synchronized heartbeat physically pumps the blood to all body parts.
For the heart to function properly the left and the right atria, which are the top chambers of the heart are stimulated first. Then the left and the right ventricles, which are the lower parts of the heart, are stimulated after a short while. The electrical stimulation from the sinus node travels to the atrioventricular (AV) node where it stops and then continues through the conduction pathways where it stimulates the ventricles. The atria contract for a moment as the ventricles empty the blood. Once the blood is emptied, it travels from the heart to the rest of the body through the bloodstreams (GW Heart and Vascular Institute 1). The SA node then sends another electrical pulse to the atria, which initiates the whole process again, blood is then pumped back to the heart, and the cycle continues.