I like to get into discussions with my partners about EMS topics and find out which topics we can increase our knowledge. It helps us improve in explaining ourselves and also keeps us abreast on topics. I personally notice that many EMTs can’t explain the basic functionality of the heart and it’s circulation of blood flow. So I drew a little diagram and wrote a little explanation about it.
Basically the heart pumps approximately 7,000 liters of blood through the body each day. The process starts with the right side of the heart or the pulmonary side. Blood that is low in oxygen and high in carbon dioxide comes into the right atrium through the superior and inferior vena cava from the body. As the right atrial wall contracts, this blood passes through the tricuspid valve and into the right ventricle. Once into the right ventricle, the ventricular wall contracts and the tricuspid valve closes pushing the blood into the pulmonary artery, where it is oxygenated in the lungs.
Now we move onto the left side of the heart or the systemic side. Now this blood that was oxygenated in the lungs, and is now high in oxygen and low in carbon dioxide, comes back to the heart through the pulmonary veins and into the left atrium. As the left atrial wall contracts, blood moves through the bicuspid valve (or mitral valve) and into the left ventricle, which is the strongest part of the heart. When the left ventricular wall contracts, the blood moves through the aorta and feeds the rest of the body.
An instructor once taught me this diagram and I drew it out for you to use. It’s a simple diagram of the heart instead of the 3D image where you can’t really tell which side of the heart is the left and which side of the heart is the right. I hope you enjoyed this post about blood flow through the heart. Let me know if you like it and I will start doing more of these.