We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is the Myocardium?

Niki Acker
Updated Feb 27, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The myocardium is the muscle layer of the heart, responsible for the heart's pumping action, which supplies the entire body with blood. The myocardium consists of cardiac muscle, a type of muscle unlike any other muscle in the body. Cardiac muscle combines features of skeletal muscle, which controls voluntary body movement, and smooth muscle, which controls the movement of all body organs other than the heart.

The myocardium is the middle layer of the cardiac wall; the outermost layer is the epicardium, while the innermost is the endocardium. The epicardium consists mostly of connective tissue and serves to protect the inner structures of the heart. The endocardium is a thin layer of epithelial cells, similar to that which lines the inside of blood vessels.

The cardiac muscle that makes up this structure is involuntary, like the smooth muscle in the body's other organs. Involuntary muscle is not under conscious control, and contrasts with voluntary skeletal muscle, which is attached to the skeleton and used for skeletal movement like walking and standing. Cardiac muscle is more similar in structure, however, to skeletal muscle than to smooth muscle. Both cardiac muscle and skeletal muscle are striated, meaning the muscle fibers are arranged into parallel bundles, and have alternating thick and thin protein filaments. Striated muscle is better suited to brief, intense contractions than smooth muscle.

While skeletal muscle fibers are arranged into regular, non-branching bundles, the muscle fibers of the myocardium branch at irregular angles, and connect to other muscle cells at junctions called intercalated discs. The cells that make up cardiac muscle are called cardiac myocytes, or cardiomyocytes. They also differ from skeletal muscle cells in that they require extracellular calcium for contraction to take place.

The contractions of the myocardium are responsible for pumping oxygenated blood throughout the body, providing the body with the oxygen and other nutrients it needs to function properly. The heart muscle also pumps deoxygenated blood into the lungs so that it can be oxygenated again. After the blood has delivered oxygen throughout the body, deoxygenated blood returns to the heart, which in turn pumps the blood into the lungs. After the blood is reoxygenated in the lungs, it returns to the heart to be pumped throughout the body once again. Like all body tissues, the myocardium itself requires a blood supply in order to function; the coronary arteries supply the heart muscle with blood.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Niki Acker
By Niki Acker
"In addition to her role as a WiseGeek editor, Niki Foster is passionate about educating herself on a wide range of interesting and unusual topics to gather ideas for her own articles. A graduate of UCLA with a double major in Linguistics and Anthropology, Niki's diverse academic background and curiosity make her well-suited to create engaging content for WiseGeekreaders. "
Discussion Comments
By live2shop — On Jun 11, 2011

Did you know that heart attacks are on the decline?

This is because people are more aware of the causes of heart attacks and the symptoms. Emergency personnel can diagnose and treat a heart attack on the way to a hospital. Medical researchers have created medicines to help keep a heart victim alive. Doctors are also encouraging their patients to lower cholesterol levels even more.

Of course, getting plenty of exercise and eating heart healthy foods, can help that powerful muscle stay strong and healthy.

By Clairdelune — On Jun 10, 2011

I can see how our heart is crucial for life itself! This powerful muscle sends blood loaded with oxygen and nutrients through every part of the body. Then when the blood is out of oxygen, it comes back to the heart and then to the lungs to get loaded with oxygen again. I never realized just how the heart and lungs are so closely connected.

Another thing I didn't know is that calcium is essential for the heart to beat and pump blood.

The heart is a very strong muscle. You can surely tell that after you have been exercising hard for 45 minutes. You can really feel that heart bumping.

Niki Acker
Niki Acker
"In addition to her role as a WiseGeek editor, Niki Foster is passionate about educating herself on a wide range of...
Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.