Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
The myocardium is the thick, muscular layer of the heart wall, composed of cardiac muscle cells that allow it to contract and pump blood throughout the body. It is situated between the outer epicardium and the inner endocardium layers of the heart.
Related terms
Cardiac muscle: Specialized muscle tissue found only in the heart that contracts rhythmically and involuntarily to pump blood.
Epicardium: The thin, outermost layer of the heart wall that serves as a protective layer covering the myocardium.