What type of muscle tissue is the myocardium primarily made of?

The myocardium is primarily made of cardiac muscle tissue. This specialized type of muscle tissue is unique to the heart and is responsible for the involuntary contraction of the heart to pump blood throughout the body. Cardiac muscle fibers are striated, similar to skeletal muscle, but they are interconnected by intercalated discs, which allow for synchronized contractions and a communicative network that is essential for heart function.

In contrast, skeletal muscle is attached to bones and is under voluntary control, allowing for movement of the skeleton. Smooth muscle, found in the walls of hollow organs like the intestines and blood vessels, is also involuntary but lacks the striations characteristic of both cardiac and skeletal muscle. While striated muscle refers to muscle fibers that appear striped under a microscope, it encompasses both cardiac and skeletal types. Thus, the most specific and accurate classification for the tissue making up the myocardium is cardiac muscle.