The muscle that makes up the heart is called the cardiac muscle. It is also known as the myocardium. The thick muscles of the heart contract to pump blood out and then relax to let blood back in after it has circulated through the body. The interossei muscles begin between the bones of the hand. There are four dorsal and three palmar interossei muscles. While all interossei bend the MCP joints, the dorsal interossei allow us to spread our fingers away from each other. The palmar interossei pull our fingers together.
Cardiac muscle makes up the wall of the heart and is responsible for the forceful contraction of the heart. Smooth muscles make up the walls of the intestine, the uterus, blood vessels, and internal muscles of the eye. Skeletal muscles are attached to the bones and in some areas the skin (muscles in our face).
