Cardiac muscle fibers are specialized cells found in the heart, responsible for its contraction and pumping blood throughout the body. These fibers are striated, meaning they have a banded appearance, and are interconnected by structures called intercalated discs, which allow for synchronized contractions. Unlike skeletal muscle fibers, cardiac muscle fibers are involuntary, meaning they operate without conscious control. They have a high density of mitochondria, providing the energy needed for continuous activity, and can generate their own electrical impulses, allowing the heart to maintain a steady rhythm essential for proper function.