What kind of muscle fibers are found in the heart?

The heart contains cardiac muscle fibers, which are specialized muscle cells unique to the heart muscle itself. Cardiac muscle fibers are striated, meaning they have a banded appearance under a microscope due to the organized arrangement of actin and myosin filaments. These fibers are involuntary, meaning they contract automatically and are not under conscious control.

Cardiac muscle fibers are specifically adapted to support the heart’s continuous and rhythmic contractions necessary for pumping blood throughout the body. They also have important features such as intercalated discs that facilitate electrical conduction and synchronized contraction between heart muscle cells.

While striated muscle fibers are indeed present in cardiac muscle, the correct term for the muscle fibers specifically found in the heart is "cardiac muscle fibers," distinguishing them from skeletal muscle fibers, which are also striated but have different functions and characteristics. Smooth muscle fibers, on the other hand, are found in the walls of hollow organs and are not applicable to the heart. Hence, the most accurate answer focusing on the type of muscle fibers specifically in the heart is cardiac muscle fibers.