Topic summary
Cardiomyocytes
Extracted from the Wikipedia article Cardiac muscle.
Microanatomy
Cardiomyocytes contain T-tubules, pouches of cell membrane that run from the cell surface to the cell's interior which help to improve the efficiency of contraction. The majority of these cells contain only one nucleus (some may have two central nuclei), unlike skeletal muscle cells which contain many nuclei. Cardiac muscle cells contain many mitochondria which provide the energy needed for the cell in the form of adenosine triphosphate (ATP), making them highly resistant to fatigue.