Structure of the Heart Cell

By Anastasia Zoldak ; Updated April 24, 2017
Unlike these blood cells, heart cells appear as chain links under a microscope.

The cells of the heart are called cardiac myocytes, or cardiomyocytes. Scientists consider heart cells a part of the muscle cell family, though with unique differences in mitochondria, intercalated disks and t-tubes, as well as in cellular growth.

Under a Microscope

Technician using microscope.

Heart muscle cells build to form involuntary striated muscles strands, which form the walls of the heart, called the myocardium. Under a microscope, the striated muscle strands look like long chain links.


Medical model of human heart.

Unlike other muscle cells, heart cells are highly resistant to fatigue because they have more mitochondria organelles than any other cell in the body. Mitochondria are a cell’s “digestive system,” which breaks down nutrients into cell energy. This continuous supply of energy helps stop muscle fatigue.

Intercalated disks

Close up of an EKG.

Intercalated disks synchronize the contractions of all cardiomyocytes. Under a microscope they appear white and act as a double membrane to separate heart cells. These disks regulate the passage of positive and negative electrons. As electric currents repel and attract, it causes electron depolarization, which regulates heartbeat contractions.


Human heart in hand.

T-tubules, or transverse tubules, are plasma membranes that surround each cell and organize them into pairs to create the striated muscles strands used to build the myocardium. Other muscle strands in the body are grouped using four cells.

Cell Growth

3D rendering of human blood cells.

In 2009, scientists discovered that the cardiomyocytes of the human heart actually generate new heart cells. This discovery allows researchers to find ways of encouraging the heart to repair itself.

About the Author

Anastasia Zoldak is an experienced freelance writer and researcher based in Chicago. She has been a professional writer since 2007. Zoldak has an undergraduate degree in business, which she has used in a variety of industries, including retail, sales and recruiting. Prior to becoming a writer, she ran a successful business.