Which cellular organelles are absent in the cardiac muscle cell?

Cardiac muscle cells, or cardiomyocytes, lack certain organelles typically found in other cell types. Notably, they have fewer mitochondria compared to skeletal muscle cells, but they do contain many due to their high energy demands. However, they generally do not have a well-developed smooth endoplasmic reticulum or large amounts of glycogen granules, which are more prevalent in other types of muscle cells. Additionally, cardiac muscle cells lack satellite cells, which are involved in muscle repair and regeneration in skeletal muscle.