What are satellite cells?
A undifferentiated cells
B cells that help with muscle growth and repair
C cell that help increase the number of nuclei within mature muscle cells (fibers)
D all of the above
D none of the above
The correct answer and explanation is:
Correct Answer: D. all of the above
Explanation:
Satellite cells are a type of stem cell found in skeletal muscle tissue. These cells are undifferentiated, meaning they have not yet specialized into a specific type of cell. They play a crucial role in muscle growth, repair, and regeneration.
Here’s how all the answer choices apply:
- A. Undifferentiated cells:
Satellite cells are considered undifferentiated because they have the potential to become different types of cells, specifically muscle cells. They remain in a quiescent (inactive) state until activated by muscle damage or stress. - B. Cells that help with muscle growth and repair:
When muscle fibers are damaged (due to injury or exercise), satellite cells become activated. They proliferate (multiply), then either fuse with existing muscle fibers to repair them or create new muscle fibers, contributing to muscle regeneration. - C. Cells that help increase the number of nuclei within mature muscle cells (fibers):
Mature skeletal muscle fibers are multinucleated, meaning they contain many nuclei. Satellite cells contribute additional nuclei to muscle fibers during growth or repair. These extra nuclei are vital for maintaining the large, protein-producing capacity needed by muscle fibers.
Thus, each statement accurately describes a key function of satellite cells, making the most complete and correct answer D: all of the above.
Importance in Health and Fitness:
In resistance training and bodybuilding, satellite cells are essential for muscle hypertrophy (growth). The more active and responsive these cells are, the better the muscle’s ability to adapt and recover. Moreover, with age, satellite cell activity declines, which contributes to reduced muscle repair and growth in older adults—a process known as sarcopenia. Therefore, understanding satellite cells has implications in sports science, aging, and muscular disorders.