I heard skeletal muscle cells divide. Does that mean people with long term anorexia or who experienced starvation would have permanent loss?

Skeletal muscle cells, in general, do not divide and are considered terminally differentiated. They can, however, undergo hypertrophy (increase in size) or atrophy (decrease in size) in response to various stimuli, including exercise and nutrition.

In the case of long-term anorexia or starvation, the body enters a state of energy deprivation, which can lead to the breakdown of muscle tissue. However, this process is usually reversible, and with proper nutrition and medical care, individuals can regain muscle mass and strength.

Here's a more detailed explanation:

1. Muscle Wasting during Anorexia or Starvation:

- During periods of severe energy restriction, the body prioritizes energy conservation and may break down muscle tissue to release stored energy (amino acids).

- This process, known as muscle atrophy, involves the degradation of muscle proteins and the loss of muscle mass and strength.

2. Muscle Cell Division:

- Under normal circumstances, skeletal muscle cells are post-mitotic, meaning they have lost the ability to divide.

- However, there are some exceptions, such as satellite cells, which are specialized muscle stem cells that can proliferate and contribute to muscle growth and repair.

3. Muscle Regeneration:

- In response to injury, trauma, or intense exercise, satellite cells can become activated and divide to produce new muscle cells (myoblasts).

- These myoblasts then fuse together to form new muscle fibers and repair damaged tissue.

4. Reversibility of Muscle Loss:

- While long-term anorexia or starvation can lead to significant muscle loss, this process is generally reversible.

- With proper nutrition, including adequate protein intake, exercise, and medical care, individuals can regain muscle mass and strength.

- The extent and rate of recovery may vary depending on the severity of the initial muscle loss and the individual's overall health.

It's important to note that severe anorexia and starvation can have several adverse health effects beyond muscle loss, and seeking professional medical help is crucial for managing and recovering from these conditions.