okay, here are the first few:
1) what is the difference between muscle dystrophy and muscle atrophy, or are they the same thing?
They are not the same thing. Muscle atrophy is a wasting away of muscle from disuse or poor nutrition, and can be total or partial loss of function associated with the lessening of muscle mass secondary to nervous, vascular or nutritional causes. Muscle dystrophy is a degeneration of the muscles or any organs caused by a disease process, and can also be caused by malnutrition. Dystrophy is primarily a disease of the muscle itself, and it caused by mostly genetic factors.
2) what is the difference between IGF-1 and MGF?
When a person’s pituitary glands release human growth hormone, it causes the liver to release IGF-1. IGF-1 is at its highest in childhood and stimulates muscle growth. MGF is a variant of IGF-1, and stimulates myoblasts division and allows for muscle fibers to fuse and mature. (Myoblasts are undifferentiated cells in the mesoderm of the vertebrate embryo that is a precursor of a muscle cell.) The difference between IGF-1 and MGF is that IGF-1 stimulates cell growth in muscles, kidneys, bones, liver, lungs, and nerves (among other body cells) and MGF stimulates myoblasts division through stimulation of different receptors.
3) how does intensive exercise lead to the buildup of muscles?
Forced lengthening of the muscle with high weight loads causes microscopic tears in the small fibers that make up the muscle and connective tissues. Thus, the muscle is physically damaged. After exercise, fluid begins to build up in the damaged cells in order to bring in immune cells such as neutrophils and macrophages to the site of injury. The muscle cells are then repaired, muscle energy is replenished, and the fibers are built back up bigger and stronger than before.
