Military forces have worn distinctive uniform items for centuries to create a psychological advantage and boost their esprit de corps, but the military use of berets is a relatively recent phenomenon. In the 16th and 17th centuries, the Blue Bonnet became a de facto symbol of Scottish Jacobite forces.
Muscle cells have adapted to their job by contracting and relaxing.  When calcium levels are increased the muscle cells contract. On the  other hand, when calcium levels droâ¦p the muscle cells get relaxed.
This page follows on from the more general page about the structure of muscle. Skeletal muscles consist of 100,000s of muscle cells (also known as muscle fibers) that perform the functions of the specific muscle of which they are a part.ore about the contents of cells generally, is available on the page about animal cells. The components of skeletal muscle cells that are specific to muscle tissue are myofibrils. 1  Each muscle fibre ( muscle cell ) is covered by a plasma membrane sheath which is called the sarcolemma.