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.
These cells can be replaced when smooth muscle is injured by trauma, surgery or disease. While during regeneration of skeletal muscle, only nearby precursor or satellite cells become activated and are the source of new muscle tissue, all smooth muscle cells have the ability to divide and form new smooth muscle.he cells in multi-unit muscles can function independently of each other, while the muscle cells of single-unit muscles work together as a unit. An example of multi-unit muscle cells are the cells that constrict or dilate the iris of the eye.