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.
Review of the process in skeletal muscle: Skeletal muscle has a well-defined system for producing excitation of the skeletal muscle cells. An alpha-motoneuron innervates the muscle cell, forming a neuromuscular junction.n addition, the neurotransmitter can bind to any one of the nearby smooth muscle cells, a flexibility not found in the NMJ. The chemicals that influence smooth muscle cells: As you'll recall, there is only one neurotransmitter released at the neuromuscular junction-acetylcholine.