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.
All muscle cells produce adenosine triphosphate (ATP) molecules which are used to power the movement of the myosin heads. Muscles conserve energy in the form of creatine phosphate which is generated from ATP and can regenerate ATP when needed with creatine kinase.Muscles also keep a storage form of glucose in the form of glycogen. Glycogen can be rapidly converted to glucose when energy is required for sustained, powerful contractions.uscles conserve energy in the form of creatine phosphate which is generated from ATP and can regenerate ATP when needed with creatine kinase. Muscles also keep a storage form of glucose in the form of glycogen.