Each physical or health hazard is a âhazard classâ (e.g., Carcinogenicity is a hazard class). A âhazard classâ may be sub-divided in the criteria into. several âhazard categoriesâ based on the degree of. severity of the hazard.
Quick Answer. Calcium is a crucial part of muscle contraction. The ionic element is released from muscles during contraction and relaxation. The release of calcium helps propagate the muscle contraction and relaxation stages. Continue Reading.
During skeletal muscle contraction calcium ions expose myosin  binding sites on to the actin. When a nerve sends a signal to a  muscle to do some action the release of ace â¦ tylcholine at the  neuromuscular junction triggers calcium to be released into the  cytoplasm.