What is the role of Ca2+ in physiologic processes?

(i) Ca²⁺ is necessary for the activation of clotting enzymes in plasma,

(ii) Ca²⁺ controls membrane excitation, and Ca²⁺influx occurs during the excitatory process of nerve and muscle,

(iii) Ca²⁺ is bound to cell surfaces and has a role in the stabilization of the membrane and intercellular adhesion,

(iv) Ca²⁺ is necessary for muscle contraction,

(v) Ca²⁺ is essential in all excitation-secretion processes, both endocrine and exocrine. It also is essential for neurotransmitter release,

(vi) Ca²⁺ is necessary for the production of milk and the formation of bone and teeth,

(vii) Ca²⁺ acts as a second messenger in the cytosol,

(viii) Ca²⁺ has an essential role in the mineralization of bone.