Calcium regulation has significant effects on the human body's ability to maintain homeostasis. About 99% of the body's calcium is found in the skeleton in the form of calcium salts. The remaining 1% is found in the blood and is controlled within a very narrow range by an elaborate system of controls to ensure key processes (Marieb & Hoehn 2010). Calcium is the most abundant cation in the human body, vital for the normal functioning of a number of processes including: nerve excitability, hormone secretion, blood coagulation, taste transduction, muscle function and cell adhesion (Hutchins 2014). This essay will outline some of the most important roles of calcium metabolism. The essay will begin by discussing how calcium promotes bone growth and calcium stores, then discuss the importance of calcium in muscle contraction and a brief overview of calcium signaling tools. The final section will then move on to consider chemical synapses. This essay will argue that calcium regulation is a key and integral element to human life. BonesCalcium (Ca+, Ca2+) is a mineral that is integral to the formation, growth and maintenance of healthy bones. Bone formation or osteogenesis is an essential process that begins before the eighth week in a human embryo and continues until approximately age 25 (Hill 2014). Bones and the skeleton not only protect the organs and support the body, but they also account for 99% of the body's total calcium and function as a reserve that can be released into the body when needed. Non-crystalline forms of bone salts combine with Ca2+Pi to instinctively form tiny hydroxyapatite crystals which then further catalyze the crystallization of calcium salts in that area. The calcium salts are deposited... in the center of the sheet... 521/Marieb, E & Hoehn, K. (2010). Human Anatomy and Physiology, (8th edition). San Francisco: Pearson Noble, D, & Hercheulz, A. (2007). Role of Na/Ca exchange and plasma membrane Ca2+-ATPase in cellular function. Na/Ca Exchange Conference, Vol. 8, n.3, pp. 228-232, accessed March 20, 2014, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1808037/Shane, E, and Dinaz, I (2006). Hypercalcemia: Pathogenesis, Clinical Manifestations, Differential Diagnosis, and Management, Department of Medicine, Columbia University, New York, viewed March 15, 2014, http://www.homepages.ucl.ac.uk/~ucgatma/Anat3048/PAPERS%20etc / ASBMR%20Primer%20Ed%206/Ch%2026-41%20-%20Disorders%20of%20Serum%20Minerals.pdfTamarkin, D (2011). Synapses, Springfield Technical Community College, Massachusetts, viewed March 18, 2014, http://faculty.stcc.edu/AandP/AP/AP1pages/nervssys/unit11/synapses.htm