Alyssa Foels
12 February 2015
Kilfe
Calcium is a cation, a positively charged atom, and it is essential to all living things. It was first discovered in 1808 by Humphrey Davy. When forming an ionic bond with other elements, calcium loses electrons to make its valence shell stable. This means that it has more protons than electrons, making it have a slight positive charge (Calcium).
Calcium has many roles and functions in the human body. Calcium ions are the most abundant mineral in the composition of bones and teeth. Approximately ninety-nine percent of all calcium in the human body is contained in the teeth and bones (Edwards, 58). The remaining calcium is stored in the plasma in two forms: ionized and non-ionized. Non-ionized calcium is bound to proteins (not diffusible through capillaries) or anions (diffusible through capillaries), whereas ionized calcium is free and is found in the heart, central nervous system, and bones (Regulation of Calcium and Phosphate Levels in the Body).
Although only about one percent of calcium in the human body is found outside of the bones and teeth, it has an essential role in many body metabolic functions and processes. Calcium is not only used in the structure of bones and teeth, but it is required in many other body functions including, but not limited to, cardiac action potentials, the contraction of cardiac, skeletal and smooth muscle, blood clotting, and the transmission of neural impulses (Edwards, 58).
Calcium ions are necessary in the process of muscle contraction. When muscles contract, the constituent fibers shorten. The nerve impulses which lead to the contractions, or shortening of these fibers, cause an increase in calcium ion concentration in muscle cells. When a muscle is at rest, the concentration of calcium ions in the muscle cells is low due to the constant activity of the calcium pump. The calcium pump channels calcium ions between the intracellular matrix and the
Cited: Edwards, S. (2005, May 10). Maintaining calcium balance: Physiology and implications. Nursing Times, 58-58. Calcium. (n.d.). Retrieved February 13, 2015, from http://www.rsc.org/periodic- table/element/20/calcium Hemostasis. (n.d.). Retrieved February 13, 2015, from http://howmed.net/physiology/hemostasis/ Regulation of Calcium and Phosphate Levels in the Body. (n.d.). Retrieved February 13, 2015, from http://howmed.net/physiology/regulation-calcium-phosphate/