Final answer:
Bone contains collagen fibers that provide a surface for inorganic salt crystals to adhere, including calcium carbonate. Calcium is an essential element that is stored in bones and teeth, with various functions in the body. Calcium ions are crucial for muscle contraction, enzyme activity, and other biological processes.
Step-by-step explanation:
Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide a surface for inorganic salt crystals to adhere.
These salt crystals form when calcium phosphate and calcium carbonate combine to create hydroxyapatite, which incorporates other inorganic salts like magnesium hydroxide, fluoride, and sulfate as it crystallizes, or calcifies, on the collagen fibers.
The hydroxyapatite crystals give bones their hardness and strength, while the collagen fibers give them flexibility so that they are not brittle.
Calcium is a chemical element that cannot be produced by any biological processes. The only way it can enter the body is through the diet.
The bones act as a storage site for calcium: The body deposits calcium in the bones when blood levels get too high, and it releases calcium when blood levels drop too low. This process is regulated by PTH, vitamin D, and calcitonin.
About two pounds of calcium in your body are bound up in bone, which provides hardness to the bone and serves as a mineral reserve for calcium and its salts for the rest of the tissues.
Teeth also have a high concentration of calcium within them. A little more than one-half of blood calcium is bound to proteins, leaving the rest in its ionized form. Calcium ions, Ca²+, are necessary for muscle contraction, enzyme activity, and blood coagulation.
In addition, calcium helps to stabilize cell membranes and is essential for the release of neurotransmitters from neurons and of hormones from endocrine glands.