Final answer:
The human skeleton does contain calcium atoms, primarily in the form of hydroxyapatite and calcium phosphate, which are essential for bone mineralization, structure, and strength.
Step-by-step explanation:
The statement that calcium atoms are not present in a human skeleton is incorrect. Calcium is not only the most abundant mineral in bone, it is in fact the most abundant mineral in the human body. Calcium ions play a crucial role not only in bone mineralization but are also essential for tooth health, the regulation of the heart rate and the strength of muscle contractions, blood coagulation, nerve impulse conduction, and the contraction of both smooth and skeletal muscle cells.
The bones act as a storage site for calcium, keeping the normal level of calcium in the blood at about 10 mg/dL. To maintain proper health, the human diet must provide a regular supply of calcium as the body cannot produce it by itself. When blood levels are too high, the body deposits calcium in the bones, and when they drop too low, it releases calcium into the bloodstream, with this balance being regulated by parathyroid hormone (PTH), vitamin D, and calcitonin.
Bone itself contains a small number of cells within a matrix of collagen fibers. These fibers provide the structure for inorganic salt crystals, primarily hydroxyapatite, composed of calcium phosphate and calcium carbonate, which are what give bones their hardness and strength. The presence of calcium in the form of hydroxyapatite and calcium phosphate constitutes about 99% of the total calcium within the body, emphasizing the importance of this mineral in skeletal health.