Final answer:
Calcium homeostasis, essential for many biological processes, involves the skeletal, endocrine, digestive, and urinary systems to maintain a normal blood calcium level of about 10 mg/dL. These systems work in synergy to store, absorb, regulate, and excrete calcium as needed to keep blood levels in check.
Step-by-step explanation:
Major Sites of Calcium Homeostasis
Calcium homeostasis is crucial for various body functions such as muscle contraction, nerve impulse transmission, and blood coagulation. The regulation of calcium levels in the body involves a complex interaction between different organ systems, with a normal blood calcium level being about 10 mg/dL. The skeletal system functions as a storehouse for calcium, depositing calcium when levels in the blood are high and releasing it when they fall. The endocrine system also plays a pivotal role through hormones like parathyroid hormone (PTH), vitamin D, and calcitonin.
The digestive system is involved as it aids in the absorption of calcium from our diet into the bloodstream. Lastly, the kidneys help in maintaining calcium balance by filtering excess calcium and aiding in its reabsorption. Pathologies such as hypocalcemia and hypercalcemia illustrate the necessity of regulating blood calcium levels for health and highlight the significance of these interconnected systems in maintaining calcium homeostasis.