Rock is considered an ecosystem because based on the definition of ecosystem. A rock is happens to be in our environment which makes it part of our ecosystem. 1 person found this useful.
Parathyroid hormone. Parathyroid hormone (PTH), also called parathormone or parathyrin, is a hormone secreted by the parathyroid glands that is important in bone remodeling, which is an ongoing process in which bone tissue is alternately resorbed and rebuilt over time. It essentially increases blood calcium levels.
Parathyroid glands. The parathyroid glands are located on the posterior of the thyroid gland. The parathyroid glands produce parathyroid hormone (PTH) which increases blood calcium concentrations when calcium ion levels fall below normal. One of the parathyroid glands' most important functions is to regulate the body's calcium and phosphorus levels.