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.
The parathyroid glands are four tiny glands, located in the neck, that control the body's calcium levels. Each gland is about the size of a grain of rice (weighs approximately 30 milligrams and is 3-4 millimeters in diameter). The parathyroids produce a hormone called parathyroid hormone (PTH). PTHPTH - parathyroid hormone raises the blood calcium level by: breaking down the bone (where most of the body's calcium is stored) and causing calcium release. increasing the body's ability to absorb calcium from food.
3 years ago. Parathyroid hormone and calcitonin are antagonistic hormones, which are released in response to blood calcium levels. In other words, PTH acts on the same target organs as calcitonin, but produces the opposite effects.Parathyroid hormone is released from the parathyroid glands, and calcitonin is released from the thyroid gland. If blood calcium concentration is high, calcitonin is released.arathyroid hormone is released from the parathyroid glands, and calcitonin is released from the thyroid gland. If blood calcium concentration is high, calcitonin is released.