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.
1 Thyroxine (T4) is the key hormone produced in the thyroid gland. 2  Low levels of T4 produce hypothyroidism, and high levels produce hyperthyroidism. 3  Thyroxine converts to triiodothyronine (T3), which is a more biologically active hormone.4  Only about 20% of triiodothyronine is actually formed in the thyroid gland. Thyroxine (T4) is the key hormone produced in the thyroid gland. 2  Low levels of T4 produce hypothyroidism, and high levels produce hyperthyroidism. 3  Thyroxine converts to triiodothyronine (T3), which is a more biologically active hormone.