Put simply, volume refers to the number of contracts traded. For any trade to occur, the market needs to produce a buyer and a seller. A transaction occurs when buyers and sellers meet and is referred to as the market price.
This hormone is secreted from cells of the parathyroid glands and finds its major target cells in bone and kidney. Another hormone, parathyroid hormone-related protein, binds to the same receptor as parathyroid hormone and has major effects on development.
The sole purpose of the parathyroid glands is to control calcium within the blood in a very tight range between 8.5 and 10.5. In doing so, parathyroid glands also control how much calcium is in the bones, and therefore, how strong and dense the bones are.hen the calcium level in the blood is too low, the cells of the parathyroids sense it and make more parathyroid hormone. Once the parathyroid hormone is released into the blood, it circulates to act in a number of places to increase the amount of calcium in the blood (like removing calcium from bones).