Parathyroid chief cell. Parathyroid chief cells (also called parathyroid principal cells or simply parathyroid cells) are cells in the parathyroid glands which produce parathyroid hormone. The end result of increased secretion by the chief cells of a parathyroid gland is an increase in the serum level of Calcium. Parathyroid chief cells constitute one of the few cell types of the body that regulate intracellular calcium levels as a consequence of extracellular (or serum) changes in calcium concentration.
According to the National Basketball Association, basketball courts should be rectangular shapes that are 94 feet long and 50 feet wide, with inner dimensions including a 23 foot, 9-inch semicircular three-point arc at either end of the court; however, dimensions for other leagues and age groups may differ.
The key, officially referred to as the free throw lane by the National Basketball Association and the National Collegiate Athletic Association, the restricted area by the international governing body FIBA, and colloquially as the lane or the paint, is a marked area on a basketball court surrounding the basket. It is bounded by the endline, the free-throw line and two side lines, and usually painted in a color different than the rest of the field. It is a critical area on the court where much of