Endocrine is the type of long distance intercellular communication to which hormones like parathyroid hormone falls into.
An endocrine intercellular communication is the most common type of cell signaling. It primarily involves sending a signal throughout the whole body through hormonal secretion into the bloodstream.
The human body has four parathyroid glands. These are butterfly shaped and are located inside the neck, more specifically on both sides of the windpipe or larynx. One of its most important functions is to regulate the body's calcium and phosphorous levels. It also secretes the parathyroid hormone.
PTH is secreted from the four glands. It is released directly into the bloodstream which means it needs to travel to its target cells which are often far away. This is the reason why it needs intercellular communication to reach its destination.