Endocrine System

The endocrine system is a very important control system in the network of the human body. It works closely with the nervous system to carry out the necessary tasks required to keep our bodies working on a daily basis. The endocrine system uses ductless glands to send hormones traveling throughout the bloodstream to be transported for delivery to their target. We will explore this process further to understand the importance of this system, and what happens when it doesn’t work as designed. (Marieb & Hoehn, 2007)

One of the major glands of the endocrine system is the parathyroid gland. The average human body has four parathyroid glands, but can have fewer or more glands. They contain oxyphil cells and many chief cells. The chief cells secrete parathormone, or PTH. It’s hard to believe that in this day and age, we don’t exactly know what the function of the oxyphil cells are. PTH is essential to calcium balance in the blood. When PTH is released, osteoclasts digest some of the bony matrix and send ionic calcium and phosphates into the bloodstream. The kidneys metabolize and pass on their waste. PTH stimulates the kidneys to transform inactive forms of vitamin D into an active form, called calcitriol. The PTH’s role in activation of vitamin D is considered indirect. This entire process is important because it promotes a rise in calcium levels in the bloodstream, by the coordinated effects of the exchange of calcium and phosphate from the bone, the calcium re-absorption and vitamin D activation of the kidneys, and finally the calcium absorption of the intestine. The levels of calcium must be balanced in order to maintain homeostasis. (Marieb & Hoehn, 2007)

An example of a homeostatic imbalance would be a patient named Mr. Sanchez, who makes an appointment to see his doctor for pain in his abdominal area. Tests and x-rays reveal kidney stones as well as bones with a moth-eaten appearance. Further questioning reveals a medical history of abdominal reflexes and...