Dr. Cortisan, Oscar Porosis’ doctor, showed him the x-rays, and immediately knew why he was in so much pain--his bones were a mess. Dr. Cortisan explained to him that his soft, decalcified, porous bones were not due to a vitamin D deficiency, but rather, to a severely inadequate calcium diet. Oscar has heard from some of his female relatives that decalcified, deteriorating bones were due either to vitamin D deficiency, or menopause. Menopause?! But then Oscar remembered hearing that men don’t have menopause. It suddenly dawned on him that Dr. Cortisan calling him a woman? Oscar was insulted and suspicious. To make matters worst, the doctor gave him a copy of the blood results. To his horror, his suspicions were confirmed!
The blood test showed that his calcium levels were with normal range, his vitamin D levels were within normal range, and the only substance that was elevated was something called parathyroid hormone (PTH).
A mostly confused, but very livid Oscar, decided then and there, that Dr. Cortisan is a quack and should be reported to the authorities! However, Oscar knows that you are studying the Endocrine system and has asked for your help to formulate is complaint.
Based on your knowledge of the endocrine system, hormone regulation, calcium homeostasis and feedback loops
Explain to Oscar:
(a) What exactly is PTH
(b) How an elevated level of PTH may help to explain the calcium paradox that Oscar is seeing in his test results (the ones that have convinced Oscar that his doctor is a quack ).
Please do not confuse Oscar any further, and keep in mind that Dr. Cortisan’s