Pathology of Calcium-Regulating Hormones (Jennings) Flashcards
What is the major role of the parathyroid gland?
Regulating serum Calcium and Phosphorus homeostasis via the production of the Parathyroid hormone (PTH)
The parathyroid glands have an interconnected relationship with other tissues and organ systems: namely, bone, the kidneys, and the intestine. Fill in the blanks:
Parathyroid hormone acts to indirectly stimulate ________resorption and_________ matrix breakdown via osteoclasts, thereby liberating calcium stored within ____________
bone
The parathyroid glands have an interconnected relationship with other tissues and organ systems: namely, bone, the kidneys, and the intestine. Fill in the blanks:
Parathyroid hormone directly stimulates calcium resorption by _____________________, as well as stimulating phosphorus secretion, thereby increasing serum calcium.
renal distal tubules
The parathyroid glands have an interconnected relationship with other tissues and organ systems: namely, bone, the kidneys, and the intestine. Fill in the blanks:
Parathyroid hormone indirectly facilitates intestinal calcium absorption by inducing the production of _________________ by renal tubular epithelium. ________________ then acts on the intestinal epithelium (enterocytes) to induce the transport of calcium from the intestinal lumen into the blood.
vitamin D3 (1,25 hydroxycholecalciferol)
What cells are responsible for the production and secretion of parathyroid hormone, which is stimulated by low blood calcium levels?
Chief cells
What are the major players with regard to calcium-regulating hormones in the body?
- Parathyroid hormones (PTH)
- Calcitriol (produced in the kidney, Vitamin D)
- Calcitonin
- FGF-23 (regulation of phosphorus and plasma)
(T/F) Calcium is utilized as a secondary messenger and at the cellular level, a lot of energy is utilized in order to maintain low levels of intracellular calcium that helps to facilitate the usage of calcium as a secondary messenger
True
What are the two sources of calcium?
- Diet (major source)
- Bone
(T/F) The calcium that is accessible is impacted by other things including the balance of calcium and phosphorus within the diet
True
Which is the first and the most readily available and accessible source that the body can draw calcium?
EXtracellular fluid calcium within the bone
What source of calcium is much less readily available and it requires osteoclasts to break down the bone in order to access it?
Hydroxyapatite crystals
What is a major site of calcium regulation?
Kidney
What is the function of vitamin D metabolism?
- Facilitates intestinal absorption of calcium (calcium-binding protein)
- Inhibits PTH synthesis and secretion by chief cells of the parathyroid
What are a couple of different causes for Vitamin D deficiency?
- Diets low in vitamin D
- UV-light-induced activation of vitamin D in the epidermis
- Sheep and South American camelids tend to be more susceptible to this than cattle
When talking about disorders of vitamin D metabolism, they can have phosphorus deficiency. And phosphorus is required for:
Extracellular formation of hydroxyapatite
What are the two major diseases of vitamin D?
Rickets and osteomalacia
(T/F) Osteomalacia is more commonly seen than rickets
False
Young animals at sites of endochondral ossification
Rickets