Parathyroid Pathology Flashcards
Name the cells types in the parathyroid gland
chief cells -> secrete PTH
oxyphil cells
What does PTH do ?
involved in increasing total body calcium, alongside calcitriol (vitamin D)
What does calcitonin do ?
involved in decreasing total body calcium (effects bone and kidneys)
What causes hypercalcaemia ?
hyperparathyroidism
Addison’s disease
renal disease
Vit D toxicosis
idiopathic
osteolytic
neoplastic
spurious
granulomatous
Hypoparathyroidism definition and causes
Decreased action of the parathyroid gland
- idiopathic hypoparathyroidism
- surgical removal or trauma
- destruction related to local inflammation or tumours
- trophic atrophy
Main clinical consequence of hypoparathyroidism
hypocalcaemia
resulting in excessive neuromuscular excitability (tetany or paresis), commonly called phosphorous
Hyperparathyroidism definition and common causes
increased action of the parathyroid gland
- primary (adenoma, hyperplasia, carcinoma)
- secondary (renal or nutritional)
- pseudo (humoral hypercalcaemia of malignancy)
Main clinical consequence of hyperparathyroidism
Hypercalcaemia
(vomiting, anorexia, PU/PD, urolithiasis, muscle weakness/lethargy, fibrous osetodystrophy)
Primary hyperparathyroidism causes
multinodular hyperplasia
adenomas
to note, blood work will have hypercalcaemia
Secondary hyperparathyroidism causes
nutritional (deficient calcium, Vit D or excess phosphorous) REPTILES !!
renal (phosphate retention and decreased glomerular filtration rate)
Define pseudohyperparathyroidism
humoral hypercalcaemia of malignancy (HHM)
certain tumours secrete PTH-like peptide called PTHrp, which has similar physiological effects as PTH
Parturient Hypocalcaemia definition
“Milk fever”
hypocalcaemia and hypophosphatemia near parturition due to an increased demand for Ca2+ and phosphorous
in cows, results in paresis (“downer cow”)
in dogs, results in tetany (muscle spasms, owners report as seizures)
