Calcium Control Flashcards
where is most of the body’s calcium stored
in the skeleton as hydroxyapatite crystals
what cells produce PTH
chief cells in the parathyroid gland
what cells are found in the parathyroid gland
oxyphil cells and chief cells
what does PTH do
bone - increases osteoclast activity
kidneys - increase calcium reabsorption and phosphate loss
gut - activates vitamin D
this all causes an increase in serum calcium
what happens to activate vitamin D
it is hydroxylated in the kidney to produce calcitriol
what does cacitrol do
bone- osteoclast activity
kidneys - calcium reabsorption
gut - increases calcum binding protein so more calcium is taken up
these all increase serum calcium levels
what is calcitonin
hormone produced by parafollicular cells in the thyroid gland which decrease serum calcium
what symptoms are seen in hypocalcaemia
tingling and tetany in the hands and mouth, carpopedal spasm
what is primary hyperparathyroidism
when you have a PTH secreting adenoma
what is secondary hyperparathyroidism
where either a vit D deficiency (osteomalacia) or kidney failure (renal osteodystrophy) causes the glands to be hyperplastic
what are the symptoms of hypercalamia
moans - tired, depressed
bones - muscle and bone aching
groans - constipation, ulcers and pancreatitis)
stones - kidney stones
why do you get tingling and tetany in hypocalaemia
as calcium causes neural excitability
which types of cancer can metastasise to the bone and break it down
breast, lung, thyroid and renal
which types of cancer can metastasise to the bone and produce more bone
prostrate cancer
why can squamous tumours cause hypercalaemia
as they produce parathyroid hormone related peptide which acts on the parathyroid receptors
