Hyperparathyroidism Flashcards
How many parathyroid glands are there?
4 corners of thyroid gland
What cells produce PTH?
Chief cells in response to hypocalcaemia
PTH acts to do what?
Raises blood calcium
How does PTH act to raise blood calcium?
- Increased osteoclast activity in bones (reabsorbing Ca from bone)
- Increased calcium absorption from gut
- Increased calcium absorption from kidneys
- Increased vitamin D activity
What is primary hyperparathyroidism caused by?
Uncontrolled PTH produced directly by tumour of Parathyroid glands
Leads to hypercalcaemia
Treatment of primary hyperparathyroidism?
Surgically removing tumour
What is secondary hyperparathyroidism?
Where insufficient Vit D or chronic renal failure leads to low absorption of Ca form intestine, kidneys & bones
This causes hypocalcaemia
Parathyroid gland reacts to low serum Ca by excreting more PTH
Overtime number of cells in PT gland increased as they respond to increased need to produce PTH- hyperplasia
Serum Ca will be low/normal but PTH high
Treatment with secondary hyperparathyroidism?
Treat by correcting Vitamin D deficiency or performing renal transplant for renal issues
What is tertiary hyperparathyroidism?
When secondary hyperparathyroidism continues for long period of time, leads to hyperplasia of glands
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Baseline level of PTH increases dramatically
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When cause of secondary HPTism is treated the PTH remains inappropriately high
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Leading to inappropriately increased calcium absorption in intestines, kidneys & bones = Hypercalcaemia
Treatment of tertiary hyperparathyroidism?
Surgically by removing part of Parathyroid tissue to return the PTH level to normal
Cause, PTH and calcium levels of primary hyperparathyroidism?
Tumour
High
High
Causes, PTH and calcium levels of secondary hyperparathyroidism?
Low vitamin D or CKD
High
Low/normal
Causes, PTH and calcium of tertiary hyperparathyroidism?
Hyperplasia
High
High
