L15: Calcium and Parathyroid gland Flashcards
Where is the parathyroid gland located
On the thyroid glands
What hormone does the parathyroid hormone secrete
PTH
What type of hormone is PTH
Peptide
When does PTH secrete
In low calcium
When does vitamin d come into hand
In low calcium
Where does vitamin D act on
The intestines:
- increases calcium and phosphate absorption
Where does PTH act on
GCPRs on the kidney
What hormone is secrete in high calcium
Calcitonin
Where is calcitonin produced
In the c-cells of thyroid glands
Where does calcitonin act on
The bones to decrease calcium absorption.
What hormone is released when there is high potassium
FGF23
Where is FGF23 made
In the bone cells
Where does FGF23 act on
The kidney to increase urinary phosphate
What are the levels of 1,25D3 in hypophosphataemia
Low so that it does not bring in phosphate from the intestine
What other hormone is involved in high levels of phosphate
PTH so urinary phosphate increases
Which cell crushes the bone
Osteoclasts
Which cell builds the bone
Osteoblasts
What is hyperparathyroidisim
High levels of PTH levels
What is primary Hyperparathryoidism
Tumour in the parathyroid gland. It is usually a benign adenoma
Why is primary HPT caused
Parathyroid gland does not react to the negative feedback
What is secondary HPT
Renal disease:
- kidney stops functioning so phosphate increases and 1,25D3 decreases
What is tertiary HPT
Prolonged state of tertiary HPT
What is rickets
Lack of mineralisation of bone due to low VD3
What is the treatment of rickets
Vitamin D replacement
What is osteomalacia
Same as rickets but occurs in adults
What group of people does rickets occur in
Children
What is osteoporosis
Loss of mineral and collagen component
What is the treatment of osteoporosis
PTH
Oestrogen
Denosumab
Bisphosphatase
What causes the production of 1,25D3
PTH
Where is 1,25D3 made
In the kidney
What does secondary hyperparathyroidism lead to
Chronic kidney disease mineral and bone disorder
What does renal disease give for hyperparathyroidism to occur
Hypocalcemia
Hyperphosphotemia
These factors lead to the increase of PTH from the parathyroid gland
Why does osteoporosis increase in woman after menopause
Estrogen levels decline which lead to increased levels of bone remodelling and bone resorption so mineral is lost.
In rickets is collagen also lost from the bone
No collagen is not lost, only mineral ( phosphate and calcium) are lost
