Calcium Homeostasis


?
  • Created by: emma
  • Created on: 09-12-13 14:18
Hypocalcium increases nerve excitability.. leading to
tetany --> asphyxiation
1 of 24
Hypercalcaemia decreases neurotransmitter excitability... leading to
cardiac arrhythmias, lethargy, death
2 of 24
3 causes of hypercalcaemia
54% hyperthyroidism, 34% malignancy associated, 12% other
3 of 24
3 ways homeostasis is maintained
Bone - 500mg. Kidney, 10.8 filtration, 10.6 reabsorption. Intestines, 1g diet, 800mg faeces.
4 of 24
Free ionised calcium = ?mM
1.2 mM
5 of 24
sensing mechanisms sense changes in...
Free ionised calcium levels
6 of 24
Where is PTH produced
Chief cells in Parathyroid gland
7 of 24
Where is PTH cleaved
Liver
8 of 24
PTH secretion is ? proportional to serum calcium
inversely - signmoidal
9 of 24
Effects of VitD
increase net intestinal Ca uptake from 200-600 mg/day, increase calbindin expression, increase serum Ca levels by increased bone resorption and renal reabsorption
10 of 24
Deficiency of Vit D can cause
Rickets, secondary HPT and osteomalacia
11 of 24
Where is calcitonin produced
parafollicular thyroidal c cells
12 of 24
what calcitonin do?
decrease calcium after load
13 of 24
Oral calcium salts are..
calcium gluconate, calcium lactate, hydroxyapatite
14 of 24
injected calcium salts are
calcium gluconate for hypocalcaemia tetany
15 of 24
Oral vitamin D3...
t1/2=22hours, binds alpha globulin, treats rickets, osteodystrophy and HPT hypocalcaemia
16 of 24
Excess VitD3 can cause
hypercalcaemia, osteoporosis, proteinuria, polyuria, nephrocalcinosis, vascular cacification
17 of 24
To treat hypercalcaemic crisis..
saline hydration, furosemide (Lasix) diuresis (Decrease calcium reabsorption in cTAL), calcitonin (decrease bone resorption) and bisphosphonates
18 of 24
Glucocorticoid treatment
decreases intestinal ca absorption, decreases bone foration, increases renal extretion, may lead to osteoporosis
19 of 24
disphosphonates
decrease bone turnover, bind hydroxyapatite
20 of 24
mithramycin
decrease bone reabsorption, antibiotic in cancer treatment, treat hypercalcaemia and paget's at 1/10 of chemo dose
21 of 24
calcimimetics
decreases PTH secretion, treats primary and secondary HPT, +VE allosteric modulator of CR
22 of 24
calcilytics
increase PTH secretion, osteoporosis treatment, -ve allosteric modulator of CR (antagonist)
23 of 24
sodium cellulose phosphate
oral, binds ca in gut, decreases intestinal absorption, may increase serum phosphate
24 of 24

Other cards in this set

Card 2

Front

Hypercalcaemia decreases neurotransmitter excitability... leading to

Back

cardiac arrhythmias, lethargy, death

Card 3

Front

3 causes of hypercalcaemia

Back

Preview of the front of card 3

Card 4

Front

3 ways homeostasis is maintained

Back

Preview of the front of card 4

Card 5

Front

Free ionised calcium = ?mM

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Endocrinology resources »