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Flashcards in Parathyroid gland Deck (48):
1

when calcium is low in the blood, what does it bind to

Calcium sensitizing receptor on the parathyroid gland

2

when calcium binds to calcium sensitising receptor it causes what

release of PTH which causes increases calcium

3

Where is PTH absorbed

the gut

4

Where is PTH resorbed

bones

5

What is needed to promote Calcium absorption in the intestines

Vitamin D

6

what is vitamin D needed for

calcium absorption into intestines
bone resorption by increasing osteoclast number
to promote proper function of parathyroid gland

7

What are the symptoms of acute hypercalcaemia

thirst
dehydration
confusion
polyuria

8

what are the symptoms of chronic hypercalcaemia

myopathy
osteopenia
fractures
depression
abdominal pain - pancreatitis, ulcers, renal stones

9

What is the rhyme to remember the complications of chronic hypercalcaemia

stones, groans, bones, psychic moans

10

What is the investigation for hypercalcaemia

albumin - if low, check PTH
if PTH normal/high, check urine Calcium (if increased then either primary/tertiary hyperparathyroidism

11

what is the most common cause of hypercalcaemia

primary hyperparathyroidism

12

what are other causes of hypercalcaemia

malignancy
vitamin D supplements
thiazides
granulomatous diseases - sarcoidosis, TB
familial hypocalciuric hypercalcaemia

13

what would the biochemistry of granulomatous diseases causing hypercalcaemia look like

low PTH
high Ca

14

what would the biochemistry of familial hypocalciuric hypercalcaemia look like

normal/high PTH
low urine Ca
high serum Ca

15

What does the biochemistry of primary hyperparathyroidism look like

increased serum PTH
increased serum Ca
increased urine Ca

16

what does the biochemistry of malignancy causing hypercalcaemia look like

high serum Ca
increased Alk phos

17

what other investigations would be helpful for suspected malignancy in hypercalcaemia

X-ray
CT
MRI
isotope bone scan

18

what is the acute treatment for hypercalcaemia

IV fluids 0.9% saline
consider loop diuretics (decrease Ca reabsorption)
bisphosphonates (single dose will decrease Ca over 2-3 days)

19

What is the treatment for primary hyperparathyroidism

surgery/nothing (drugs don't work)

20

What are the indications for surgery in primary hyperparathyroidism

if organ damage
very high calcium (>2.85)
under 50yrs
eGFR <60l/min

21

primary hyperparathyroidism can be described as

overactivity of the parathyroid

22

what is the most common cause of primary hyperparathyroidism

adenoma

23

secondary hyperparathyroidism can be described as

physiological response to low calcium

24

what are the causes of secondary hyperparathyroidism

malnutrition (vitamin D deficiency)
chronic kidney disease

25

what does the biochem of secondary hyperparathyroidism look like

Ca decreased
PTH increased

26

What can tertiary hyperparathyroidism look like

occurs in a patient with a parathyroid after its been secondary for years
when it tries to go back to normal, it's already secreting too much PTH

27

What does the biochem of tertiary hyperparathyroidism look like

increased calcium
increased PTH

28

What is the inheritance of familial hypocalciuric hypercalcaemia

autosomal dominant

29

What is the mutation in hypocalciuric hypercalcaemia

deactivating mutation in calcium sensing receptor

30

Hypocalciuric hypercalcaemia is usually

benign/asymptomatic

31

What is the investigation for familial hypocalciuric hypercalcaemia

genetic screening

32

What are the symptoms of hypocalcaemia

paraesthesia - fingers, toes, peri-oral
muscle cramps, tetany
muscle weakness
fatigue
bronchospasm
fits
Chovstek's sign
Trousseau sign

33

What is chovstek's sign in hypocalcaemia

face will twitch when tapping over the facial nerve

34

what is trouseau's sign in hypocalcaemia

carpopedal spasm

35

what will be seen on ECG of someone with hypocalcaemia

QT prolongation

36

what are the causes of hypocalcaemia

hypoparathyroidism
Vit D deficiency
chronic renal failure

37

What is the treatment for acute hypocalcaemia

IV calcium gluconate - 10ml 10% over 10min (dissolved in 50ml saline/dextrose)

38

What are the causes of hypoparathyroidism

DiGeorge syndrome
Destruction - surgery, radiotherapy, malignancy
autoimmune
hypomagnesaemia
idiopathic

39

why does DiGeorge syndrome cause hypoparathyroidism

they have no parathyroid glands

40

What is the long term management of hypoparathyroidism

Calcium supplements
vitamin D supplements - 1alpha calcidol (tablet), cholecalciferol (injection)

41

Calcium release from cells is dependent on magnesium. If magnesium is decreased, what happens to intracellular Calcium

increases

42

If intracellular calcium increases, what happens to PTH

decreases

43

What is the treatment for hypomagnesaemia

magnesium and calcium replacement

44

what are the causes of hypomagnesaemia

alcohol
thiazides
PPIs
GI illness
pancreatitis
malabsorption

45

Pseudohypoparathyroidism is caused by a genetic defect in what

GNAS1

46

What does the biochem look like in pseudohypoparathyroidism

decreased Calcium
increased PTH (due to PTH resistance)

47

What are the complications of pseudohypoparathyroidism

bone abnormalities (McCune Albright)
obesity
subcutaneous calcification
learning disability
brachdactylyl (loss of 4th metacarpal)

48

Chronic renal disease can cause vitamin D deficiency which leads to secondary hyperparathyroidism. what might be seen on investigation

increased 25-OH vitamin D