calcium

Question 1

99% of calcium is stored in the ?

Answer 1

bone

Question 2

is calcium soluble?

Answer 2

in blood no, but with phosphate it is calcifying

Question 3

concentration of calcium is very

Answer 3

fixed in blood

Question 4

free ionised calicum

Answer 4

50%

Question 5

protein bound calcium?

Answer 5

40% - albumin

Question 6

complexed calcium citrate / phosphate

Answer 6

10%

Question 7

range of calcium

Answer 7

2.2-2.6 mmol/l

Question 8

why is calcium levels important?

Answer 8

muscle depolarisation and so in control of nerve and muscle

Question 9

corrected ca2?

Answer 9

40g/L is albumin
+0.02
because difference is 10

Question 10

if albumin is low then the serum ca2 is much higher

Answer 10

true

Question 11

low albumin occurs in what type of patients?

Answer 11

very sick, septic
liver is failing or kidneys are losing albumin

Question 12

why correct?

Answer 12

because calcium can be normal but due to low albumin it comes out normal

Question 13

why is concentration of calcium important

Answer 13

normal nerve and muscle fucntion

Question 14

pth obtains ca2 from 3 places?

Answer 14

bone
gut absorption
kidney - resorption and r1alpha hydroxylase activation

Question 15

rate limiting step for ca2

Answer 15

renal 1 alpha hydroxylase

Question 16

PTH

Answer 16

is a protein from parathyroid glands (except in cancer)

Question 17

pth

Answer 17

phosphate thrashing hormone

Question 18

cholecalciferol is stored?
what happens here?

Answer 18

liver
hydroxylates it

Question 19

kidney will only activate vit d when?

Answer 19

PTH is released so when ca2 is low

Question 20

what is calcetriol?

Answer 20

1,25 (OH)2 D3
physiologically active form

Question 21

ergocalciferol is a plant product

Answer 21

true

Question 22

sarcoidosis

Answer 22

activates vit D
can become hypercalcaemic
ectopic expression of 1 alpha hydroxylase

Question 23

25 hydroxylase is found in which organ?

Answer 23

liver

Question 24

1 alpha hydroxylase is found?

Answer 24

kidney

Question 25

high alkaline phosphatase

Answer 25

bone issue - osteomalacia so if raised only AFP it is a bone issue not a liver issue

Question 26

loosers zone

Answer 26

pseudo fractures

Question 27

rickets signs

Answer 27

bowed legs costochondral swelling widened epihphyses at wrists myopathy

Question 28

the difference between osteoporosis and osteomalacia?

Answer 28

loss of bone but with a normal calcium, normal phosphate osteomalacia inadequate mineralization of bone tissue abnormal ca2+

Question 29

calcium falls. what happens?

Answer 29

PTH levels rise osteoblast act and break bone to release ca2+ phosphate is excreted in urine so phosphate falls

Question 30

DEXA score T score

Answer 30

dual energy xray absorptiometry T-score is the sd from mean of young healthy population

Question 31

z score

Answer 31

sd from mean of aged matched control

Question 32

osteoporosis osteopenia T score difference?

Answer 32

<-2.5 -1- -2.5

Question 33

mx osteoporosis

Answer 33

vit D/ca2+ bisphosphonates teriparatide strontium, anabolic and anti-resorptive oestrogems SERMs (raloxifene

Question 34

why do bisphosphonates help in osteoporosis

Answer 34

alendronate (swallow with water, by itself and wait) osteoclasts uses it make bone and it makes strong bones zolendronate peptic ulcers is a complication

Question 35

hypercalcaemia symptoms

Question 36

hypercalcaemia ix?

Answer 36

check again PTH

Question 37

is PTH suppressed in hypercalcaemia if yes what is the cause? if no what is the cause?

Answer 37

PTh suppressed - malignanct (most common) sarcoid, vit D, thyrotoxicosis primary hyperparathyroidism (problem with PTH regulation primary) familial hypocalciuric hypercalcaemia

Question 38

commonenst cause of hypercalcaemia?

Answer 38

primary hyperthyroidism parathyroid adenoma, hyperplasia, carcinoma hyperplasia associated with MEN1 women>men bones(fractures) , stones, abdo moans, psychiatric groans

Question 39

hypercalcaemia malignant causes?

Answer 39

humoral hypercalcaemia of malignancy small cell lung Ca2+ PTHrP bone metastases myeloma (haematological malignancy) due to cytokines

Question 40

other causes of non-PTH driven hypercalcaemia

Answer 40

sarcoidosis (non-renal 1a hydroxylation) thryotoxicosis hypoadrenalism thiazide diuretics excess vit D

Question 41

how to manage hypercalcaemia?

Answer 41

Fluids because they are severely dehydrated - bisphosphonates 9if cancer) treat underlying cause

Question 42

hypocalcaemia causes ____musucluar excitibility

Answer 42

neuromuscular excitiability chovstek sign trousseaus sign

Question 43

hypocalcaemia PTh low causes

Answer 43

can be due to low albumin surgical (thyroidectomy) congenital absence of parathyroids - DiGeogre auto-immune hypoparathyroidism

Question 44

non pth causes of hypocalcaemia?

Answer 44

lack of vit D ckd - 1a hydroxylation pseudohypoparathyroidism - body is not sensitive to pth

Question 45

tertiary hyperpara

Answer 45

had secondary for a long time

Question 46

pagets disease

Answer 46

focal disorder of bone remodeling radioactive bisphosphonate elevated ALP