Endo 6 - Calcium Flashcards Preview

HD3 Endocrine > Endo 6 - Calcium > Flashcards

Flashcards in Endo 6 - Calcium Deck (53):
1

Is there more Ca in ICF or ECF

ICF

2

can Ca and PO4 be regulated separately

NO

3

Ca x PO4 = ?

constant

4

where does most calcium come from

our bones

5

what % of ca do we absorb in diet

15-35%

6

what type of hormone is vitamin D

steroid

7

what is stimulated when vitD binds receptor

calcium binding protein synthesis

8

what is the function of calcium binding protein

allows ca to cross intestines and enter blood

9

how does vitD binding affect differentiation

increases diff and maturation

10

how is PO4 affected by vitD active

increase intestinal absorption

11

how are kidneys affected by vitD

increase ca reabsorption

12

how are osteoclasts affected by vitD

increase # of osteoclasts

13

how are muscles affeted by vitD

more strength

14

why are younger people better at making vitD

thicker skin = more vitD precursor = more rxn

15

what is storage form of vitD

25-vitD

16

what enzyme makes vitD active

1a-hydroxylase

17

what are 4 ca-regulating hormones

PTH, PTHrP, calcitonin, vitD

18

T/F PTH is constantly made and stored in parathyroid

TRUE

19

what causes increase in PTH secretion

low serum Ca => activate Ca sensor in parathy => PTH secretion

20

what is the mechanism of PTH action

GPCR => AC => cAMP

21

how does PTH affect immature osteoblasts

binds to young osteob to stim and form osteocl

22

where are PTH receptors in the kidney

distal tubule

23

what happens to PO4 in response to PTH

PO4 is kicked out

24

T/F high PO4 can stimulate PTH

TRUE

25

what is the main difference between PTH and PTHrP

no activation of vitD

26

what are PTH levels when PTHrP is present

low - high calcium neg feedback

27

where are receptors for calcitonin

osteoclasts

28

osteoclast + calcitonin =

shriveled up osteoclast

29

what does calcitonin do

decreases osteoclast activity, briefly lowers serum ca

30

what are 2 reasons for hypercalcemia

too much PTH/vitD or too much PTHrP

31

2 reasons for hypoca

too little PTH/VitD or resistance to Ca/vitD

32

how does hyperca affect axons

decreases AP firing/neuromusc excitability

33

signs/symptoms of hyperca

stones, groans, moans, overtones, bones, HTN

34

what causes high PTH

parathy adenoma
parathy hyperplasia
MEN

35

what causes high vitD

ingestion
granulomatous disease

36

what are 2 general causes of hypercalcemia

tumor secreting PTHrP
lymphoma/leukemia causing active vitD

37

high vitD = what for ca, phos, 1,25vitD, PTH

high high low low

38

PTHrP = ca, phos, 1,25, PTH

high low normal low

39

HPT = serum values

high low high high

40

how does hypoca affect neurons

increase excitability

41

cvostek's sign =

facial muscle contraction

42

trousseau sign =

carpal spasm

43

how does hypoca affect QT interval

prolongs QT

44

3 causes of PTH deficiency

surgery
autoimmune
congenital abnormality

45

low PTH =

low Ca, high phos, low vitDactive

46

childhood vitD deficiency =

rickets

47

what happens to cartilage and bone in rickets

excess cartilage and unmineralized bone

48

what is damaged to preserve serum Ca in mild adult vitD deficiency

bones

49

severe adult vitD def =

osteomalacia

50

what bone path is found in osteomalacia

osteoids (unmin protein matrix)

51

primary hyperparathy =

high PTH => high ca

52

secondary hyperparathy =

low Ca => high PTH (vitD def or kidney fail)

53

kidney failure affects PO4 and ca how?

raises serum PO4 and drops serum ca => high PTH