Kinder, bone mineral homeostasis part I Flashcards Preview

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Flashcards in Kinder, bone mineral homeostasis part I Deck (47):
1

what minerals are used for bone homeostasis

Ca
phosphate

2

what hormones are used for bone homeostasis

teriparatide (forteo)
calcintonin (fortical)

3

what are the drugs we have that are vit D, metabolites and analogs

cholecalciferol (Vit D3)
ergocalciferol (Vit D2)
calcitriol

4

drug that is selective estrogen R modulator

raloxifene (Evista)

5

what bisphosphonate do we use

alendronate (fosamax)

6

where is most cortical bone

appendicular or peripheral bone

7

where is trabecular bone

acial or central (spine and pelvis)

8

what regulate osteoclast production

osteoblast derived cyrokines

9

What is RANK

R for NK-kbeta that is an osteoclast protein required for osteoclastic bone resorption

10

osteopblasts produce what to keep osteoclast under regulation

osteoprotegerin which acts as a decoy ligand for RANKL

11

when is OPG suppressed

increased bone resorption
e.g. estrogen deprivation

12

how long does remodeling of one take

6 mo

13

where is Ca absorbed

duodenum and upper jejunum

14

what is absorbed more, Ca or PO4

PO4

15

where is filtered Ca resorbed

kidney

16

extracell Ca and PO4 levels

Ca 8.5-10.4
PO4 2.5-4.5

17

how does PTH change Ca and PO4 levels

increased serum Ca and decreased serum PO4

18

how does PTH increase osteoclasts

induces osteoblasts to secrete RANKL

19

PTH inhibits production of what from osteocytes

sclerostin which blocks osteoblast proliferation

20

PTH affect on kidney

PTH increases tubular reabsorption of Ca and inhibits reabsorption of PO4

21

PTH increases excretion of what

amino acids, bicarb, Na, Cl, and sulfate

22

Ca changes PTH how

decrease PTH production

23

what is teriparatide

synthetic recombinant human PTH

24

MOA teriparatide

continuous administration of PTH caues bone demineralization and osteopenia
intermittent PTH promotes bone growth

25

therapeutic use teriparatide

women with Hx osteoporosis who have multiple risk factors for fracture, or who have failed other therapy
men with primary hypogonadal osteoporosis

26

adverse effects teriparatide

orthostatic HTN, hyper Ca, dizziness, nausea, hyperuricemia, angina

27

CI teriparatide

those at increased risk osteosarcoma, like Pagets or elevated alkaline phosphatase levels, open epiphyses or prior radiation therapy of skeleton

28

How is Vit D3 formed to active 1,25 dihydroxy vit D3

ultraviolet light on skin
then hydrozylation in liver and then in kidney

29

how does calicitriol increase bone turnover

promotes recruitment of soteoclast precursor cells to resorption sites
promotes development of mature osteoclasts
induce synthesis of several proteins that regulate bone mineralization process such as RANK ligand and osteocalcin

30

how do Vit D analogs work

increase intestinal absorption of Ca and PO4 as well as bone turnover

31

therapeutic use of vit D analogs

prophylaxis and cure of nutrional rickets
Tx metabolic ricketts and osteomalacia
Tx hypoPTH
prevention and Tx osteoporosis

32

what do ergocalcigerol or cholecalciferol require

metaboilc conversion in liver and kidney

33

what to give patient with liver disease and rickets or osteomalacia

25, hydroxyvit D because does not require hepatic hydroxylation

34

why is calcitriol used in patients with kidney disease

most rapid onset

35

what to watch when patient is on calcitriol

hypercalcemia

36

adverse effects to Vit D analogs

hyperCa, sometimes hyperPO4, nausea, vomiting, constipation
arrhythmias and pancreatitis

37

how does FGF-23 affect Ca and PO4 regulation

inhibits 1,25 OHvit D production and PO4 reabsorption in kidney

38

how does PTH change intestinal Ca and PO4

increased Ca and PO4 absorption
increased 1,25 OH production

39

how does PTH affect kidney excretion of minerals

dec Ca excretion
increased PO4

40

Vit D affects on intestine

increased Ca and PO4 absorption

41

Vit D affects on kidney

Ca and PO4 excretion

42

FGF23 affects on intestine

dec Ca and PO4 absorption

43

FGF23 affects on kidney

increased PO4 excretion

44

PTH affects on bone

Ca and PO4 resorption increased by high doses, low doses may increase bone formation

45

Vit D affects on bone

increased Ca and PO4 resorption by 1,25 OH Vit D,

46

FGF23 affects on bone

dec mineralization from hypoPO4

47

serum levels from:
-PTH
-Vit D
-FGF23

PTH: increased serum Ca decreased serum PO4
VitD: increased serum Ca and PO4
FGF23: decreased serum PO4