Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PHA223 > bone disorders/osteoporosis (Praveen) > Flashcards

bone disorders/osteoporosis (Praveen) Flashcards

1
Q

What is the outer layer of a bone called?

A

cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the inner layer of bone?

A

trabeculae

- spongy, loose meshed lattice of thin strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is bone marrow located?

A

in the spaces between the trabeculae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does bone marrow contain?

A

fat and blood forming tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the end of a bone called?

A

epiphysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is cortical bone made from/found?

A 
Haversian system (blood vessels in centre, osteocytes)
outside of bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2 types of bone

A

cortical

trabesular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is on the ends of long bone?

A

articluar cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What type of tissue is bone?

A

specialised connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

minerals in bone

A

calcium phosphate salts

calcium carbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 cells in bone

A

osteoblasts
osteocytes
osteoclasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

3 types of joints

A

fibrous
cartilaginous
synovial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are osteoblasts?

A

active bone forming cells
produce collagenase bone matrix
secrete enzyme alkaline phosphatase - promotes deposition of Ca phosphate salts in the matrix to calcify the bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do osteoblasts secrete?

A

enzyme alkaline phosphatase

-> promotes deposition of Ca phosphate salts to calcify the bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are osteocytes?

A

inactive mature bone cells

  • as bone matrix is formed/calcified, osteoblasts become incorporated within the bone and are transformed into osteocytes
  • maintains bone tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are osteoclasts?

A

multineucleated cells
bone resorption
remove bone matrix by phagocytosis
dissolve bone salts and release Ca and phosphate ions in circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the osteoclast differentiation factor?

A

RANK-L (ligand)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does RANKL bind to?

A

RANK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is RANK receptor located?

A

on osteoclast precursors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What causes osteoclast precursors to differentiate into mature osteoclasts?

A

RANKL-RANK binding interaction and M-CSF (macrophage colony stimulating factor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is released as mature osteoclasts resorb bone?

A

TGF beta
IGF-1
growth factors
cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What do the released factors from osteoclast resorption stimulate? (TGF beta, IGF1, GF, cytokines)

A

they stimulate osteoblast precursors to develop into mature osteoblasts
these refill the resorption cavaties that osteoclasts left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What causes osteoblast precursors to express RANKL?

A

PTH
shear stress
TGF beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What accelerates bone loss in women?

A

oestrogen deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

hormones that influence bone formation/metabolism

A 
PTH
calcitonin
oestrogen
androgen
GH
glucocorticoids
thyroid hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

local regulators of bone remodelling

A

cytokines - IL6, IL1
prostaglandins
growth factors - IGF1, TGF beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

4 metabolic bone diseases

A

osteoporosis
Pagent’s disease
osteomalacia
Rickets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

presentation of osteoporosis

A

back pain
loss of height
fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

presentation of Pagent’s disease

A

deformity of long bones

pain in hips

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

presentation of osteomalacia

A

generalised bone pain

muscle weakness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

definition of osteoporosis

A

skeletal disorder characterised by the loss of bone mass and deterioration of the bone tissue with an increase in bone fragility and susceptibility to fractures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

causes of osteoporosis

A 
endocrine disorder
malignancy
postmenopausal women
taking LT oral corticosteroids
aging process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

5 causes of osteoporosis in general

A 
genetic
reduced physical activity
reduced nutrition
menopause
aging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does menopause cause osteoporosis?

A

decrease in oestrogen
incresed IL-1, IL-6 and TNF levels
increased expression of RANK, RANKL
increased osteoclast activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How does aging cause osteoporosis?

A

decreaed replicative activity of osteoprogenitor cells
decreased synthetic activity of osteoblasts
decreased biologic activity of matrix-bound growth factors
reduced physical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

basic pathophysiology of OP

A
  • inc in cytokines act OC
  • longer lifespan of OC (dec apoptosis)
  • shorter lifespan of OB (inc apoptosis)
  • shorter lifespan of osteocytes

-> all lead to larger resorptive cavities in bone, bone more fragile, #

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What does deeper/larger resorption cavities in bone lead to?

A

bone is more fragile

bone fractures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

risk factors associated with osteoporosis

A 
personal
- aging female
- small bone structure
- postmenopasual
- FH
lifestyle:
- sedentary
- vit D deficiency
- low Ca intake
- high protein diet
- excessive alcohol/caffiene
- smoking
- drug related
- diet related
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

diseases/conditions that cause reduction in bone mass

A 
Cushing's syndrome
hyperthyroidism
hyperparathyroidism
Coeliac disease (gluten sensitive enteropathy)
IBD
40
Q

drugs that can increase risk of osteoporosis

A 
oral glucocorticoids
pioglitazone (TZDs)
PPIs
cancer treatments (radiation/chemo)
thyroxine
antiepileptic - phenytion/CMZ
gonadal hormone suppression - medroxyprog
immunosuppressive agents
41
Q

When should an assessment for fracture risk be done?

A

all women >65 yrs
all men >75 yrs
-> or under these ages with a risk factor

42
Q

What are risk factors for women <65 and men < 75?

A
  • previous fragility #
  • current/frequent use of steroids
  • Hx of falls
  • FH of hip fracture
  • causes of secondary osteoporosis
  • low BMI (<18.5)
  • smoking
  • alcohol > 14 units/week women, > 21 for men
43
Q

indicators of low bone mineral density

A 
low BMI < 18.5
ankylosing spondylitis (spine inflamed)
Crohn's disease
conditions resulting in prolonged immobility
untreated premature menopause
44
Q

When do you assess fracture risk in under 50 yrs?

A

if they have major risk factors

  • current/frequent use of oral/systemic steroids
  • untreated premature menopause
  • previous fragility fracture
45
Q

What test is used to measure BMD (bone mineral density)?

A

DEXA scan

46
Q

What do DEXA BMD values mean?

A

higher BMD value - more bone mineral present

47
Q

How is BMD measured?

A

Z score - compared to the expected BMD for patient’s age/sex

T score - compared to young adults of the same sex

48
Q

What does DEXA stand for?

A

dual energy x-ray absorptiometry

49
Q

Where does DEXA scan in the body?

A

spine and hip

50
Q

What can DEXA diagnose?

A

osoteopenia - mild/moderate bone loss

osteoporosis - severe bone loss

51
Q

osteopenia T score

A

between -1.0 and -2.5

52
Q

T score for osteoporosis

A

less than -2.5

53
Q

T scores for normal BMD

A

between 2.5 and -1

54
Q

What do T score values above 2.5 on DXA scan indicate?

A

high bone mass
eg. ostroarthritis
(artifically raises bone mineral mass)

55
Q

1st step if patient has clinical risk factors with/without FRAX analysis

A

low risk - reassure

mod/high risk - measure BMD at hip and spine

56
Q

1st step if patient over 55 has fragility fracture

A

measure BMD at spine and hip

57
Q

What to do after BMD measurement?

A

normal (>1) - reassure
osteopenia (-1.5 to -2.5) - lifestyle advice, reassess after 2-5yrs
osteoporosis (< -2.5) - lifestyle advice and drug treatment

58
Q

factors for prevention of osteoporosis

A
  • regular exercise
  • adequate Ca intake
  • oral bisphosphonates (postmenopausal)
  • maintenance of bone mass - weight bearing exercises (walking/jogging/rowing/weight lifting)
59
Q

When is treatment given for osteoporosis?

A

BMD < -2.5
BMD < -1.5 in steroid induced
treatment for patients with vertebral fracture (BMD doesn’t matter)

60
Q

examples of bisphosphonates

A

alendronate
etidronate
risedronate

61
Q

How do bisphosphonates work?

A

inhibitors of bone resorption and increse BMD by altering osteoclast activation and function

incorporate into ATP analogues that accumulate within the osteoclasts and promote their apoptosis

62
Q

What are bisphosphonates similar to?

A

pyrophosphate

63
Q

How do potent amino-bisphosphates work?

A

prevent bone resorption by interfering with the cell surface proteins on the osteoclast membrane by prenylation

preventing osteoclast attachment to bone

64
Q

examples of oral bisphosphonates

A

alendronic acid
ibandronic acid
risedronate sodium

65
Q

When are oral bisphosphonates only recommended?

A
  • patient eligible for risk assessment (w O65, mO75 or under with risk factors)
  • 10yr probability os osteoporotic fragility fracture is at least 1%
66
Q

When are IV bisphosphonates used?

A
  • eligible for risk assessment
  • 10yr probability of osteoporotic fragility at least 10%
  • 10yr probability at least 1% and difficulty taking oral bisphosphonates/ci/not tolerated
67
Q

examples of IV bisphosphonates

A

ibandronic acid

zoledronic acid

68
Q

How to take oral bisphosphonates

A

on empty stomach
with water only
no food/drink/meds for 30 mins after
don’t lie down for 30mins after alendronic acid (irritate oesophagus/GI s/e)

69
Q

s/e with oral bisphosphonates

A

upper GI disturbances (10% pts)

70
Q

dose adjustments with oral bisphosphonates

A

renal impariment
alendronic acid avoided if eGFR <35
- nephrotoxicity risk

71
Q

oral bisphosphonates and hepaic impairment

A

use zoledronic acid with caution in severe hepatic impairment

72
Q

What bisphosphonates to use with glucocorticoid osteoporosis?

A

alendronic acid

risedronate

73
Q

What bisphosphonates to use with hypercalcaemia of malignancy?

A

IV zoledronic acid

pamidromate

74
Q

What bisphosphonates to use with Pagent’s disease?

A

zoledronic acid

oral risedronate

75
Q

What bisphosphonates to use with bone metastases?

A

IV pamidronate

oral ibandronic acid

76
Q

s/e with bisphosphonates

A 
oespohageal irritation
flu-like syndrome
GI disturbances
headache
MSK pain
77
Q

bisphosphonates drug interactions

A

reduced absorption of bisphosphonates with

  • antacids
  • Ca salts
  • Fe supplements
78
Q

What to give if intolerant/ci to oral bisphosphonates?

A

IV zoledronic acid or teriparatide

79
Q

dose of IV zoledronic acid

A

5mg once per year

80
Q

SERM

A

selective ostreogen receptor modulator

81
Q

example of SERM

A

Raloxifene

82
Q

How does raloxifene work?

A

selective agonist or antagonist activities on tissues responsive to oestrogen

83
Q

What does raloxifene stimulate and inhibit?

A

stimulates osteoblasts

inhibits osteoclasts

84
Q

How does raloxifene work as an agonist?

A

agonist on bone and partially on cholesterol metabolism

- dec in total and LDL cholesterol

85
Q

How does raloxifene work as an antagonist?

A

on the hypothalamus or in the uterine or breast tissue

86
Q

What happens when raloxifene undergoes 1st pass metabolism?

A

gives glucuronide in the liver

which undergos enterohepatic recycling

87
Q

What is teriparatide?

A

a recombinant of human parathyroid hormone

88
Q

How does teriparatide work?

A
  • stimulates new formation of bone and increases structural integrity and bone strength
  • increases the no of osteoblasts and activates the osteoblasts already in the bone
  • reduced osteoblast apoptosis
89
Q

dose of teriparatide

A

20mcg OD by SC injection (thigh/abdomen)

for 24mths only

90
Q

teriparatide s/e

A 
nausea
oesophageal reflux
hypotension
dyspnoea
depression
dizziness
91
Q

When is teriparatide given?

A

2nd line for secondary prevention os osteoporotic fragility fractures in pstmenopausal women

  • ci/intolerant to alendronate/risedronate
  • no response to alendronate/risedronate and over 65yrs AND T score of < -4.0 OR < -3.5 with 2+ fractures OR 55-64yrs and T score < -4.0 with 2+ fractures
92
Q

treatment duration of teriparatide

A

max 24 months

course never repeated

93
Q

What is osteomalacia?

A

bone condition in which inadequate mineralisaton of bone results from a Ca or P deficiency or both

94
Q

What is riskets?

A

disorder of vit D deficiency,
inadequate Ca absorption,
impaired mineralisation of bone in children

95
Q

What is Paget disease?

A

progessive skeletal disorder that involves excessive bone destruction and repair
characterised by increasing structural changes of the long bones/spine/pelvis/cranium

96
Q

drugs to treat Paget disease

A

bisphosphonates

calcitonin

PHA223 (43 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions