Brainscape's Knowledge GenomeTM

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


See full index

PHA332 > Wk 15: Bone disorders + osteoporosis > Flashcards

Wk 15: Bone disorders + osteoporosis Flashcards

1
Q

What are osteoblasts?

A
  • bone forming: produce collagenase bone matrix

- Secrete alkaline phosphatase: promotes deposition of calcium phosphate salts to calcify bone

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

What are osteocytes?

A

Inactive mature bones after bone matrix formed

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

What are osteoclasts?

A
  • Multinucleated cells concerned w/ bone resorption

- Remove bone matrix by phagocytosis, dissolve bone salts + release calcium + phosphate ions in circulation

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

Outline the mechanism of action of bone remodelling

A
  • PTH, shear stress, TGF-B cause osteoblast precursor to express RANKL
  • RANKL bind to RANK on osteoclast precursor
  • Binding interaction w/ macrophage colony stimulating factor cause osteoclast precursor to diff. into mature osteoclast
  • Mature osteoclast resorb bone, matrix bound factors (TGF-B, IGF-1), growth factors + cytokines released
  • Stimulates osteoblast precursor to develop into mature osteoblast - refills resorption cavities excavated by osteoclast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the typical 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
6
Q

What is the typical presentation of paget’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
7
Q

What is the typical presentation of osteomalacia?

A
  • Generalised bone pain
  • Muscle weakness
  • Uncommon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the causes of osteoporosis?

A
  • Result of endocrine disorder/malignancy
  • Aging
  • Postmeno women
  • Men >50
  • LT oral corticosteroids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does menopause cause osteoporosis?

A
  • Dec serum oestrogen
  • Inc IL-1 + 6 + TNF
  • Inc expression of RANK + RANKL
  • Inc osteoclast activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does aging cause osteoporosis?

A
  • Dec replicative activity of osteoprogenitor cells
  • Dec synthetic activity of osteoblast
  • Dec activity of matrix-bound growth factors
  • Red physical activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Outline the pathophysiologic of osteoporosis

A
  • Inc cytokines = activation of osteoclast
  • Deeper, larger resorption cavities in bone bc osteoclast longer lifespan
  • Fragile bones bc mechanosensing is decreased tf microdamage in bone
  • Bone fracture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the drugs that inc risk of osteoporosis?

A
  • Oral glucocorticoids
  • Pioglitazone
  • PPI
  • Thyroxine
  • Phenytoin, CMZ
  • Immunosuppressive agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are indicators of low bone mineral density?

A
  • Low BMI
  • Crohn
  • Prolonged immobility
  • Untreated premature meno
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the T score for osteopenia?

A

-1 + 12.5

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

What is the T score for osteoporosis?

A

< -2.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the lifestyle advice for preventing osteoporosis?

A
  • Exercise: walking, jogging, rowing + weight lifting
  • Calcium intake
  • Oral bisphosphonates for prevention of postmeno osteo
17
Q

What do bisphosphonates do?

A

Inhibit bone resorption + inc BMD by altering osteoclast activation + function

18
Q

Give examples of oral bisphosphonates

A
  • Alendronic acid
  • Ibandronic acid
  • Risedronate sodium
19
Q

When are oral bisphosphonates recommended?

A
  • Eligible for risk assessment

- 10 year probability of osteoporotic fragility fracture = 1%

20
Q

Give examples of IV bisphosphonates

A
  • Ibandronic acid

- Zoledronic acid

21
Q

When are IV bisphosphonates recommended?

A
  • Eligible for risk assessment
  • 10 year probability of osteoporotic fragility fracture = 10%
  • 10 year probability = 1% + difficulty taking oral bisphosphonates
22
Q

What are the patient counselling on bisphosphonates?

A
  • Oral on empty stomach + water only, no food for 30 minutes
  • Don’t lie for at least 30 mins after alendronic acid
  • Oral = GI disturbances
  • Alendronic acid avoided if eGFR <35
  • Zoledronic acid caution in severe hepatic impairment
23
Q

What are the side effects of bisphosphonates?

A
  • Oesophageal irritation
  • Flu like
  • GI disturbance
  • Headache
  • MSK pain
24
Q

What is first line treatment of bisphosphonates?

A
  • Oral

- IV zoledronic (5mg per year)/ teriparatide if intolerant

25
Q

Selective oestrogen receptor modulator (SERM)

A
  • Raloxifene
  • Selective agonist or antagonist activities on tissues responsive to oestrogen
  • Stim osteoblast + inhibit clast
  • Agonist on bone + partially on cholesterol metabolism
  • Antagonist hypothalamus, uterine + breast tissue
  • 1st pass metabolism
26
Q

Teriparatide

A
  • Recombinant fragment of parathyroid hormone
  • Stimulates new bone formation + inc structural integrity + bone strength
  • Inc blast by activating blast in bone
  • Red blast apoptosis
27
Q

How is teriparatide given?

A

20 mcg OD SC injection for 24 months

28
Q

What are the side effects of teriparatide?

A
  • Nausea
  • Oesophageal reflux
  • Hypotension
29
Q

Give examples of disorders involved in softening the bones

A
  • Osteomalacia - calcium/phosphate deficient

- Rickets - Vit D deficient

30
Q

What are drugs used for paget disease?

A
  • Bisphosphonates

- Calcitonin

PHA332 (34 decks)

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