Brainscape's Knowledge GenomeTM

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


See full index

LIFESCI 3AA3 > TOPIC FIVE: BONE HEALTH > Flashcards

TOPIC FIVE: BONE HEALTH Flashcards

1
Q

Are hip fractures expensive

A

Yes! Cost $27 000 to treat

Big impact on healthcare services

Link between fractures, risk of death and healthcare services

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

Prevalence of osteoporosis in men and women

A

1/3 women
1/5 men

there is a role of estrogen

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

Is there an effect on QoL with osteoporosis?

A

Yes

After someone has experience a fracture, there is a decrease in physical function, there is a greater change in pain, there is a change in general health, vitality, social function, mental health

Seems to affect people for a number of different reasons

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

What is osteoporosis

A

Low bone mineral density and microarchitecture deterioration resulting in risk of fracture

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

What is more commonly used to diagnose osteoporosis - BMD or microarchitecture

A

BMD

The microarchitecture deterioration is harder to use to diagnose and is often less considered in osteoporosis

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

What is the structure of the inside of bone

A

There is a cortical shell and a bone that looks like honeycomb made up of trabeculae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is trabeculae important for

A

Bone strength

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

What is there an imbalance of in osteoporosis

A

Bone resorption and bone formation

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

What is used along with BMD to diagnose these days

A

Used to just use BMD to diagnose osteoporosis but now also use risk factors to predict the risk of fracture

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

How many SD decrease in BMD is indicative of increased fracture risk

A

1 SD decrease in BMD in any site increases the risk of fracture

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

What are the most common site to test BMD

A

Wrist
Hip
Vertebrae

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

What are the main osteoporotic fractures

A

Vertebral fracture
Hip fracture
Wrist fracture
Proximal humerus fracture

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

What is the wrist fracture usually referred to as

A

The lucky break

Individuals with wrist fracture may go on to be assess for osteoporosis and are often treated which may prevent them from having a more detrimental fracture

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

What is DXA

A

Dual x-ray absorptiometry

Used to measure BMD

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

What is best at predicting fracture risk

Just clinical factors
Just BMD
Clinical factors + BMD

A

Clinical factors + BMD

Has the highest sensitivity to specificity

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

What is a T score

A

When someone gets a BMD test done, there results are presented as a T score

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

What does a positive T score mean

A

suggesting that the bone health is better than premenopausal bone density

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

What does a negative T score mean

A

suggesting that the bone health is worse than premenopausal bone density

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

What does a lower T score mean

A

A lower (more negative T score) puts the risk of fractures even higher

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

When do we achieve peak bone health

A

20s

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

What happens 5-7 years around menopause (%)

A

There is a steep loss of bone density (12%)

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

Other risk factors for decrease bone health

A

lack of exercise, poor nutrition, loss of testosterone

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

What is the T score used to diagnose osteoporosis

A

-2.5

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

What is the T score used to diagnose osteopenia

A

-2.5 to -1

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

What is the issue with just using T scores to diagnose

A

People within the osteopenia and the normal range also fracture their bones so we can see using BMD only is not the best

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the relationship between medication and fracture risk

A

There is a really big reduction in fracture risk with only a small amount in change in BMD

Maybe the medication are helping something else

27
Q

What are limitations to BMD

A

It is 2D (missing volumetric assessment)

Does not tell us about cortical and trabecular bone architecture

There can be artifacts that the bone scan picks up (could be osteophytes)

28
Q

What are osteophytes

A

Abnormal bone growth that develops due to bone on bone contact

Common in osteoarthritis and type 2 diabetes

29
Q

What are the main components of bone and the %

A

40% proteins (T1 collagen)
60% mineral (hydroxyapatite which Ca is apart of)

There is a balance between having enough protein and mineral in bone to allow to ben when you apply load

Proteins allow bend
Minerals allow hardness

30
Q

What are structural bone qualities

A

Bone size, shape
Cortical thickness and porosity
Trabecular boen microarchitecture

31
Q

What are mineral bone qualities

A 
Crystallinity 
Osteon count 
Collagen cross-links 
Microdamage 
Mineralization
32
Q

What is the rate of bone turnover

A

10% of your skeleton is completely turned over each year

Every 10 years, you will have a new skeleton

The process of resorption and formation takes 3-6 months

33
Q

What are osteoblast

A

Build bone

34
Q

What are osteoclasts

A

Break bone

35
Q

Communication between osteoblasts and osteoclasts

A

When the osteoclasts go into absorb the bone, they communicate to the osteoblast to go in and add more osteoids to the bones

The osteoid becomes mineralized and becomes bone

36
Q

What are the four stages of bone remodelling

A

Resportion - reversal - formation - resting

37
Q

Why does bone remodelling take place

A

To release Ca stored in bone if there is not enough in the diet

99% of Ca in our body is stored in bones and Ca is extremely important for many processes

38
Q

What are mirocracks

A

Every time we but load on our bones, we are stimulating this process to take place - We create microcracks when we apply load which is a health process which stimulates resportion and formation of new bone

39
Q

What cells do osteoclast originate from

A

Hematopoietic stem cells

40
Q

What cells do osteoblast originate from

A

Mesenchymal stem cells

41
Q

What do osteoclast secrete

A

Osteoclasts secrete HCl, Cathepsin K and MMP to break down the bones

42
Q

What do osteoblasts secrete

A

Osteoblasts secrete osteocalcin, alkaline phosphatase osteoid, hydroxyapatite to build the bone

43
Q

What are the pathways that trigger osteoblast activity

A

Runx2 is a transcription factor that stimulates osteoblast formation

The Wnt formation also increases osteoblast proliferation from MSC

Scleostin turns off osteoblast formation by downregulation of the Wnt pathways to prevent excessive bone formation

44
Q

What are pathways that trigger osteoclasts

A

RANKL (receptor activator of nuclear factor kB ligand) turns on the activation of osteoclasts

CSF (Colony stimulating factor) turns on the production of osteoclasts from the stem cells

45
Q

What is Cleidocranial dysplasia

A

Mutation on Runx2 gene

Hypoplasia of clavicles and bones in face

Sunk in clavicles

Not as much bone formation

46
Q

What is Van Buchem disease

A

Mutation on SOST gene - This gene is the sclerostin encoding gene

Hyperostosis of mandible, skull, ribs, long bones

Excessive bone formation

47
Q

Is there increased of decrease bone resorption after menopause

A

Increased

When women lose estrogen, there is increase in bone resorption

48
Q

What happens when women are prescribed estrogen or progesterone

What is the mechanism

A

Women prescribed estrogen and progesterone have decrease fracture risk

Estrogen decreases the production of RANKL and CSF

49
Q

What do corticosteroids do to bone (mice and humans)

A

In the mice, there is more osteoblasts in the control group vs. the treatment with prednisolone
• 86% reduction

In the humans, there is decrease in BMD of the lumbar in the corticosteroid group

50
Q

What is the mechanism behind corticosteroids and bone

A

Glucocorticoids inhibit the WNT pathway and therefore limit the production of osteoblasts that mature

51
Q

What happens when we load out bones/do exercise

A

Every time we move our bodies, we have microcracks which promote bone growth

When we move, we have fluid that flows through the canaliculi in the bones. The fluid stimulates osteoblasts to build bone

Increasing pressure applied to the bone increase the amount of bone formed

52
Q

What is the mechanism behind exercise and bone health

A

Fluid flows through the bone which stimulates osteoblasts

When you flex muscles there is a release of growth hormone which stimulates osteoblasts

53
Q

What is Wolffs law

A

When you load bone, it will get stronger

54
Q

Is estrogen protective for bone health? How?

A

Yes

Limits bone resorption

55
Q

Estrogen wrt osteoclast

A

Estrogen inhibits RANKL and CSF

56
Q

What does Ca and vitamin D do in terms of osteoblasts

A

Stimulate formation of osteoblasts

57
Q

What does glucocorticoids do wrt osteoblast

A

Inhibit the Wnt pathway

58
Q

Do individuals with diabetes have higher or lower T scores

A

Higher!

Individuals with diabetes seem to have better bone density (higher bone density)

59
Q

Mechanism wrt diabetes and bone density

A

Obesity and type 2 diabetes often go together

Obesity can cause increase leptin (hormone secrete from adipocytes) which stimulates osteoblast and decreased RANKL

Hyperinsulinemia may develop from insulin medication, or high levels of blood glucose - insulin stimulates IGF (insulin like growth factor) which stimulates osteoblast cells

60
Q

Do individuals with diabetes have a higher or lower fracture risk

A

Higher

61
Q

Mechanism wrt to diabetes and higher fracture risk

A

Insulin is a marker for diabetes duration

someone who has had diabetes for longer maybe they are more prone to falls due to the muscle impairments and neuropathy

maybe the diabetes might affect bone quality?

62
Q

What component of bone is greater in individuals with diabetes

A

Individuals with diabetes had more mineralized bones compared to those without diabetes

The holes in the trabeculae were actually larger

The increase in bone mineralization might be due to a suppression of bone turnover - more mineralized might make it more brittle

63
Q

Does medication for osteoporosis work for patients with diabetes

A

No

The risk of fracture is higher than those without diabetes

LIFESCI 3AA3 (6 decks)

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