Brainscape's Knowledge GenomeTM

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


See full index

ODDR- e lecs > Mechanisms of bone loss > Flashcards

Mechanisms of bone loss Flashcards

1
Q

Why is the area of the gingival cuff important?

A

It is critical in maintaining the correct relationship between the gingival and the tooth thereby protecting the deeper tissues of the PDL and alveolar bone

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

Name the main cells found in the gingival cuff

A
  1. Osteoclasts
  2. Osteoblasts
  3. Fibroblasts
  4. Macrophages
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What do osteoclasts do?

A

They are bone resorbing cells

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

What are the characteristics of osteoclasts?

A

They are very large and multinucleate

They have a brush border when adjacent to the bone surface where active resorption is occurring

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

Where are osteoclasts situated?

A

They are situated in resorption pits called Howship’s lacunae

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

What do osteoblasts do?

A

They are bone forming cells

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

What are the characteristics of osteoblasts?

A

They are characteristically found as a single cell layer lining the bone surface
They are active protein producing cells

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

What do fibroblasts do?

A

They are responsible for forming and painting the collagenous matrix of the ligament and marina prop

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

Describe the fibroblasts

A

They are very active cells

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

Why are fibroblasts active cells?

A

As they have a rapid turnover time for their matrix in the PDL tissues

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

What is the origin of the macrophages?

A

They are of monocyte lineage

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

Name the process by which collagen is degraded

A

Phagocytosis

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

What does the secretion and degradation of collagen have to be in synchrony?

A

So that the overall level of matrix is constant

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

How are osteoclasts formed?

A

Under the control of a growth factor called RANKL, monocytes fuse and form osteoclasts

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

Where does the growth factor RANKL originate from?

A

Adjacent osteoblasts

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

Describe where RANKL is found in a cell

A

RANKL may be free within the matrix or bound to the osteoblast cell membrane

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

What does RANKL bind to?

A

It binds to a specific receptor on the monocytes

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

How does the osteoblast control the rate of osteoclast formation?

A

By modulating the production of RANKL

19
Q

What happens once the osteoclasts fully differentiated?

A

It starts to degrade bone

20
Q

How do osteoclasts degrade bone?

A

They pump protons into the adjacent bone to dissolve minerals and then potent enzymes, mainly Cathepsin K, to breakdown the bone matrix.

21
Q

Which enzyme is mainly released to break down bone?

A

Cathepsin K

22
Q

Which growth factor helps regulate the formation of osteoclast?

A

RANKL

23
Q

What is the modulation of RANKL production influenced by?

A

Influenced by the applied loading on the bone (either directly by the osteocytes and osteoblasts detecting the mechanical stresses within the bone itself)
OR
Indirectly via macrophages

24
Q

What do macrophages reason to that can help modulate the production of RANKL?

A

They respond to loading by the production of cytokines such as interleukin-1 (IL-1).

25
Q

The action of what increase the production of RANKL by osteoblasts?

A

By the action of IL-1

26
Q

What is maintenance of the alveolar bone dependent on?

A

On sufficient load derived fro the presence of functioning teeth

27
Q

What happens to the alveolar bone if teeth are lost?

A

The alveolar bone will be resorbed as the balance is upset and bone degradation outstrips formation.

28
Q

What situation can tip the balance between formation and destruction more towards reposition?

A

can also be tipped in the direction of bone resorption by the intervention of certain exogenous plaque bacterial- derived material e.g lipo-polysaccharide (LPS) and bacterial enzymes which directly or indirectly affect the cells and matrix in the gingival cuff region.

29
Q

What situation can tip the balance between formation and destruction more towards destruction??

A

Losing teeth or having them extracted

30
Q

What is the colloquial name for the periodontal disease a lot of sheep suffer from?

A

Broken mouth

31
Q

What happens if we add a bacterial plaque adjacent to the epithelium in the PDL?

A

LPS derived from this plaque will pass through the epithelium and interact with the cell populations in the connective tissue and on the bone surface.

32
Q

On what cell does LPS have the greatest effect?

A

Macrophages

33
Q

What effect can LPS have on osteoblasts?

A

to up regulate RANKL production

34
Q

What effect can LPS have on monocytes?

A

To accelerate their fusion to osteoclasts

35
Q

What effect can LPS have in macrophages?

A

stimulates an increase IL-1 production

36
Q

Name some targets for IL-1

A
  1. Osteoblasts

2. Fibroblasts

37
Q

How does an increase in IL-1 affect the osteoblasts?

A

RANKL production is upregulated which in turn leads to further recruitment of monocytes and the formation of more osteoclasts

38
Q

How does an increase in IL-1 affect the Fibroblasts?

A

Triggered to produce their own IL-1,some of which again acts upon the osteoblast population and some acts in a paracrine fashion to stimulate yet more IL-1 from neighbouring cells.

The IL-1 also stimulates the fibroblasts to produce extracellular collagenases

Also stimulates the fibroblasts to produce another cytokine, interleukin 6 (IL-6).

39
Q

What does interleukin 6 (IL-6). do?

A

This cytokine increases the effectiveness of RANKL in stimulating osteoclast formation.

40
Q

How does an increase in IL-1 affect the osteoclasts?

A

Can upregulate cathepsin K production and thereby increase the effectiveness of individual cells in degrading the bone matrix

41
Q

Summarise the actions of LPS produced from bacteria

A
  1. Acts on osteoblasts to up regulate RANKL production
  2. Acts on monocytes o increase osteoclast formation
    3, Acts on macrophages to up regulate IL-1 production
42
Q

Summarise the actions of IL-1 produced from bacteria

A
  1. Acts on osteoblasts to up regulate RANKL production
    2, Act on fibroblasts to up regulate IL-1 production
  2. Acts on fibroblasts to to up regulate IL-6 production
  3. Act on fibroblasts to induce collagenase production
43
Q

What effect does the presence of bacteria have on alveolar bone?

A

Leads to alveolar bone loss

44
Q

How does the presence of bacteria lead to alveolar bone loss?

A
  1. Direct stimulation of osteoclast formation
  2. The production of an inflammatory response including the production of numerous cytokines which directly or indirectly increased osteoclast formation and activity
  3. A loss of loading on the bone which can itself result in further bone loss

ODDR- e lecs (5 decks)

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