Brainscape's Knowledge GenomeTM

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


See full index

Oral biology > OB P7- Bone and calcium > Flashcards

OB P7- Bone and calcium Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what are the functions of bone?

A 
>  Skeletal :
– Protects organs
– Provides rigidity
– Allows attachment of muscles and teeth 
– Movements
>  Container for marrow   
> Ca2+ pool
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why understand bone?

A
  • Regional differences in the mouth (Local anaesthesia)
  • Bone changes in the mouth (e.g. to extraction of teeth)
  • Orthodontic tooth movements - Osseointegration – implants
  • Bisphosphonates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the bone composition?

A 
60% mineral :
- Largely hydroxyapatite
25% organic :
-90% Type I collagen
- 10% grounds substance
  15% water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does collagen do to bone?

A

collagen is a fibrous structural protein which gives elasticity to bone

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

what are the 2 types of bone in the jaw?

A
  • Alveolar bone - contains the tooth

- Basal bone - basic structure of the jaw

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

why is fitting a lower denture difficult?

A

there is no ridge to fit the lower denture over as the bone resorbs away once teeth are removed

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

what makes a lower denture fit better/

A

2 implants inserted that the denture clips into

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

what are the two different types of bone around the tooth?

A
  • Cortical bone (compact bone - dense)

- Trabecular bone ( spongy , cancellous bone)

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

why does the density and porosity affect local anaesthesia?

A

cortical bone is thin around the upper teeth and porous so anaesthetic will diffuse through

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

what layer of bone surrounds the tooth?

A

lamina dura (bundle bone - cribriform plate)

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

why is it called lamina dura?

A

Due to radiographic appearmace - white ridge around teeth

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

what is the intraligamentary anaesthesia technique?

A

stick needle down PDL space between bone and tooth
inject small amount of anaesthetic -allows us to apply high pressure
(passes out of the holes and diffuses through trabecular bone and reaches apex

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

what are the 3 types of lamellae?

A 
Circumferential
-Outside of most cortical bone   
Concentric
-Organised in Haversian systems / osteons   
Interstitial
- Remnants of old lamellae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is found in the middle of the lamellae?

A

blood vessels

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

what lines are found in the lamellae?

A

cementing lines

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

what is important about osteocytes in lamellae that is different to cementocytes?

A

osteocytes have processes that go in both directions whereas cementocytes only have one process that points outwards

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

what are the two types of bone formation?

A
  • endochondral

- intramembranous

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

Describe endochondral ossification.

A

Cartilage -> calcified cartilage -> bone

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

Describe intramembranous ossification.

A
  • Condensation of mesenchymal cells
  • Osteoblasts – produce osteoid matrix
  • Woven bone
  • Primary osteon formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is woven bone?

A

when collagen is randomly organised

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

Describe the formation of primary osteons.

A
  • connective tissue condensation around Blood vessels + advancing layer of osteoblasts laying down woven bone
  • as osteocytes advance, some surround the edge of the condensation and some advance still laying down woven bone
  • forms lamellae around the dental vessel
  • primary osteons surrounded by woven bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe osteoblasts.

A

– Mesenchymal or ectomesenchymal derived
– On bone surface (periostuem , endosteum )
– Produce osteoid matrix

23
Q

Describe osteocytes.

A 
– Trapped osteoblasts
– (cf cementocytes)
– Cell processes
– Linked by gap junctions 
– Cells vital
24
Q

what are osteoclasts.

A

– Derived from haemopoietic source
• Macrophage/monocyte line
– Large multinucleate cells

25
Q

where are osteoclasts found and what is their role?

A

– In Howships Lacunae:
• Dissolve bone mineral – acid
• Breakdown organic matrix - enzymes

26
Q

How often is bone remodelled?

A

continuous

27
Q

what occurs during the turnover of bone?

A

resorption and deposition

28
Q

how often is bone completely replaced?

A

every 10 years:

– Keeps skeleton effectively engineered for its use – Helps maintain plasma Ca2+ levels

29
Q

How is bone remodelled?

A

– Cutting cone - osteoclasts

– Filling cone – osteoblasts

30
Q

what does bone turnover result in?

A

secondary osteons

31
Q

How much calcium is in the Body?

A

> 1Kg Ca2+ in body
99% in bones and teeth
– Only 0.4% exchangeable
1% in body fluids

32
Q

Can calcium be taken out of bone and teeth?

A

calcium can be taken out of bone in small amounts but NOT teeth

33
Q

what can remove calcium from bone?

A

osteocytes and osteoclasts

34
Q

what are the roles of Ca2+?

A 
-Membrane permeability:
> Decreases membrane permeability (esp PNa)
> Decreases cell excitability
> Low Ca2+ -> spontaneous APs - results in tetany
- Excitation – contraction coupling   
- Excitation – secretion coupling
-  Hard tissue formation
-  Blood clotting
-  Enzyme reactions
-  Secretions – e.g. milk
35
Q

what is quick Ca2+ regulation?

A

Rapid exchanges between bone and ECF

36
Q

What is slow Ca2+ regulation?

A

– Intestinal absorption

– Renal excretion

37
Q

what does the parathyroid hormone do?

A
  • Essential for life
  • Release in response to falling [Ca2+]plasma
  • increases [Ca2+]plasma
  • Prevents hypocalaemia
  • Withdraws [Ca2+] from the bone bank
38
Q

Describe the fast Ca2+ efflux to plasma.

A

– Small labile pool of Ca2+ in bone

– Involves osteocytes - osteocytic osteolysis

39
Q

Describe the slow Ca2+ efflux to plasma.

A

– Bone dissolution
– Shift remodelling to favour resorption
– Involves osteoclasts

40
Q

what effect does the parathyroid hormone have on the kidney?

A

Reduced excretion of Ca2+

41
Q

what is caused by deficiency in the parathyroid hormone?

A
  • Iatrogenic parathyroid gland damage
  • Tetany
  • Asphyxiation
42
Q

what is caused by excess of the parathyroid hormone?

A
  • Hyperplasia of PT gland
  • Tumours
  • Weak bones
  • Ectopic mineralisation
43
Q

what are “C” cells on thyroid gland?

A

calcitonin

44
Q

what is the role of calcitonin?

A

Prevents [Ca2+] plasma becoming high

45
Q

what is the action of calcitonin?

A
  • Reduce osteocyte activity
  • Reduce osteoclast activity
  • Reduce osteoclast numbers
46
Q

what is essential for Ca2+ absorption In the intestine?

A

Vitamin D - Cholecalciferol

47
Q

when is Vitamin D - Cholecalciferol produced?

A

Produced in skin in response to sunlight on a precursor

48
Q

what is the action of vitamin D?

A

Increase Ca2+ absorption in the intestine

49
Q

what does BRONJI stand for?

A

Bisphosphonate Related Osteonecrosis of the Jaws

50
Q

what does MRONJ stand for?

A

Medication related osteonecrosis of the jaws (used now)

51
Q

what are biphosphates used for?

A

– Osteoporosis – reduce fracture rates

– Bone metastases

52
Q

how do biphosphates work?

A

Reduce osteoclast activity – reduce bone breakdown

53
Q

How is MRONJ caused?

A

– Impaired bone turnover -> exposed bone after extraction

Oral biology (29 decks)

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