1. Bone and Cartilage Flashcards Preview

BDS2 BAMS Oral Biology > 1. Bone and Cartilage > Flashcards

Flashcards in 1. Bone and Cartilage Deck (40)
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1
Q

Macroscopic types of bone (2)

A

Cortical (compact) - 85% of skeleton

Cancellous (spongy) - §5% of skeleton

2
Q

Composition of alveolar bone (2)

A

Cortisol bone

With nutrients canals containing BVs

3
Q

What makes up ECM of bone

A

Ground substance

4
Q

Definition of ground substance

A

Semi-fluid gel

5
Q

Composition of ground substance (2)

A

Polysaccharides

Glycos-amino-glycans (GAGs) - hyaluronic acid, proteoglycans (chondroitin SO4)

6
Q

Microscopic types of bone (2)

A

Woven bone

Lamellar bone

7
Q

Features of woven bone (4)

A

Rapidly laid down
Irregular collagen deposition
Present in foetus/fracture repair
Contains many osteocytes

8
Q

Features of lamellar bone (4)

A

Laid down more slowly
Collagen fibres laid down in parallel
Normal form in adults
Contain fewer osteocytes

9
Q

Composition of compact bone (5)

A
Laid down in concentric lamellae
Forms longitudinal columns
Organised in Haversian systems around central canal
Contains lateral canals
Canals contain BVs
10
Q

Composition of cancellous bone (5)

A

Network of thin trabecular consisting of lamellae
Osteocytes present
No obvious Haversian system
Bone is thin, nutrients can diffuse in
Bone marrow present in space between trabeculae

11
Q

Where are osteoblasts found and what are they derived from

A

Surface of bone

Mesenchymal stem cells

12
Q

Function of osteoblasts

A

Synthesise and secrete collagen fibres which form a matrix

13
Q

How is this matrix mineralised

A

By calcium salts

14
Q

Definition of osteocyte

A

Osteoblasts that become trapped within mineralised bone

15
Q

Where are osteocytes found

A

Lie within spaces called lacunae

16
Q

How do osteocytes communicate

A

Via cytoplasmic processes that lie in canaliculi

17
Q

Definition of osteoclasts and where do they derive from

A

Large, multinucleate cells

Derived from haemopoietic stem cells

18
Q

Function of osteoblasts

A

Resorb bone

19
Q

Where are osteoclasts found

A

Concavities in bone (Howship’s lacunae)

20
Q

What do osteoclasts control

A

Bone remodelling (turnover)

21
Q

What is bone remodelling

A

Removal and replacement of bone without a change in overall shape

22
Q

How is bone remodelling regulated (2)

A

Hormones (PTH, calcitonin)

Paracrines (various cytokines)

23
Q

What is the reversal line

A

Histological feature

Scalloped edge shows where bone resorption changes to bone deposition

24
Q

What does tooth movement require

A

Remodelling of adjacent soft and hard tissues

25
Q

When do these movements occur (3)

A

During eruption
During mesial drift (post-eruption)
Orthodontic forces

26
Q

Definition of cartilage

A

Semi-rigid, unmineralised CT that contains a matrix similar to bone

27
Q

Types of cartilage (3)

A

Hyaline cartilage
Fibrocartilage
Elastic cartilage

28
Q

Location of hyaline cartilage (6)

A
Widespread
Larynx
Nasal septum
Trachea
Costal cartilage
Articular surfaces
Embryonic skeleton (precursor to bone)
29
Q

Location of fibrocartilage (2)

A

Intervertebral discs

Pubic symphysis

30
Q

Location of elastic cartilage (3)

A

External ear
Epiglottis
Eustacian tube

31
Q

What what cells are cartilage formed

A

Chondroblasts

32
Q

What are chondrocytes and what do they contain

A

Chondroblasts trapped in the matrix

Stores of lipid and glycogen

33
Q

Are cartilage cells vascular or avacular

A

Avascular

34
Q

Types of bone growth (2)

A

Endocondral ossification

Intramembranous ossification

35
Q

Features of endochondral ossification (4)

A

Long bones
Cartilage precursor
Cartilage proliferation
Cartilage replaced with bone

36
Q

Features of intramembranous ossification (3)

A

Flat bones
Bone formed de novo in CT
No cartilage precursor

37
Q

How does cranial base growth occur

A

Endochondral ossification

38
Q

How does sphenoid bone growth occur

A

Endochondral and intramembranous ossification

39
Q

Definition of achondroplasia

A

Genetic defect of cartilage growth

Endochondral bone growth is impaired, intramembranous bone growth is unaffected

40
Q

How does the condyle grow

A

Endochondral ossification