Bone growth Flashcards
At what stage does the cartilage model develop
Approximately 6 weeks after fertilisation
What is the process of turning cartilage into bone called
Endochondral ossification
Does endochondral ossification start from the outside of the cartilage or from the centre
The centre
What is the first place to turn to bone
Diaphysis - Primary ossification centre
Where are the secondary ossification centres
The epiphyses
What separates the diaphysis and epiphyses during ossification
The epiphyseal/growth plate
What enables bones to grow in length
Epiphyseal/growth plate
At what stage do epiphyses start to fuse with diaphyses
During puberty
What is it called when bones grow in width
Appositional growth
What causes bones to grow in width
Osteoblast activity produces circumferential lamallae
Osteoclasts mould bone shape and form medullary cavity
Features of a joint
- Holds bones together
- involves bone ends
- Involves soft tissue
- Allows control of movement
What are the two key soft tissues
Cartilage and Dense fibrous connective tissue (DFCT)
What are the two key types of cartilage
Hyaline (articular) and Fibrocartilage
What are the three main uses of DFCT
Ligaments
Tendons
Joint capsules
How does cartilage receive nutrients without blood vessels
They are diffused through matrix by joint loading (movement at joint squishes fluid through)
Function of Hyaline cartilage
Resist compression
Why is hyaline cartilage popular in synovial joints
- Moulds to surfaces of bones where they articulate
- Creates smooth surface allowing frictionless movement
Function of fibrocartilage
Resist compression and tension
Why is fibrocartilage used at joints that experience both compression and tension rather than just compression like hyaline
Fibrocartilage contains more collagen fibres than hyaline cartilage making it better at absorbing and distributing force
What does DFCT stand for
Dense fibrous connective tissue
Features of DFCT
Fibroblasts
Collagen fibres
Tightly packed
Slow to heal
Function of DFCT
Resist tension
What do ligaments do
- Connect bone to bone
- Restrict movement (away from themselves)
What do tendons do
- connect muscle to bone
- Facilitates and controls movement
- Contraction of muscles transmitted to bone
Do ligaments or tendons contain more elastin and what does it do
Ligaments contains more
- it resists tension while allowing a little stretch and recoil
What is bony congruence
Sum of bone surfaces that form an articulation (how much the bones touch)
How much soft tissue is required if there is a low bony congruence
More sot tissue is required to provide support
What are the three different joint classifications in order of movement allowed
Fibrous - least movement
Cartilaginous - some movement
Synovial - most movement
What is a tissue
Cells grouped together in a highly organised manner according to specific structure and function e.g. DFCT
What is a structure
Something formed of a tissue e.g. ligament
What is the tissue found on fibrous joints and what is the function
Tissue - DFCT
Function - limit movement, provide stability
What is the tissue found on cartilaginous joints and what is the function
Tissue - fibrocartilage
Function - some movement
What is the tissue found on synovial joints and what is the function
Tissue - many
Function - allow lots of movement
