Bone growth: Tissues of joints Flashcards
(46 cards)
When we were a fetus, we did not have bones. Instead,
we had a skeleton made out of cartilage.
When does the cartilage model start
6 weeks after fertilisation
Endochondral ossification
The process of turning cartilage into bone
Primary ossification centre
The diaphysis (shaft) is the primary ossification centre, which means it is the first place that turns into bone. The epiphyses remain as cartilage.
Secondary ossification centres
After the shaft of the bone is slowly developing and gaining structure, the epiphyses will be the secondary ossification centre.
The epiphyses is separated from the diaphysis by
the epiphyseal/growth plate.
Explain the process of secondary ossification in the epiphyses
Blood vessels and osteoblasts will make way in the centre of the cartilage and start turning into bone tissue. It will do that until all of the space is filled up with bone tissue. It won’t turn all of the cartilage into bone yet.
Bone growth in length is enabled by
epiphyseal plates or growth plates.
Appositional growth is bone growth in
width
Explain the process of appositional bone growth
Osteoblast activity on the outside of the bone will produce circumferential lamellae, wrapping around the bone increasing it outwards to make it wider and wider. On the inside of the medullar cavity, osteoclasts break down the bone from the inside to hollow it out more to create a balance of growth without the bone being too heavy.
To create a balance of bone growth without making it too heavy,
osteoclasts mould bone shape and form medullary cavity
Functions of joints
-Hold bones together
-Involves bone ends
-Involves soft tissues to attach
-Allows control of movement
DFCT
Dense fiber connective tissue
Key soft tissues
Cartilage and dense fiber connective tissue
Three types of cartilage
Hyaline, elastric and fibrocartilage
Dense fibre connective tissue
- Ligaments
-Tendons
-Joint Capsules
Ground substance is made out of
sticky sugar components
Chondro meaning
Related to cartilage
Chondrocytes …
sit in the lacuna just like the osteocytes do in bone. They make the extracellular matrix of the cartilage. They release components in to the environment of the cell.
What kind of fibres are collagen fibres
Dense protein fibres
How are nutrients diffused through the matrix
Through a process called joint loading which is where at the end of the bones there is cartilage and next to it is fluid that has nutrients to it. Each time we move, it squishes the fluid into the cartilage and gives it the nutrients that it needs
Cartilage is a-….
avascular which means that there are no blood vessels present
Meaning of hyaline
Clear or transparent or see through
Function of the hyaline articular cartilage
Resist compression so when you push on it, it won’t crumble.
