Lecture 7: Bone Tissue - Growth and Pathology Flashcards
What is ossification?
The process of transforming cartilage to bone.
What do bones begin as?
A cartilage model.
What is the primary center of ossification?
The diaphysis or shaft.
What is the secondary center of ossification?
The epiphysis.
What is another name for the growth plate?
Epiphyseal plates.
What is the growth plate made of?
Cartilage.
How does a bone grow in length?
With a growth plate.
How does a bone grow in width?
Osteoblasts in the periosteum increase bone width.
How does bone moulding take place?
Osteoclasts from the Endosteum mould the bone shape and form the medullary cavity.
What is the endeosteum?
Thin vascular membrane of connective tissue that lines the inner surface of the bony tissue that forms the medullary cavity of long bones.
What is the medullary cavity?
The cavity in the diaphysis of a long bone, where marrow is stored.
What is bone pathology a result of?
An imbalance of osteocyte and osteoblast activity.
What causes osteoporosis?
When the osteoclasts ‘overtake’ or are more productive than osteoblasts.
What does osteoporosis do to the cancellous bone?
Loss of volume.
What happens to compact bone in osteoporosis?
It becomes thinner and more porous.
What may happen to the vertebrae as a result of osteoporosis?
Compression fractures of the vertebrae.
What are 4 causes of osteoporosis?
- Loss of oestrogen due to aging
- Lack of exercise
- Nutritional factors
- Peak bone mass past (bone as a bank)
What happens in the first stage of bone fracture healing?
Formation of a haematoma at fracture ends, phagocytes clean up broken bone pieces.
What happens in the second stage of bone fracture healing?
Formation of fibrocartilaginos callus. Fibroblasts appear and create a weak structure, then some for chondroblasts, and the chondroblasts form a fibrocartilaginos callus.
What happens in the third stage of bone fracture healing?
The fibrocartilaginous callus forms a bony callus by ossification with osteoblasts.
What happens in the fourth stage of bone fracture healing?
Remodelling.
What is Pseudoarthrosis?
A ‘false joint’ created after a fracture hasn’t healed properly.
What are the three main types of fractures?
- Closed, simple fractures
- Open, compound fractures
- Greenstick fractures.
