Bone Disorders Flashcards
What is bone?
Ridged inflexible mineralised connective tissue
What is bone mineralised by?
Calcium and phosphate salts
Why are bones important?
- Provides physical integrity/ support
- Protects squishy organs
- Allows for insertion of muscles and tendons
- Provides minerals
- Important in haematopoiesis
What minerals does bone provide
- Calcium
- Phosphorous
- Magnesium
What is haematopoiesis?
It is the formation, development and maturation of blood cells in adult bone marrow
Where does haematopoiesis occur in adults?
Bone marrow
Name the parts that make up bone
- Non cellular mineralised matrix
2. Cells that maintain the matrix
What is the matrix that makes up bone made up of?
- Type I collagen- osteoid
- Calcium phosphate (calcium hydroxyapatite)
- Regulatory protein and growth factors
What is type 1 collagen in bone called?
Osteoid
List the cells that maintain the matrix in bone
- Osteoblasts
- Osteocytes
- Osteoclasts
Why is mineralisation critical?
The osteoid would be soft and bendy if it wasn’t mineralised
What do osteoblasts do?
They build up the bone
What is the origin of osteoblasts
Mesenchymal origin
What is the function of osteoblasts?
- They secrete osteoid
2. Needed for mineralisation
What are osteocytes
Inactive osteoblasts that are trapped in the bone
What is the origin of osteoclasts
Macrophage lineage
What do osteoclasts do?
They are involved in bone resorption and remodelling
How can bone be categorised?
- Maturity type
2. Location type
Name the different types of bone based on maturity
- Woven bone (immature bone)
2. Lamellar bone
Describe woven bone
It is immature bone as the osteoid collagen is random
It is remodelled into lamellar bone
What causes the random osteoid formation in woven bones?
Rapid bone turnover by osteoblasts
What is woven bone remodelled into?
Lamellar bone
Where is woven bone found?
In fractures
Fetal developemt
Describe lamellar bone
Made up of parallel bands/ sheets of lamellae