A&P - Chapter 11 (Part 5) Flashcards
What do osteoblasts form?
Bone matrix
What do osteoblasts secrete?
Collagen fibres
What do osteoblasts initiate?
The process of calcification
What do osteoblasts develop into?
Osteocytes
Where are osteoblasts found? (2)
- Periosteum
2. Endosteum
What do osteoclasts do?
They are huge cells that digest bone matrix
- bone resorption
What are osteoclasts part of? (4)
- Normal bone growth
- Development
- Maintenance
- Repair
Where are osteoclasts concentrated?
In the endosteum
What do osteoclasts secrete?
Digestive enzymes to digest the bone matrix
What type of bone cell are osteocytes?
Mature bone cells
What do osteocytes no longer secrete?
Matrix
What are osteocytes responsible for?
Maintaining the bone
What do osteocytes regulate?
The amount of Ca deposited on the matrix
Where are osteocytes located?
Within lacunae
What are newborns skeleton made up of?
Many bones made of cartilage and other fibrous material
What has not fully happened to newborns bones?
They have not completely ossified
How long does it take for newborns bone material to get replaced by calcified bone matrix and osteocytes?
8 weeks
- 2 months
How do most bones in the body develop?
Through the process of endochondral ossification
Endochondral ossification
Bone formation in cartilage
- replacing cartilage tissue with bone tissue
What is the healing period of newborns?
Very fast
- very flexible
What does growth in bone length lead to?
It increases the length of the shaft
What needs to remain between the epiphyses and the diaphysis in order for growth to continue?
Epiphyseal plate
What does the epiphyseal line mark?
Where the two centres of ossification have fused together
