List the Four types of Bone Cell
Osteoblasts - Bone Building Cell
Osteocytes - Mature Bone Cells
Osteoclasts - Bone Reabsorbing Cells
Lining Cells - Line the surface of bone
What are Osteoblasts
- Cells responsible for the production of new Bone (process known as Osteogenesis)
- Present at sites where bone is growing, repairing and remodelling
- Osteoblasts deposit new bone tissue around themselves and eventually become trapped in tiny pockets known as Lucunae
- It is at this point that they diffrentiate into Ostoecytes (Mature Bone Cell)
What are Osteocytes
- Mature Bone Cells that do not divide
- Monitor and maintain mature bone tissue
- Detect mechanical strain
- Regulate the balance of calcium and Phosphate because they signal ostoeblasts
What are Osteoclasts
- Giant Cells with 50 or more nuclei
- Cells Break down releasing calcium and phosphate
- Help regulate calcium and phosphate concentrations in body fluids
- Found in areas of the bone where there is active growth
Osteoblasts are present at which sites of the Bone
- Periostium
- Each end of the Diaphysis of the long bone
- At Fracture sites
Osteoclasts are found in which parts of the bone
- Areas where growth and repair occur
- Periosteum - maintaining bone shape and removing excesss callus formed during fracture healing
- Medullar Cavity - during growth and canalising of the bone when healing
Describe what is meant by the bone matrix
Material between the living Bone cells
Organic material - Collagen
In organic Material:
* Calcium/bone salts
* Hydropoxyapitate crystals
What are Lining Cells
- Line the entire surface of the bone unless osteoid is present (unmineralized bone)
- Release of Calcium from bone
- Protects bone from chemical
- Can sometimes inhibit drugs from curing bone infection
What is osteoid
Unmineralized organic component of Bone matrix
Made up of Type 1 collagen and bone matrix proteins
Eventually undergoes calcification and mineralization to form lamelle/layers in the bone matrix (Part of mineralization/hardening of the bone)
What is the other name given to compact bone
Cortical Bone
What is the name of the intercellular bone constituent which consists of ground substance, collagen fibers and inorganic mineral salts
Bone Matrix
What are Interstitial lamellae
- Sit in between Osteons/Haversion systems
- extracellular matrix around the cells that gives compact bone its hardness and rigidity
Which bone cell has multiple nuclei
Osteoclast
