(P) Lec 5: Bones and Cartilages Flashcards
Familiarize the functions of the bones
- Provides solid support for the body
- Protects vital organs
- Attachment for muscles, tendons, and ligaments
- Acts as levers by which movement is produced
- Reservoir of calcium, phosphate & other ions
These are:
- Undifferentiated cells capable of mitosis
- Mesenchymal stem cells
- Potential to proliferate and differentiate
into osteoblasts - Role in bone growth and repair
Osteoprogenitor Cells
Where did osteoprogenitor cells develop from?
Embryonic tissue
What does osteoblasts synthesize?
Osteoid
Main function of osteoblasts?
Bone formation
Where are osteoblasts found?
Lining surfaces of the bone matrix
Two types of osteoblasts
Active and Inactive
Osteoblasts that are cuboidal or columnar with basophilic cytoplasm
Active
Osteoblasts that are flat cells that line the endosteum and periosteum
Inactive
These are:
- Mature cells
- Flat, almond-shaped
- With cytoplasmic processes
- Found in cavities (lacunae)
- Between bone matrix layers (lamellae)
- Maintain bone matrix
Osteocytes
Where are osteocytes found?
Lacunae
The communication in osteocytes are through what?
Canaliculi
What is the main function of the osteocytes?
Maintains the bone matrix
These are:
- Motile, multinucleated giant cells
- Fusion of bone marrow derived cells
- Role in matrix resorption
Osteoclasts
Where do osteoclasts lie?
Within the resorption lacunae
The resorption lacunae is also called what?
Howship’s lacunae
These are produced by the fusion of bone marrow-derived monocytes
Osteoclasts
These erode the bone matrix during remodeling
Osteoclasts
What is the main function of the osteoclast?
Bone resorption
The Bone matrix is composed of what two part?
Inorganic and Organic
This makes up 50% of the bone matrix
Inorganic and Organic (they’re both 50%)
What is most abundant in the inorganic part of the bone matrix?
Calcium hydroxyapatite
This is also composed of Bicarbonate, citrate, magnesium, potassium, sodium ions; Calcium phosphate
Bone Matrix - Inorganic
The organic part of the bone matrix is composed of what type of collagen?
Type I