Musculoskeketal 1 Flashcards
What makes up the adult skeleton?
Axial
Appendicular
How many bones in the axial skeleton?
80 (some pairs)
How many bones in the appendicular skeleton?
126 (all paired)
Function of axial skeleton?
Support/protection
Haemopoiesis (red bone marrow)
Function of appendicular skeleton?
Movement Fat storage (yellow bone marrow)
Two meanings of bone?
- Bone the organ (organs made up of different types of tissues)
- Bone the tissue (one of the tissues found in the bones of the skeleton)
Function of the skeletal system?
- Support
- Protection
- Movement
- Calcium and phosphorous reserve
- Haemopoiesis
- Fat storage
Thin inner fibro-cellular layer lining the medullary cavity?
Endosteum
Inside of bone?
Medullary cavity
Outer fibro-cellular sheath surrounding the bone?
Periosteum
Parts of the extra cellular matrix?
Fibres (organic) Ground substance (inorganic)
What type of fibres are in extra cellular matrix?
Collagen fibres type I and V
Purpose of fibres in ECM of bone?
To resist tension (stretching/pulling)
What type of tissue is bone?
Specialised connective tissue
What is the main component of ground substance?
Hydroxyapatite (Ca10(PO4)6OH2)
Purpose of ground substance?
To resist compression (squeezing, crushing)
Types of cells in bone?
Osteogenic
Osteoblasts
Osteocytes
Osteoclasts
Purpose of cells in bone?
Cell reserve
Bone formation
Bone maintenance
Bone destruction
What do the combination of fibre (tension) and ground substance (compression) result in?
Torsion
What is the precursor to osteogenic cells?
Unspecialised stem cells (mesenchyme = embryonic CT)
What are known as osteoprogenitor cells?
Osteogenic cells
What is the location of osteogenic cells?
Surface of bone in the periosteum and endosteum. Also found inside canals of compact bone
What is the function of the osteogenic cell?
They’re normally dormant but can divide and supply developing bone with bone-forming cells
What is the precursor of an osteoblast?
Osteogenic cell
Where is the location of the osteoblast?
Usually in a layer under the Peri or endosteum. Wherever new bone is being formed
What is the function of the osteoblast?
Synthesis, deposition and mineralisation of osteoid
What is osteoid?
The organic extra cellular matrix (mainly collagen) of bone, synthesised by osteoblasts prior to mineral deposition
What is the composition of osteoid?
70% collagen, remainder is proteoglycans and other proteins
What happens to the precursor osteoid matrix?
It’s eventually infiltrated with bone salts (hydroxtlyapatite)
What’s the infiltration of the precursor osteoid matrix with bone salts called?
Calcification
What does calcification do to osteoid?
It makes the bone strong but dense, thus nutritive fluids cannot diffuse freely through it
What is the precursor to osteocyte?
Osteoblast
Where is the osteocyte located?
Trapped within lacunae inside bone.
How do osteocytes communicate with neighbouring cells?
Through their long cellular processes and canaliculi
Function of osteocytes?
Bone tissue maintenance
Precursor of osteoclasts?
Fusion of monocyte (white blood cell) progenitor cells (Syncytium)
Location of osteoclasts?
At sites where bone resorption is occurring (wherever you want to get rid of bone)
Function of osteoclasts?
Secretes acid and enzymes to dissolve the mineral and organic components of bone
