The Skeletal System 1 Flashcards
List 5 functions of the skeleton…
- Structural support,
- Protects internal organs,
- Provides leverage for movement,
- Stores calcium,
- Produces blood cells.
Bone is dynamic… What does this mean?
It changes as it is living tissue.
Bone is a specialised form of what type of tissue?
Connective.
Why does bone need to be strong and flexible?
To carry body weight.
What is the organic component within the bone matrix?
Osteoid - made up of collagen and polypeptide chains.
List some properties of the organic component of bone matrix…
Strong, Flexible and easily compressed.
What is the inorganic component within the bone matrix?
Hydroxyapatite - deposition of mineral salts, mainly calcium phosphate and calcium carbonate.
List some properties of the inorganic component of bone matrix…
Hard, Inflexible and brittle.
What is an osteoblast?
They produce new bone - secrete osteoid and are responsible for mineral deposition.
What are osteocytes?
Mature osteoblasts - Located within lacunae, maintain the matrix.
What are osteoclasts?
Remove minerals from the matrix - responsible for bone remodelling.
What are osteogenic stem cells?
Found in periostem and endosteum - Develop into osteoblasts.
What are the 2 types of bone tissue?
- Compact bone - Located on the surface of the bone.
2. Cancellous bone - Located on the interior of the bone.
Compact bone is structured to…
Resist stresses.
What are lamellae?
Rings of bone wrapped around canal.
What are trabeculae within cancellous bone?
A framework of small rings of bone
What do the spaces between the trabeculae in cancellous bone contain?
Bone marrow where new blood cells are made.
What is myeloid tissue?
Red bone marrow
What is yellow bone marrow?
Fatty tissue that no longer produces blood cells.
How is flat bone structured?
Cancellous bone surrounded by compact bone.
What are the 2 methods of bone formation?
- Intramembranous ossification,
2. Endochondral ossification.
What are the 3 stages of Intramembranous ossification?
- Mesenchymal cells secrete osteoid. Deposition of calcium salts leads to calcification.
- Blood vessels grow into area and supply nutrients and oxygen.
- Initially only cancellous bone is formed but remodelling occurs and compact bone is formed.
What happens during Endochondral ossification?
Cells start to become bone rather than cartilage.
What is an epiphyseal line?
Where 2 bones meet where there used to be an epiphyseal plate.
What are the 3 stages of bone remodelling?
- Calcium salts are deposited and reabsorbed as required
- Bone is thickened to increase strength.
- Old bone is renewed and injured bone is replaced.
What symbol is used to indicate the term fracture?
Hash symbol.
What are the 2 types of fracture?
- Compound - Breaks the skin, bone protrudes through skin.
2. Simple - Bone is contained within skin.
List 6 classifications of fractures…
- Greenstick - bends and cracks (only in children)
- Comminuted - 2 or more broken pieces
- Linear - Runs down the bone
- Transverse - Broken straight across the bone.
- Oblique - Slanted fracture
- Spiral - Bone has been twisted apart.
What are the 4 stages of bone healing?
- Haematoma formation.
- Area is invaded be capillaries, fibroblasts, osteoclasts and osteogenic cells and a soft callus forms.
- Soft callus is hardened by mineral desposition.
- Remodelling by osteoclasts occurs.
How long does it take for a bone to heal?
8 weeks - depending on good blood supply and freedom from infection.
List 5 factors that delay bone healing?
- Deficient blood supply
- Tissue fragments between bone ends
- Poor alignment of bone ends
- Continued mobility of bone ends
- Infection
Functional classification of joints…
- Synarthrosis - little or no movement
- Amphiarthrosis - slightly moveable
- Diarthroses - freely moveable
Structural classification of joints…
- Cartilaginous - bones held together by cartilage
- Fibrous - Bones held together by collagenous fibres.
- Synovial - Bones separated by a joint cavity and enclosed in a fibrous capsule.
