MSK Flashcards
What are bones composed of
Nervous tissue
Muscle and epithelial tissue
Connective tissue (osseous tissue
Osseous tissue
Connective tissue that contains specialised cells and an extracellular matrix
Extracellular matrix
Ground substances
Collagen fibres (flexibility and tensile)
Calcium phosphate crystals (hard and compressive)
Specialised cells of osseous tissue
Osteoprogenitors cells
Osetoblasts
Osteoclasts
Osteocytes
Osteoprogenitors cells
Stem cells that differentiate into osteoblasts
Osteoblasts
BUILD
Produce and secrete collagen fibres and ground substance = matrix
Osteoclasts
REABSORBING
Break down the matrix and release stored minerals
Osteocytes
MAINTAIN
Mature bone cells that maintain the matrix
Compact bone
Outer layer of bone arranged into osteons = resist force applied to ends
Periosteum
Outer connective tissue membrane of compact bone
Spongy bone
Internal layer of bone arranged into trabeculae = resist forces from all directions
Endosteum
Internal connective tissue membrane of spongy bone
Interstitial growth
LENGTHENS
Occurs at the epiphyseal plates of long bones.
Appositional growth
WIDENS
Occurs at the outer surface of all bones
Types of cartilage
Hyaline = most abundant (epiphyseal plates) Elastic = forms shape of structure Fibrocartilage = highly resilient to pressure, high strength
End of bone
Epiphysis
Shaft
Diaphysis
What comprises central canal of bone?
Nerve
Artery
Vein
End of bone growth
Epiphyseal plate closure
Rate of bone formation exceeds rate of cartilage formation; cartilage replaced by bone = epiphyseal line
Purpose of bone remodelling
Maintains bone mass and strength
Replaces old matrix with new matrix
Bone resorption
Osteoclasts breakdown old matrix
Bone deposition
Osteoblasts produce new matrix
Steps of fracture repair
- Haematoma forms
- Fibrocartilaginous callus forms
- Bony callus of spongy bone forms (fibrocartilaginous callus is replaced by spongy bone)
- Bone remodelling
Osteomalacia (Rickets in children)
Bones are poorly mineralised → lack calcium phosphate crystals
Bones are soft, very flexible and easily deformed
Insufficient calcium intake or a vitamin D deficiency
Osteogenesis imperfecta (brittle bone disease)
Congenital bone disorder that affects the quantity and/or quality of collagen fibres
Bones are brittle and easily fractured
Osteoporosis
Bone resorption outpaces bone deposition - reduction in bone mass compromises normal bone function
Bones have normal matrix components, but in reduced amounts → bones are porous, light, fragile and easily fractured
Synarthrosis joint
Immovable
Amphiarthrosis joint
Slightly movable
Diathrosis joing
Freely movable
Stabilising features of a synovial joint
Reinforcing ligament
Muscle tendons
Articular capsule
Menisci
Friction reduction features of a synovial joint
Articular cartilage
Synovial fluid
Menisci
Bursa/tendon sheath
Fasicle
Group fo muscle fibres (endomysium)
Covered by perimysium
Muscle fibre
Group of myofibril
Covered by endomysium
Myofibril
Group of sarcomere
Covered by sarcolemma (PM)
Sarcomere
Composed of:
Contractile proteins -
Thick (myosin) and thin (actin)
