MSK 1 Flashcards
Components of skeletal system
Osseous tissue
Cartilage
Dense CT
Marrow
Neurovasculature
Osseous tissue
Mineralized CT
Organic = collagen - flexibility
Inorganic = minerals - hardness
Cartilage
Mostly hyaline
Function as joints or bone ossification
Avascular
Dense CT
Periosteum
Tendons
Ligaments
Marrow
Yellow and red
Yellow bone marrow
Stores adipocytes, supports blood vessels and cells
Red bone marrow
In fetus and first few years
Hemopoietic - blood forming
Later become yellow marrow
Some stay red like spine, sternum, wrists
Neurovasculature
Arteries - carry oxygenated blood away from heart
Veins - carry deoxygenated blood back to heart
Tensile strength/force
Stretching
Compressive strength/force
Compressing
Shear strength/force
Pulling in opposite directions
Axial skeleton
Bones in center/midline of body such as spine, neck, head, pelvic
Appendicular skeleton
Limbs
Come out from middle
Long bones
Articular cartilage
Ephysis
Metaphysis - contain ephyseal plate/line
Diaphysis
Periosteum
Medullary cavity
Endosteum
Diaphysis
Shaft of bone
Ephysis
Ends of bone
Metaphysis
In between diaphysis and ephysis
Ephyseal plate
Starts as hyaline cartilage joint - synchondrosis
Allows growth
With age become ephyseal line
Articular cartilage
Thin layer of hyaline. remaining after cartilage model bone ossification
Periosteum
Outer surface of bone with inner osteogenic layer and outer fibrous layer
Medullar cavity
Contains bone marrow and blood vessels
Endosteum
Layer of cells lining medullary cavity and trabeculae
Cells associated with osseous tissue
Osteogenic cells
Osteoblasts
Osteocytes
Osteoclasts
Osteogenic cells
Bone stem cells derived from mesenchyme, able to divide, later become osteoblasts
Osteoblasts
Build bone, create collagen fibers
Osteocytes
Maintain metabolism
Osteoclasts
Consume bone through releasee of enzymes and acids
Formed through fusion of WBC
ECM
Surround cells
Mineral (hydroxyapatite) + collagen fibers + water
Compact bone
Bending strength
External layers
Mostly diaphyses
Cortical, dense
Spongy
Compress strength
Internal filling
Mostly short, flat bones
Trabecullar, cancellous
Compact bone features
- organized as osteons along lines of stress
- concentric lamallae
- perforating canals around neurovasculature
- circumferential lamellae line
Spongy bone features
- Made up of trabecullae along lines of stress
- Contain concentric lamellae and osteophytes
- Large space filled with bone marrow
Bone formation
Around 6 weeks, from mesechymal skeleton
Intramembraneous ossification vs endochondral ossification
Intramembraneous ossification
Mesenchyme to bone
Mostly for flat bones of skull, facial, mandible, clavicle
Widening and thickening
Endochondral ossification
Mesenchyme to cartilage model to bone
Most bones from this way
Ossification
Formation of bone
Cartilage model
Chondroblasts create hyaline cartilage
Interstitial growth
Growth from within, length wise
Appositional growth
Growth from outer surface, thickness
Bone remodeling
Balance between osteoblasts and osteoclasts
Minerals
Calcium and phosphorous - minerals, hardness
Vitamin D
Calcitriol - helps absorption of calcium
Vitamin C
Important for collagen synthesis
Calcitonin
Decrease blood calcium, inhibits osteoclasts, activates osteoblasts
Parathyroid hormone (PTH)
Increase blood calcium, inhibit osteoblasts, activate osteoclasts
Sex hormones
Promote bone lengthening
Human growth hormone
Overall bone growth
Types of fractures
Open vs closed
Comminuated
Impacted
Greenstick
Comminuated fracture
Crumbled or shattered
Impacted fracture
Bone pressed into each other
Greenstick fracture
Partial, juvenile
Repair of fracture
Open reduction = surgical
Closed reduction = manual
Aging of osseous tissue
Decreased minerals - loss of bone mass
Decreased collagen - brittleness
Osteoporosis
reabsorption > deposition
bone pain, easier to fracture
Osteoporosis risk factors
Older women
Smaller build
Sedentary lifestyle
