to do list for today functions of the skeleton bone shapes general features of bone – parts bone...
Post on 21-Dec-2015
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To do list for today
• functions of the skeleton• bone shapes• general features of bone – parts• bone histology = cells + matrix• Vitamin D, calcium & bones• structural disorders of bone
• osteoporosis
long short flat irregular
Fig. 6.2a(TE Art)Epiphysis
Epiphysis
Diaphysis
Spongy boneEpiphyseal line
Compact bone
Medullary cavity
Endosteum
Articular cartilage
Periosteum
Articular cartilage
osteo = boneperi = aroundendo = withinartic = joint
Compactbone
SpongyBone(diploe)
Suture
Flat bones
Bone tissue = bone cells = matrix
periosteum
endosteum
osteon
Central canal
trabeculae
Perforating canal
Perforating fibers
Compact boneSpongy boneBone marrow
Osteoprogenitor
** osteocyte **
** Osteoblast **
Bone cells
canaliculi
Stem cells
osteoclast
Bone dissolving macrophages** Osteoclast **
Why dissolve bone??
Paget’s disease (osteitis deformans) = increased osteoclast activity
Bone matrix
• 1/3 organic = flexibility• collagen• protein-carbo complexes
• 2/3 inorganic = strength• calcium phosphate salt• magnesium, sodium, potassium…•Osteogenesis imperfecta = impaired osteoblast function, collagen unorganized, brittle bones
Calcium and vitamin D• need vitamin D to absorb calcium in the small intestine• need UV to make vitamin D• osteomalacia (rickets) = deficient vit D, soft bones
Shell-less chickno calcium, no ossified bone
Bone deposition = resorption
Osteoporosis = porous bones
• decreased deposition• increased resorption• spongy bone affected
• bones become brittle• women > men
• less bone mass• lose it earlier & faster• decrease in estrogen
• build bone mass ???!
Drink milk?What about my latte milk?Does that count?
Things that affect bone resorption or deposition:• corticosteroids – reduce osteoblast activity (matrix synthesis) increase osteoclast activity• estrogen & testosterone – increase osteoblast activity• caffeine – binds Ca so it’s excreted• smoking – decrease osteoblast production, impairs Ca absorption, interferes with ERT
www.pdrhealth.com/
Osteoporosis and Anatomy….
Areas with more spongy bone
kyphosis
Hip fracture complications