• Be sure to read the vitamin D article• Did you complete the lab survey yet?• Have you registered your clicker?
Bone Tissue
To do list for today
•general features of bone – parts• bone histology = cells + matrix• Vitamin D, calcium & bones• structural disorders of bone
• osteoporosis
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??
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 UVB to make vitamin D
Deficient levels of vitamin D can cause soft bones. True or False Osteomalacia (rickets) = deficient vit D, soft bones
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 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….
kyphosis
Hip fracture complications
Think about this:What are some treatments for osteoporosisand which one(s) would you choose?