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 Diaphysis Spongy bone Epiphyseal line Compact bone Medullary cavity Endosteum Articular cartilage Periosteum Articular cartilage osteo = bone peri = around endo = within artic = joint

Compact bone Spongy Bone (diploe) Suture Flat bones

Bone tissue = bone cells + matrix

periosteum endosteum osteon Central canal trabeculae Perforating canal Perforating fibers Compact bone Spongy bone Bone 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

Osteoporosis and Anatomy…. kyphosis

Hip fracture complications Think about this: What are some treatments for osteoporosis and which one(s) would you choose?