Term
| When does the limb bud appear? |
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Definition
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Term
| What happens around week 5 to the limb bud? |
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Definition
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Term
| When do elbows become visable? |
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Definition
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Term
| What is (are) present at the end of week 8? |
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Definition
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Definition
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Definition
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Definition
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Term
| How do gene products that regulate differentiation get to limb bud? |
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Definition
| The buds are small enough so cell surface interactions can occur. |
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Term
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Definition
- anterior to posterior at distal margin of bud
- produces fibroblast growth factors (FGF)
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Term
| Zone of polarizing activity |
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Definition
- mesenchyme at posterior margin
- expresses "Sonic Hedgehog" Shh
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Term
| Fibroblast growth factors |
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Definition
| keeps undifferentiated mesenchymal cells undifferentiated and proliferating in the "progress zone" |
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Term
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Definition
- mediated polarizing activity
- causes pattern development along AP axis
- FGF promtes Shh expression by ZPA
- determines location of hand, and little finger
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Term
| What growth factor does mesenchyme express? |
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Definition
| En1, which regulates dorsal ventral development |
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Term
| What determines the themes of the other digits? |
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Definition
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Term
| What plays a role in the structural conformation of the humerus, forearm, wrist |
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Definition
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Term
| Describe cartilage formation? |
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Definition
- mesenchymal cells condense to form prechondrogenic columns along P-D axis, which then differentiate into chondrocytes
- ECM is typeII and aggregan
- chondrocytes forms perichondrium which produces bone morphogenic protein and parathyroid hormone (will regulate growth and differentiation of cartilage and bone)
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Term
| Describe endochondral ossification |
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Definition
- cartilage is template for bone
- periosteum prevents diffusion to chondrocytes, they die make lacunae
- lacunae forms path for vasculature and osteocytes to enter
- Osteocytes lay down bone matrix, then ossifies
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Term
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Definition
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Term
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Definition
partially absent limb week 5-6 |
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Term
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Definition
small, irregular limb week 5-6 |
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Definition
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Definition
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Definition
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Term
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Definition
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Term
| hand-foot-genital syndrome |
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Definition
fusion of carpal bones-short digits HOXA13 mutation |
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