Term
| Where does the lower limb develop? |
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Definition
| Begins with activation of a group of mesodermal cells of the lateral plate mesoderm. Migrate to limb bud and condense along central axis to form vasculature and skeletal components. |
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Term
| Where do the musculature components of the lower limb migrate from? |
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Definition
| Mesoderm from the somites. |
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Term
| What gene do the future limb mesodermal cells express? |
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Definition
| Homebox 3.3 which is expressed before there any hint of limb bud formation. |
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Term
| What function does the Limb mesoderm perform? |
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Definition
| It signals ectoderm at the tip of the limb bud to thicken and form the apical ectodermal ridge (AER) |
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Term
| What function does the Apical ectodermal ridge perform? |
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Definition
| it interacts with underlying mesoderm to promote outgrowth of the limb bud by promoting mitosis and preventing terminal differentaition of mesodermal cells at the tip of the limb bud. |
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Term
| Zone of polarizing activity |
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Definition
| Mesodermal cells located at the base of the limb bud. Directs the organiztion of teh limb bud and patterning of the digits, both of which involve retinoic acid and homeobox gene Hox-4 |
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Term
| What cellular process causes digit formation and what layer does it occur in? |
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Definition
| Apoptosis within the AER such that five separate region of AER remain at the tips of the future digits. |
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Term
| What artery gives rise to the axis artery? |
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Definition
| Umbilical artery which ends in a terminal plexus near the tip of the limb bud. |
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Term
| What does the terminal plexus of the Axis artery do? |
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Definition
| It participates in the formation of hte deep plantar arch. |
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Term
| What are the 5 portions of the Axis Artery? |
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Definition
| 1. A. Tibial artery 2. P. Tibial artery 3. Inferior Gluteal Artery 4. Proximal part of the Popliteal Artery 5. Distal part of the peroneal artery. |
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Term
| External Iliac Artery derivatives |
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Definition
| 1. Femoral Artery 2.Profunda Femoris Artery |
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Term
| What bones are formed from the Lateral Plate Mesoderm? |
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Definition
| Everything south of the border from the Ilium down to the phalanges. |
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Term
| What type of ossification do the bones of the lower limb undergo? |
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Definition
| Endochondral ossification. |
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Term
| Where is the upper limb bud located and where does it migrate to? |
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Definition
| It lies opposite somites L1,L2,L3,L4,L5,S1,S2. Mesoderm from these somites migrate to the limb bud and forms a posterior condensation and an anterior condensation. |
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Term
| Where do the nerves for the lower limb develop from? |
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Definition
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Term
| How are the early nerve fibers guided? |
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Definition
| Are guided into the limb bud by local cell biological messages at its base; the muscles themselves do not provide any specific target messages to the ingrowing nerve fibers. |
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Term
| What week do the lower limb buds appear? |
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Definition
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Term
| How many degres does the lower ilmb rotate? |
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Definition
| 90 degrees Medially during weeks 6 to 8 such that the elbow points posteriorly. |
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Term
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Definition
| usually genetically inherited as an autosomal dominant trait resulting in multiple toes |
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Term
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Definition
| Failure of differentiation in which the fingers fail to separate into individual appendages. |
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Term
| When does separation usually occur? |
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Definition
| During the sixth and eighth weeks of embryological development. |
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Term
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Definition
| a condition in which two or more of the fingers or toes are joined together that can involve the bones or just the skin between the digits. |
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Term
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Definition
| Foot turns inward and points downward. Restrict lower leg outward movement and causes foot to turn inward. |
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Term
| What is the cause of Teratologic Clubfoot? |
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Definition
| Occurs as a part of an underlying neuromuscular disorder, such as spina bifida |
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Term
| Syndrome Complex Clubfoot |
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Definition
| occurs when a child is born with one of a number of genetic disorders. Children with chromosomal abnormalities such as Down Syndrome. |
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Term
| What is the etiology of Positional Clubfoot? |
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Definition
| When clubfoot occurs when an otherwise normal foot is held in a deformed position in utero, and is molded incorrectly. Small uterus, presence of twins and abnormal fetal position have been associated with positional clubfoot. |
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Term
| What are the symptoms of congenital dislocation? |
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Definition
| Reduced movement in the affected side. leg may seem shorter. assymetric. after 3 months of age leg may turn outward or be shorter than the other leg. |
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Term
| What is the treatment of Congenital dislocatino of the hip? |
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Definition
| Early infancy, positioning with a device to keep the legs apart and turned outward will usually hold the hip joint in place. |
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