Term
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Definition
Shows up between days 15-18
-Establishes axes
-Has Primitive node, groove, and pit
-Formed from interactions at caudal end |
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Term
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Definition
-An epiblast cells becomes a bottleneck cell, and then a mesenchymal cell
-Cells invaginate through the primitive streak. |
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Term
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Definition
Epiboly- spreading of epithelial sheet
Emboly-internalization
Convergence-movement toward midline
Extension-lengthening in cranial-caudal plane |
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Term
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Definition
| Cells have a monocilium which rotate and create a leftward flow, thought to establish asymmetric distribution |
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Term
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Definition
Happens on days 14-15
-Epithelial to mesenchymal transformation (EMT)
-Replace hypoblast cells. |
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Term
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Definition
-Starts on day 16
-Cells go between epiblast and endoderm, reform to make cardiogenic, paraxial, intermediate, and lateral |
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Term
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Definition
| -Starts as hollow tube, fuses w/endoderm, emerges as a solid chord |
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Term
| Paraxial Mesoderm- 2 main segments |
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Definition
-Head region- unsegmented, forms muscles of face
-Trunk- segments into somites, uses notch signaling, 42-44 pairs. becomes vertebrae, etc. |
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Term
| Lateral Plate mesoderm-Day? |
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Definition
Only forms in trunk
Splits at day 17 into:
Splanchnic- gut lining
Somatic-inner lining of body wall |
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Term
| Neural Plate formation-day? |
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Definition
-Forms on day 18 cranial to primitive node
- Develops cranial->caudal due to Bmp antagonists
-Will fold in the 4th week to form neural tube. |
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Term
| 4 Steps of Neural tube formation |
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Definition
1-Neural plate thickens
2-neural plate elongates
3-lateral folding w/ lateral/median hinge points
4- Fusion w/opposing folds. leaves neural crest cells |
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Term
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Definition
-The forming of neural tube in the sacral/coccygeal sections
- A medullary cord develops, then a lumen, then it merges with the cranial neural tube. |
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Term
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Definition
-Happens in 1/1000 live births
-Craniorachischisis-entire length is open
-spina bifida aperta-lower region is open
-Anencephaly- open at cranial end, no brain |
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Term
| Myelomeningocele vs meningocele |
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Definition
| Both are a bulge out of the spine, myelomeningocele is when the spinal cord is in the bulge. |
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Term
| What becomes the diaphragm? |
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Definition
| The septum transversum, which also creates a barrier between the abdominal and thoracic cavities. |
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Term
| Anterior body wall defects |
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Definition
Omphalocele-bowel is covered
Gastroschisis-bowel protrude out of body wall
Ectopia Cordis- heart forms outside of body |
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Term
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Definition
| -Most glands, respiratory, liver, ant. pit. |
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Term
| Week 4 external appearance |
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Definition
-C-shaped
-No limbs, no urogential system
-oropharyngeal membrane breaks down. |
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Term
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Definition
| Swelling of mesoderm that will become specific structures, ie. maxilla or hyoid |
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Term
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Definition
-Vestigial for nutrition
-PGC and blood islands |
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Term
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Definition
-Wraps embryo and provides protection
-single layer of ectodermal cells |
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Term
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Definition
Chorionic Plate-surrounds the chorionic cavity
Chorionic Cavity- contains the embryo/amnion |
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Term
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Definition
1-Primary villus of cytotrophoblast extension
2-secondary villus adds mesenchyme core
3-tertiary villus- maternal blood vessels |
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Term
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Definition
-From the mother
-Decidua capsularis-opposite of fetus, on chorionic vessle
-Decidua basalis-embryo side, becomes placenta
-Decidua parietalis- endometrium of uterus |
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Term
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Definition
Chorion frondosum-decidua basalis, becomes placenta due to blood availability
Chorion Laeve-smooth chorion, fusion of capsularis and parietalis |
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Term
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Definition
-Derived from body stalk
-Bathed in Warton's Jelly (CT)
-2 arteries, one vein |
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Term
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Definition
- Monosomy X
-Short stature, webbed neck, streaked ovaries. |
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Term
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Definition
Keratinocytes-multilayered ectoderm
Langerhaun's- immunity, from bone marrow
Melanoblasts-pigment cells, from NCC
Merkel Cells- mechanoreceptors, probably NCC |
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Term
| Sweat and Sebaceous glands |
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Definition
Sweat- bud off from statum germinativum, unbranched and coiled
Sebaceous-bud off from hair follicle |
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Term
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Definition
-Caused by dermal induction
-a hair peg forms- epidermal downgrowth
-follicle/dermal papilla
-2 bulges-arrector pili, sebaceous gland |
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Term
| Differentiation of the sclerotome |
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Definition
| -Ventral portion surround notochord and forms vertebral body -Dorsal portion forms vertebral arch/spine -Lateral portion from ribs |
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Term
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Definition
Dense caudal half and loose cranial half
-4 most cranial fuse to make occipital bone
-8 cervical somites, one fuses w/occipital, leaving 7 cervical |
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Term
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Definition
Notochord persists as nucleus pulposus
Sclerotomal cells form annulus fibrosus |
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Term
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Definition
-Surrounds skull
-Chondrocranium:occipital, sphenoid, temporal
-Membranous neurocranium-frontal/parietal
-Composite-occipital/temporal add membranous bone during dev. |
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Term
| Grebe type chondrodysplasia |
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Definition
-shortening of appendicular skeleton
-mutation in GDF5 (size/proliferation)
-limb skeleton w/increasing severity proximal to distal |
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Term
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Definition
-Most common form of dwarfism
-all endochondral bones affected
-mutation in fibroblast growth factor 3
-decreased chondrocyte proliferation |
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Term
| What induces limb growth? |
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Definition
| -FGF10 induces the nearby ectoderm |
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Term
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Definition
| region of embryo that will give rise to the limb |
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Term
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Definition
-Apical ectodermal ridge
-multilayered ectoderm
-interacts with mesoderm core to bring about limb
-limb grow proximal to distal |
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Term
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Definition
-Somatic-skeleton
-Somitic-muscle
-NCC-schwann cells and melanocytes |
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Term
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Definition
| -Cartilage formation and vasculature. |
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Term
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Definition
-leave before closure of NT
-tissues in the face |
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Term
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Definition
-2 paths
-Vagal-gut/parasympathetic innervation
-Cardiac-heart vessels, thymyus,thyroid |
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Term
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Definition
-Leave after NT closes
-3 pathways
-Dorsolateral-melanocytes
-Ventrolateral-sensory ganglia
-Ventral-adrenal stuff |
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