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Related Flashcards
Cards In This Set
| Front | Back |
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Embryology
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Study of origin and development of single individual
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Prenatal Period
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-Embryonic period - first 8 weeks (2 months)
-Fetal period - 9 weeks to birth |
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Week 1: Embryonic Period
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-Zygote
-4-cell -Morula solid cluster of 12-16 cells -Early blastocyst -Late blastocyst |
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Trophpblast
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Helps form placenta
-allows to interact with mother and get nutrients |
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Week 2: Two Layered Embryo
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Bilaminar embryonic disc: inner cell mass divided into
-Epiblast -Hypoblast |
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Week 3: 3 Layered Embryo
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-Primitive streak: raised groove on dorsal surface of epiblast
-Gastrulation |
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Gastrulation
Week 3 |
Process of the embryo growing from two-layered disc (with epiblast and hypoblast layers) to three-layered disc with three germ layers which all derived from epiblast
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Week 3: Germ layers form
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-Form 14-15 days when primitive streak appears on dorsal surface of epiblast
-Epiblast migrate inward through hypoblast layer to become endoderm -Day 16 - epiblast cells form mesoderm (between epiblast and endoderm) |
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Epiblast
Week 3 |
Form all 3 primary germ layers
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Endoderm
Think: Replace Week 3 |
Formed from migrating cells that replace hypoblast
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Mesoderm
Think: Between Week 3 |
Formed between epiblast and endotherm
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Ectoderm
Think: Stay Week 3 |
Formed from epiblast cells that stay on dorsal surface; formed from surface epiblast
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Primitive Node
Week 3 |
Swelling at one end of primitive streak
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Notochord
Week 3 |
-Rod appears on day 16 and develops from primitive node and is made up of mostly mesodermal cells and some endodermal cells
-Defines body axis and forms midline that divides left/right sides of body -Extends length of body and is future site of vertebral column |
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Week 3: Neuralation
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As notochord develops, it signals surrounding ectoderm to start forming brain and spinal cord
-Neural plate -Neural groove |
