Term
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Definition
1. Fertilization
2. Cleavage
3. Gastrulation
4. Organogenesis |
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Term
| Describe the events of fertilization |
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Definition
1. Sperm penetrates cellular & glycoprotein coverins of egg
2. Sperm contacts & fuses with cell membrane
3. Sperm acrosome opens, sperm can penetrate egg membrane
4. Nucleus is released into the egg cytoplasm
5. Zygote formed, first mitotic division occurs |
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Term
| Where does fertiization occur |
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Definition
| ampulla region of oviduct |
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Term
| What layers of an oocyte must sperm penetrate? |
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Definition
1. Cumulus oophorous
2. Corona radiata
3. Zona pellucida
4. Plasma membrane of the egg itself |
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Term
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Definition
| sperm gains the abilityto swim rapidly, happens in the oviduct |
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Term
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Definition
first event after fertilization, rapid series of cell division that convert the zygote (unicellular) to an embryo (multicellular)
NO GROWTH AT THIS TIME |
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Term
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Definition
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Term
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Definition
Once embryo has 8 cells, outer cells adhere tightly together and form a morula
-mediated by E-cadherin which is a protein that causes cells to adhere tightly together |
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Term
| What are the early stages of embryo formation? (zygote et)q |
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Definition
Oocyte/Sperm
Zygote (1 cell)
Morula (8 cells)
Blastocyst (more cells) |
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Term
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Definition
| fluid secretes between inner blastomeres, driven by Na+, leads to formation of blastocele and inner & outer cell mass |
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Term
| What are inner & outer cell masses formed by cavitation? |
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Definition
inner - embryoblast
outer - trophoblast (will form fetal placenta) |
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Term
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Definition
division of inner cell mass into epiblast & hypoblast,
hypoblast cells spread along inside of blastocyst and form the primary yolk sac |
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Term
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Definition
| division of embryonic epiblast into ectoerm & primitive streak |
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Term
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Definition
| gene for forming fetal placenta |
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Term
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Definition
| directs cells to remain as pluripotent ICM cells |
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Term
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Definition
| maintains pluripotency of inner cell mass, so they can form pluripotent epiblast |
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Term
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Definition
| directs formation of the hypoblast |
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Term
| What is delamination / the bilaminar process? |
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Definition
ICM Nanog cells will form pre-epiblast
ICM Gata-6 will form pre-hypoblast
As embryo contacts endometrium, the hypoblastic cells will spread along the interior and form parietal endoderm & yolk sac |
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Term
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Definition
| converting the bilaminate epiblast into ectoderm, endoderm and mesoderm |
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Term
| What process initiates gastrulation? |
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Definition
Induction
-series of signals exchanged between the germ layers, resulting in the primitive streak forming along the posterior region of the embryo
-cells that enter primitive node first form notochord
-cells that enter the primitve streak first form endoderm
-later cells form mesoderm
-cells that dont enter ectoderm |
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Term
| The first cells to enter the primitive streak form... |
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Definition
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Term
| The later cells to enter the primitive streak form... |
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Definition
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Term
| Cells that don't enter the primitive streak form... |
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Definition
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Term
| After passing though the primitive streak, mesodermal cells spread _______ and form 3 regions of the mesoderm: |
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Definition
laterally
paraxial mesoderm (somites)
intermediate mesoderm (urogenital tract)
lateral plate mesoderm |
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Term
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Definition
| regions of paraxial mesoderm, they will form the various body segments |
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Term
| What are the 3 main body segments formed in somitogenesis? |
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Definition
myotome
dermatome
sclerotome |
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Term
| What 2 layers make up the lateral plate? |
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Definition
Somatic (form body wall & limbs)
Splanchnic (form heart, gut, viscera etc) |
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Term
| Deep to the primitive streak, a _____ forms between the hypoblast and epiblast. This will eventually become filled with ____ |
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Definition
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Definition
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