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32 Cards in this Set
- Front
- Back
what day is the 16 stage cell stage reached |
by end of day 3 |
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which cells give rise to foetal placenta and what day |
trophoblast cells by day 5 |
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which type of cells give rise to the embryo |
inner mass cells |
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by day 8 the cell mass differentiates into 2 what layers |
1. hypoblast (primative endoderm) 2. epiblast (primative ectoderm |
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what is the difference between pluripotent and totipotent cells |
totipotent cells can give rise an entire human being- cells that occur in early embryonic division pluripotent cells can give rise to all cells of the human body- derived from inner cell mass |
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by what day is 16-stage cell reached |
end of day 3 |
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which stage-cells holds totipotent cells |
4 and 8 |
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what's formed at day 5 |
blastocyst which consits of an inner cell mass and trophoblast |
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which cells give rise to the placenta |
trophoblasts |
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which cells develop into the embryo |
inner cell mass |
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day 6 |
Implantation - inner cell mass orientated to the uterine endometrium. The endrometrial gland enlarge and the endometrium, now known as the decidua becomes more heavily vascularised. |
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what happens on day 8 |
cell mass differentiates into 2 distinctive layers : 1) The hypoblast or primative endoderm 2) The epiblast, or the primative ectoderm |
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which two layers form the bilamiar embryonic disc |
hypo and epiblast |
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in what layer does the amniotic cavity form |
epiblast |
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which cells from the exocoelic membrane and how |
the hypoblast migrate and flatten and form the exocoelic membrane around the inner surface of blastocyst by day 9. |
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what happens at the same time as the formtion of the exocoelomic membrane |
the extention of the amnion cavity which surround the entire embryo forming the mbryonic cavity |
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what happens to the embryonic positioned between amniotic cavity and yolk sac in week 4 |
-cells in yolk sac develop into gonads and yolk sac develops into parts of the GI tract |
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whats a key developmental point in week 3 |
gastrulation |
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what happens in gastrulation |
Bilaminar disc develops into trilaminar structure, made of three primary germ layers |
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what does the ectoderm give rise to ? |
the skin and nervous system
(ect- sounds like exo so outside is skin , skin is sentive (nervous system) |
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what does the mesoderm give rise to |
muscle and bone (m for muscle) |
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what does the endoderm give rise to ? |
eepithelial lining of the GI tract and many organs
e for epithelial |
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what day does gastrulation start ? |
day 15 with migration of cells from epiblast forming the primative streak. |
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whats a primitive streak? |
roove on the dorsal surface of the epiblast that that extends from the posterior (tail region) to the anterior (node) region of the bilaminar disk. |
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what happens after the formation of the primitive streak |
After the formation of the primitive disk, epiblast cells migrate inwards below the primitive streak, some of which displace the hypoblast to form the endoderm, whilst other cells form the mesoderm The cells of the epiblast then form the ectoderm |
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what happens to mesodermal cells day 16 |
Day 16 mesodermal cells from the node migrate towards the head region of the embryo to hollow tube notochordal process, which then develops into turn the solid notochord |
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where does the oropharyngeal membrane form in week 3 ? |
forms on the dorsal surface of the anterior region of the embryo, and the cloacal membrane forms on the dorsal surface of the posterior (tail) region of the embryo. |
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in week 4 the oropharyngeal breaks down to form what ? |
to connect the oral cavity (mouth) to the pharynx and the GI trac |
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what does the cloacal membrane break down to form |
openings of the anal, urinary and reproductive parts |
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in what week does embryo undergo embryoninc folding |
4 |
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why does folding arise |
Folding arises because of unequal growth rates of different parts of the embryo. Folding in the medial plane gives rise to the head and the tail, whilst lateral folds give rise to the coelom and pinches off the yolk sac, giving rise to the primitive gut. |
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The primitive gut consists of three main regions, what are they |
the foregut, the midgut and the hindgut. |