Term
| where are ovaries and gonads forming? |
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Definition
| in the yolk sac. they have to send chemical recruitment signals to primordial germ cells telling them to enter the sex organs |
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Term
| when is meiosis 1 completed in women? what stage of meiosis WAS it and WILL it stall at |
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Definition
| it was arrested in prophase M1, will move forward at puberty during ovulation only to stall at P of M2 |
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Term
| what are the layers surrounding a mature oocyte? |
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Definition
zona pelucida (protective inner layer) and folliclar layer (outermost cells which responds to FSH)
the entire oocyte is called the cumulus oophorus when it has these two layers |
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Term
| difference between adult and embryonic stem cells? |
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Definition
adult stem cells can form any tissue within the family of cells they exist within and usually serve repair fxns
embryonic stem cells are pluripotent and can become anything when stimulated accordingly |
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Term
| a blastocyst as a two part outer layer. what are teh parts and what do they do? |
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Definition
cytotrophoblast: brings formation of primary villi. borders the amino sac, yolk sac, and is separated by the bilaminar disc
synctiotrophoblast: erodes away the materal tissue of the endometrium to expose lacunae which can pool blood and begin gas exchange with the mother. also part of villi formation and directly connects to placenta |
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Term
| where do all the layers of the trilaminar disc come from? what happens to the epiblast and hypoblast? |
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Definition
| All layers come from epiblast cells invading the space between the bilaminar disc. The epiblast will become the ecto, a mesoderm will begin to form, and then more cells will invade below the meso to form the endoderm. The hypoblast will degrade away, it is not destined to transform into one of the three layers. |
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Term
| what are some structures that arise from the ectoderm? |
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Definition
brain, nervous system, eyes, hair, skin
ecto "exterior" |
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Term
| what forms at the oropharyngeal membrane? |
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Definition
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Term
what forms at the cloacal membrane?
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Definition
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Term
what is the notochord's orginal purpose?
what does it become? |
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Definition
it is the central axis for the mesoderm
it becomes the nucleus pulpus which you find between the bodies of vertebrae |
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Term
| neural crest derivatives? |
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Definition
| flat bones of the skull, skin pigment, ear bones, adrenal medula, glial cells, schwann cells, preaortic ganglia, dorsal root ganglia |
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Term
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Definition
-paraxial: surroungs notochord, becomes somites and then sclero, dermo, and myotome. the sclerotome will being forming the vertebrae. the dermomyotome further differentiates into expaxial (back muslces) and hypaxial (everything else muslces)
intermediate: the mesonephric mesoderm. forms a lot of early reproductive tissues and a primitive kidney
-lateral plate: grows out from each side and encircles the gut by forming the coelum. the inner portion of this mesoderm becomes the splanchnopleure (visceral) and the outer portion becomes the somatopleure. the hypaxial mesoderm grows around the lateral plate mesoderm to form the muscles |
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Term
| where do bones and associated connective tissue develop from? |
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Definition
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Term
| what happens when endo and ectoderm meet and there is no mesoderm? |
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Definition
| mouth formation, anus/vagina formation |
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Term
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Definition
A ventral outgrowth of the hindgut of the early embryo, which expands to form a large sac, filled with urine-like fluid, that fuses with the chorion to make up a major part of the placenta. it is the precusor for an excretory system |
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Term
what is happening as yolk sac is getting smaller and smaller can getting pinched shut?
where forms where it pinches shut? |
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Definition
the placenta is becoming more mature and becomes capable of sustaining the embryo.
a belly button |
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Term
Vitelline Vessels and directions |
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Definition
There is a vitelline artery and a vein. The artery blood to the yolk sac from the embryo. The vein carries blood to the embryo from the yolk sac.
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Term
Umbilical Vessels and directions |
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Definition
These are subdivided into an artery and vein. The artery carries blood from the fetus to the placenta. The vein returns oxygenated blood from the placenta through the umbilical cord to the ductus venosus and thence to the heart.
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Term
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Definition
A part of the embryonic mesoderm. This part forms connective tissue, bone, cartilage, and the circulatory and lymphatic systems develop.
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