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6 Cards in this Set
- Front
- Back
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Trunk mesoderm of a neurula (meaning going through neurulation)-stage embryo can be subdivided into four regions:
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=Chordamesoderm: duh, because forms notoCHORD. central region of trunk. transient organ whose major functions include inducing the formation of the neural tube and est. the anterior posterior body axis.
=Praxial mesoderm or Somitic: flanks both sides of chordamesoderm. Tissues developing from this region will be located in back of embryo along the spine>form somites which are blocks of mesodermal cells on either side of the neural tube.>somites become many of connective tissues of the back (bone, muscle, cartilage, and dermis) -Intermediate mesoderm: forms urogenital system, consisting of kidneys, gonads, and associated ducts. The outer (cortical) portion of the adrenal gland also derives from this region. =Lateral plate mesoderm: farthest from chordamesoderm, gives rise to the heart, blood vessels, and blood cells of the circulatory system, as well as the ling of the body cavities and to all the mesodermal components of the limbs except muscles. Also forms a series of extraembryonic membranes that are imp. for transporting nutrients to the embryo. |
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Review about Sonih hedgehog protein and the TGF- B family of BMP's
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-dorsal portion neural tube influenced by epidermis=BMP
-ventral portion influenced by notochord=SHH -secondary signaling center within neural tube itself are induced by shh and Bmp respectively -shh makes the floor plate which will then secrete more shh and BMP make roof plates into secreting centers and secrete as well. Causes high conc. at roof and floor respectively with less of each toward the middle. -these factors interact to instruct synthesis of different transcription factors. Will cause different type of neurons to be made> ventral neurons with heavy shh concentration inter with a little less; dorsal neurons with BMP same just not ventral |
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Four subdividsion(before review slide) thought to be specified along the meridiolateral axis by increasing amounts of _____ >hint paracrine factor
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-BMP's
-lateral mesoderm higher levels of BMP4 than midline, thought different BMP conc. may cause differential expression of the forkhead (fox) family of transcription factors |
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So what all is going on while neurulation also happening?
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neural tube is forming, but below also forming mesoderms which are developing into somites and also getting the coelem developing and the primitive gut.
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Lateral plate mesoderm are farthest fom chordamesoderm. split horizontally into layers:
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-dorsal layer>somatic mesoderm which underlies ectoderm and toogether with the ectoderm forms the somatopleure [towards outside]
-ventral layer is the splanchnic (visceral) mesoderm which overlies the endoderm and with endoderm forms splanchnopleure -space between two layers becomes body cavity or coelem> which stretches from future neck region to posterior of the body. later right and left sides of coelems fuse and folds of tissue extend from the somatic mesoderm to divide cavity into separate sections. In mammals, coelem sundivided into pleural, pericardial, peritoneal cavities enveloping thorax, heart and abdomen respectively. |
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Circulatory system is first function system in developing embryo and heart is first functional organ. vertebrate heart arises from what two regions of the ________
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two regions of splanchnic mesoderm (overlies the endoderm)-one on each side of the body-that interact with adjacent tissue to become specified for heart development
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