Anatomy and Cell Biology 3319 Study Guide - Midterm Guide: Nucleus Accumbens, Schwann Cell, Glossopharyngeal Nerve
22 Mar 2018
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Describe fate of inner cell mass and trophoblast during second week of development. Identify 3 germ layers and describe 2 anatomical structures derived from each layer. Embryo = first 8 weeks; then is considered a fetus. Zygote 4-cell stage morula early blastocyst implanting blastocyst at approx. day 6. Ectopic pregnancy = incorrect location: abdominal pregnancy can be mistaken for appendicitis, majority of times gestation will not go to full term. Zona pellucida is from egg itself; keeps everything intact, thick basement membrane. Zona pellucida degenerates (early blastocyst late blastocyst), allows expansion of blastocyst and further fluid accumulation. Bilaminar embryonic disc: hypoblast lower part; forms yolk sac (not as important for humans as compared to chickens, epiblast upper part; has the primitive streak; establishes polarity (head vs. tail, right vs. left) Formation of trilaminar embryo: cells from either side of primitive streak migrate and converge to streak and go inwards; go below epiblast. Formation of the notochord (slide 21) look over.
