User talk:Z3372824: Difference between revisions
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• HUGEEE variability in number of NGF’S (oocytes) lose it by apoptosis (atresia) | • HUGEEE variability in number of NGF’S (oocytes) lose it by apoptosis (atresia) | ||
• Ovary lies within peritoneal cavity. Oocyte increases in volume, 4 hormones released. | • Ovary lies within peritoneal cavity. Oocyte increases in volume, 4 hormones released. | ||
• hcG synthesised by syn/blsat. Local secretion. Taken up by maternal blood through lacunae. Preserves the corpus luteum- makes progesterone which maintains uterus in secretory phase. | |||
• Placenta takes over (after placentation, get the endocrine role of placenta function) e.g. estrogen and progesterone. | |||
• Extravillous syto.blast. mixed in with maternal stroma and surround ? | |||
• Epiblast and hypoblast = week 2. Presence of endometrial to dissidual cells = indicates pregnancy. | |||
• Endometrial glands secrete onto surface, empty into lacunae (has maternal blood and endometrial glands) | |||
• Chorionic cavity= largest space. Forms placenta (chorion frondosum- week 3), few villi. Other side has a lot of villus(mothers vessels) | |||
• Conceptus: embryo and extraembryonic apparatus. | |||
• Decidua b. maternal contribution. | |||
• Decidualisation occurs over entire uterus. | |||
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Revision as of 13:05, 28 August 2015
• Some cells live just a day, liver 1 month etc. variable time • 2 copies in genome (us) crossing over occurs in gametes. Following s phase: 4 copies of every chrom. Duplication to get 2 daughter cells.
• G1- GROWING IN VOLUME. Most variable time in life. Check point: division of cell okay? Screening: bad: won’t copy genome, stops uncontrolled cell replication • G0: leaves cell cycle that cant divide again. E.g. Satellite cells (transiently there) • S Phase: (before mitosis) duplication of genome. Check point 2: copy of chromosome okay? No= stops cell dividing. If checkpoint goes bad: cancer e.g. p53. • G2: gets cell ready to divide (mitosis entry: so stock up on ATP) In mitosis no gene expression! Cant make new energy. (short prd of time) • 5 stages of mitosis: prophase, prometa, meta, ana, tela (defined by nucleus underlying mitosis) 2. Disassemble cytoskeleton. Microtubules form spindle only during mitosis: transport vesicles, nucleus) NO ROADWAY: so no exocytosis, endosytosis • Cytokinesis: division of cytoplasm. Overlaps with telophase. Microfilament (actin filaments) acts as belt, cuts into 2. • Meiosis diff to Mitosis : does it twice: but no duplication again: so get haploid. Crossing over. No duplication. Recombination occurs. Only 1 copy of every chromosome. Only in germ cells. Recomb : prophase 1. Indep assortment of chromosomes in meiosis 1. Progeny diff not identical.
• Female gametogenesis occurs in embryo. Oogenesis. Normally puberty: 12-13. All arrested at meiosis 1. Only complete meiosis 1 once oocyte released. (grafted follicle only, other follicles don’t complete it). Ovulated oocyte doesn’t complete meiosis 2 unless its fertilised. When it does, get a second polar body. Possible: 1st polar body also undergoes meiosis 2 then get 3 polar body. No point. • Meiosis 1 = major cause of Down’s. 1 chromosome gets left behind on spindle apparatus = 3 chrom 21’s. Instance increase with age. Aneuploidy= abnormal number of chrom. Meiosis safest when it occurs quickest, age increase, resources decrease. More env. exposure. • Male: diploid spermatogonia in testes. Around periphery of seminiferous tubule. Undergo mitosis before meiosis ( to replace itself coz it’s a stem cell). Setoli cells: support to spermatozoa. Its junctions form blood-testes barrier. • Primary spermatocyte : meiosis 1. Secondary spermatocute: meisos 2 ( cant see it coz it does it so quickly) Spermatid: round, haploid cell that’s completed meiosis, but hasn’t completed everything yet in development? Cytokinesis not completed! All progeny joing by cyto bridges? UNLIKE FEMALE 2 with x chromosomes, 2 with y. • Oocyte takes years, male takes 44 days? • Cortex thicker in infant (only primordial follicles), than older. Get germinal epithelium then cortex then medulla? Stromal cells (tiny dots?) • Medulla: large maternal blood vessels. Not many primordial oocyes here. • HUGEEE variability in number of NGF’S (oocytes) lose it by apoptosis (atresia) • Ovary lies within peritoneal cavity. Oocyte increases in volume, 4 hormones released.
• hcG synthesised by syn/blsat. Local secretion. Taken up by maternal blood through lacunae. Preserves the corpus luteum- makes progesterone which maintains uterus in secretory phase. • Placenta takes over (after placentation, get the endocrine role of placenta function) e.g. estrogen and progesterone. • Extravillous syto.blast. mixed in with maternal stroma and surround ? • Epiblast and hypoblast = week 2. Presence of endometrial to dissidual cells = indicates pregnancy. • Endometrial glands secrete onto surface, empty into lacunae (has maternal blood and endometrial glands) • Chorionic cavity= largest space. Forms placenta (chorion frondosum- week 3), few villi. Other side has a lot of villus(mothers vessels) • Conceptus: embryo and extraembryonic apparatus. • Decidua b. maternal contribution. • Decidualisation occurs over entire uterus.
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First Read the help page Images and Copyright Tutorial.
Students cannot delete images once uploaded. You will need to email me with the full image name and request deletion, that I am happy to do with no penalty if done before I assess. Non-Table version of this page
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