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Introductory Biology II: Embryology

Deleted user User has deleted their subject information English 56 cards

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  1. 1End result of spermatogenesisfour non-identical sperm cells produced
  2. 2End result of oogenesis1 large ovum produced and 3 non-functional polar bodies
  3. 3Fertilizationoocyte undergoes meiosis, sperm cell fuses with ovum to form a zygote
  4. 4Cleavagelots of RAPID cell divisions in zygote, very little growth or transcription, reduction of cytoplasmic volume, axes form
  5. 5Blastulahollow ball of cells resulting from cleavage
  6. 6Gastrulationmake 3 distinct "germ" layers (endoderm, mesoderm, ectoderm) in Blastula, results in primitive gut formation
  7. 7Gastrula3 layered embryo
  8. 8ectodermforms nervous system and outer layers of skin
  9. 9endodermforms digestive tract. respiratory tract, and digestive organs
  10. 10mesodermforms kidneys, heart, muscles, bones
  11. 11Animal pole vs vegetal poleAnimal pole divides faster; dark brown coloring in Xenopus laevis; later are the ectoderm axis
  12. 12Cell movements during gastrulationa lo of cells rush in from the outside and the rest spread themselves out (epiboly) thinly in an stretched out layer
  13. 13Molecular basis of gastrulationchanges in cell adhesion
  14. 14fate mapstracking cells in time and space; show where each tissues of germ layer originally came from; do NOT inform us about when states of cell determination occur
  15. 15Roux's experimentexperimented by killing one frog blastomere cell at two cell-stage and observing the other's development
    concluded that blastomeres at the earliest stage have a predetermined fate and only a half embryo can form
  16. 16Driesch's experimentseparated sea urchin cells at two-cell stage and observed growth of a small but otherwise normal larvae
    revealed that at two (and four) cell stages, individual blastomeres are totipotent
  17. 17totipotencythe capacity for a cell to give rise to any embryonic cell type
  18. 18Horstadius' tier experimentsseparate cells at 8 cell stage --> get a ciliated blastula and a vegetalized blob
    reveals how cells lose totipotency and become committed to a developmental fate as development proceeds
  19. 19John Gurdon's experimentstake adult frog skin cell and tadpole gut epithelial cell, destroy nuclei, and transfer nucleus into unfertilized eggs --> tadpoles develop
    shows that genetic information is not lost as cells differentiate
  20. 20Regulative Development Modelearly embryos have a capacity for regulation; have developmental plasticity
  21. 21Asymmetric DivisionSister cells can be born differently despite having the same genetic information
  22. 22Symmetric DivisionSister cells with the same genetic information become different as a result of different neighbors acting on them
  23. 23How do cells know which genes to express?the combination of internal information from asymmetrical distribution & external information from cell-cell signaling
  24. 24How animal-vegetal axis is determined (in Xenopus)Determined maternally; egg radially symmetric before fertilization & there is differential localization of maternal mRNAs
  25. 25How dorsal ventral axis is determined (in Xenopus)determined by where the sperm enters --> makes the cortex rotate 30 degrees
  26. 26Inductioncell-cell interactions cause special tissues to develop
  27. 27Spemann's separation experimentdivided two cells with a baby hair, one half could grow own embryo BUT plane of division is crucial
  28. 28The Organizercluster of cells in developing amphibian embryo that induce development of central nervous system; crucial discovery to concept of induction
  29. 29dorsal lip of the blastoporecells that are COMMITTED to invaginate into the blastula, "the Spemann organizer," formed by the gray crescent region of an egg
  30. 30Results of dorsal lip transplantcontinued to be committed to its "fate" --> initiated a second gastrulation in surrounding tissue and two embryos/axes form via induction
  31. 31B-cateninprotein that can induce changes in cell fates based on where it accumulates; can form new dorsal regions when injected
  32. 32Specificationwhen the mesoderm is under the ectoderm, tissue is specified to become the nervous system BUT if moved it could become something else
    NOT irreversible!
  33. 33Determinationwhen cells will produce the determined cell types and will not be altered by inducers to become completely different
    IRREVERSIBLE
  34. 34Involuting Marginal Zone cellson the dorsal lip of the blastopore in developing Xenopus eggs, move to the interior via invagination and become the mesoderm
  35. 35NeurulaWhat the embryo is called after gastrulation leads to the formation of the neural fold --> notochord
  36. 36What's in a human sperm cell?Haploid nucleus, centriole (forms spindles during division), mitochondria, acrosome enzymes (to digest egg coat)
  37. 37What's in a human egg cell?Egg cytoplasm: nutritive proteins, ribosomes & tRNA, **mRNAs**, morphogenetic factors, protective chemicals, egg cortex (cortical granules)
    Vitelline membrane to attract and activate sperm + regulate ion flow
  38. 38Egg-sperm recognitionExocytosis of sperm's acrosomal vesicle, bindin coats sperm actin filaments and binds sperm to vitelline envelope, sperm passes through and membranes fuse
  39. 39Fast block to polyspermyDepolarization of egg electric potential due to influx of Na+ means no more sperm can fuse
  40. 40Slow block to polyspermycortical granules cleave links between vitelline membrane and plasma membrane, stimulated by increase in intracellular Ca2+ from sperm fusion
  41. 41Follicle Stimulating Hormone (FSH)produced by pituitary gland, controls production of oocytes in women and sperm in men; stimulates production of estrogen in women
  42. 42Corpus luteuminvolved in production of progesterone, left behind after egg leaves in ovulation, maintains uterine lining (endometrium)
  43. 43Luteinizing hormonehormone that triggers ovulation and development of corpus luteum
  44. 44where does fertilization (as well as the first cleavage) occur?in the fallopian tube/OVIDUCT
  45. 45first ball of cells after cleavage in humansthe morula
  46. 46human chorionic gonadotrophin (hCG)hormone secreted by specialized cells that maintains the corpus luteum after implantation
  47. 47Implantationhuman blastula is implanted into endometrium, trophoblast outer layer forms placenta so direct nutrient exchange can occur
  48. 48chorionic gonadotropinhormone secreted by trophoblast and chorion that maintains corpus luteum after implantation
  49. 49The Four Extra-embryonic Membranes1) Chorion
    2) Amnion
    3) Yolk Sac
    4) Allantois
  50. 50Choriontrophoblast, surrounds everything
  51. 51Amnioncushions embryo and prevents desiccation; is fluid filled
  52. 52Yolk sacforms blood cells that migrate into the embryo, doesn't actually contain yolk
  53. 53Allantoisdevelops from archenteron (gut) outgrowth, becomes a part of the umbilical cord
  54. 54First Trimesterthree germ layers --> limb buds --> developed enough to be called an embryo (non-self) --> limb elongation --> organs are in place --> hCG levels drop and CL begins to disentegrate
  55. 55Second Trimesterprogesterone production --> general growth --> bone development --> heart beating --> vernix (skin) covering
  56. 56Third trimesterweight increase --> eyelids split --> lungs mature --> hearing develops --> uterine cavity full

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Description
Embryology
Created by
Deleted user · Apr 2020
Updated
Apr 7, 2020
Views
13
History
  • Created by Candice Young · Aug 8, 2017
  • Copied by Gabriel Kofi · Apr 7, 2020
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