Muscle Physiology 462

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Muscle Physiology 462
2012-01-12 18:09:22
muscle physiology

muscle physiology
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  1. What are the characteristics in Carnegie stage 4?


    • -Anchoring of the blastocyst on the endometrium and interaction between the
    • embryo and maternal tissue.

    -Implantation of the blastocyst in the mucosa of the uterus
  2. What are the characterisics of Carnegie stage 1?
    Fertilized oocyte

    Polar bodies

    Male and female pronucleus

    Formation of the zygote
  3. What are the characteristics of Carnegie stage 5a?
    • Development of the
    • bilaminar germ disk

    • Genesis of the amniotic cavity and the primary yolk sac (= primary umbilical
    • vesicle)

    Invasion of the trophoblasts into the uterine mucosa

    Solid trophoblast
  4. What are the characteristics of Carnegie stage 2?
    • Separation of the
    • blastomeres

    Formation of the blastomeres (totipotent to ca. the 12-cell stage)

    Morula stage

    Compaction (8 to 16 cells)

    The polarization of the blastomeres becomes slowly visible.
  5. What are the characteristics of Carnegie stage 5b?
    • Formation of the
    • trophoblast lacunae and complete penetration of the embryo into the endometrium

    Lacunar trophoblast

    Definitive amniotic cavity

    Primary umbilical vesicle (= primary yolk sac)
  6. What are the characteristics of Carnegie stage 3?
    Free blastocyst

    Hatching of the blastocyst through disintegration of the zona pellucida

    Epiblast and hypoblast are formed and thereby the didermic embryonic disk.
  7. What are the characteristics of Carnegie stage 5c?
    • Erosion of the maternal
    • vessels: maternal blood in the lacunae of the throphoblast

    The prechordal plate is formed (see stage 6)

    Extraembryonic mesoblast

    • Transformation of the primary into the secundary yolk sac (= secundary
    • umbilical vesicle)
  8. What are the characteristics of Carnegie stage 7?
    Mesoblast immigration

    Chordal process

    Neural plate

    Genesis of the blood vessel system and formation of blood
  9. What are the characteristics of Carnegie stage 6?
    • Primitive streak, Primitive
    • node Primitive groove

    Secundary umbilical vesicle

    Allantoic diverticulum

    Cloacal membrane

    Primordial vessels in the embryonic body stalk

    Primordial germ cells

    Body stalk
  10. What are the dates for each:
    Stage 1
    Stage 2
    Stage 3
    Stage 4
    Stage 5a
    Stage 5b
    Stage 5c
    Stage 6
    Stage 7
    • Stage 1=Day 1
    • Stage 2=Day 2-3
    • Stage 3=Day 4-5
    • Stage 4=Day 6
    • Stage 5a=Day 7-8
    • Stage 5b=Day 9
    • Stage 5c=Day 11-13
    • Stage 6=Day 17
    • Stage 7=Day 19
  11. What is transcription?
    The process that turns DNA into RNA
  12. What is translation?
    The process that turns RNA into proteins.
  13. What are the steps of transcription?
    • 50 different protein transcription factors bind to promoter sites, and an RNA polymerase (enzyme), binds to the transcription factors. These open the DNA double helix.
    • TheRNA polymerase "reads" one strand of DNA moving in from 3 5.
    • The nucleosomes in front of the advancing RNA polymerase (RNAP II) are removed and replaced after the DNA has been transcribed and RNAP II has
    • moved on.
    • Asthe RNA polymerase travels along the DNA strand, it assembles ribonucleotides (supplied as triphosphates,e.g., ATP)into a strand of RNA.
    • Each ribonucleotide is inserted into the growing RNA strand following the rules of base pairing
    • Synthesis of the RNA proceeds in the 5 3 direction.
    • As each nucleoside triphosphate is brought
    • in to add to the 3 end of the growing strand, the two terminal phosphates are removed.
    • When transcription is complete, the transcript is released from the polymerase and, shortly thereafter, the polymerase is released from the DNA.
  14. What are the rules of base pairing in RNA?
    • For each C on the DNA strand, a G is
    • inserted in the RNA; for each G, a C; and for each T, an A. However, each A on
    • the DNA guides the insertion of the pyrimidine
    • uracil (U, from uridine triphosphate, UTP). There is no T in RNA.
  15. What is the fate of messenger RNA (mRNA)?
    It is translated into a polypeptide.
  16. What is the fate of ribosomal RNA (rRNA)?
    • It is used
    • in the building of ribosomes: machinery for synthesizing proteins by
    • translating mRNA
  17. What is the role of transfer RNA (tRNA)?
    • RNA
    • molecules that carry amino acids to the growing polypeptide.
  18. What is messenger RNA (mRNA)?
    • It encodes polypeptides. Most cells produce small amounts of thousands of different mRNA
    • molecules, each to be translated into a peptide needed by the cell.
  19. Name 4 types of ribosomal RNA:
    • 18S
    • 28S
    • 5.8S
    • 5S
  20. The small subunit of the ribosome is made up of?
    30 different protein molecules + 18S rRNA
  21. What makes up the large subunit of a ribosome?
    45 different proteins + 28S + 5.8S + 5S rRNA
  22. Which rRNA molecules
    are produced by the processing of a single primary transcript from a cluster of
    identical copies of a single gene?
    • 28S,
    • 18S, and 5.8S
  23. Which rRNA molecules
    are produced from a different cluster of identical genes?
  24. Identify
    the key regulators of embryonic myogenesis.
    • MyoD, Myf5, Myogenin, and MRF4

  25. Describe the
    PAX genes and the MRFs (include Mef-2) involved in embryonic muscle generation.