1. Conception
    Union of a single egg and sperm marks the beginning of antepartal period
  2. conception usually occurs when?
    within 12-24 hrs after ovulation in the outer third (ampulla) of the fallopian tube
  3. Diploid number of chromosomes is reestablished with what?
  4. egg and sperm united to form the single cell known as the
  5. Implantation usally occurs when?
    withing 7 days of conception, or about day 21 of a 28 day menstrual cycle
  6. Implantation

    moves the first layer of the edometrium slightly and embeds in the endometrium usually in the top (fundal) portion of the uterus at about day 6-10
  7. Implantaion occurs when entire blastocyst is cover by?

  8. Implantation

    Chorionic villi extend from the blastocysts into the endometrium which is thick and vascular from progesterone) to?
    gain nutrients from mother and to get rid of CO2 and waste products.
  9. After implantation the endometrium is renamed?
  10. During 10-14 days after conception the blastocyst differentiates into?
    three primary germ layers: ectoderm, mesoderm, and endoderm.

    formed at the same time as the embyonic membranes
  11. all tissues and organ systems will develop from?
    the three primary germ laters
  12. Embryonic stage last how long?
    from day 15 until 8 weeks after conception or until the embryo measures 3cm (crown-rump)
  13. yolk sac
    forms primitive red bloods cells during the first 6 wks of embryo development until the liver takes over the process.
  14. provides oxygen and nutrients while uteroplacental cirulation is established
    yolk sac
  15. By the 3rd wk heart begins to beat and circulate blood through?
    embryo, stalk, chorion, and yolk sac
  16. yolk sac is eventually incorporated into the
    umbilical cord
  17. Two __________ begin to develop at time of implantation
    fetal membranes
  18. function of fetal membrane
    support embryo as it grows and develops inside uterus
  19. chorion
    outer cell membrane develops from the trophoblast and contains chorionic villa on its surface (thick)
  20. fetus may survive outside the uterus when?
    currently at 27 wks after conception. possible at 20 wks post conception or 22 wks since LMP (500g fetal weight)
  21. tubular heart begins to beat and CV system links embryo, stalk, chorion and yolk sac when?
    3 wks
  22. 4 chamber heart is seen when?
    4th week
  23. organ systems and external structures visible by
    wk 9
  24. lungs do not function for gas exchange, therefore
    we need alternative cirulatroy pathway
  25. fetal heart is controled by
    its own pacemaker
  26. Fetal Heart

    SA node sets the rate and supplied by
    vagus nerve
  27. Fetal Heart

    AV node bridges the ________ and ______ and is supplied by ________
    atrium, ventricle, vagus nerve
  28. stress on fetus causes sympathetic nervous system to release _____________, which _______the fetal heart rate.
    norepinepherine, increases
  29. how does the fetal heart counteract in increase in rate and blood pressure?
    baroreceptors which respond to stretch and vagus nerves cause the heart to slow
  30. Central Nervous System also controls
    fetal heart rate
  31. increase activity of fetus exhibits?
    increase in beat to beat variablity of fetal heart baseline.
  32. sleep patterns demonstrate?
    decrease in beat to beat variablity of fetal heart baseline
  33. in sever hypoxia, increase levels of epinepherine and norepinepherine act to?
    make the heart faster and stronger
  34. how commone is twins
    1 in 80 pregnancies
  35. how commone is triplets
    1 in 8000 pregnancies naturally
  36. fraternal-dizygotic (twins)
    two separate ova fertilized by two separate sperm. two placentas, two chorions, and two amnions, however placentas sometimes fuse and look like 1. no more alike than if they were born separately.
  37. identica - monozygotic (twin)
    develop from single ovum. same sex and genotype(appearance) common placenta
  38. how long does pregnancy last?

    calculated how?
    10 lunar months; or 40 wks; or 280 days

    from the beginning of the last menstrual period to the time of birth
  39. fertilization age or post conception age of the fetus is calculated how?

    more accurate why?
    about 2 wks less or 266 days (38 wks)

    measures fertilization of the ovum, or conception
  40. preembryonic stage

    characterized by?
    1st 14 days of development after ovum is fertilized

    rapid cell multiplication and differentiation and establishment of embryonic membranes and primary germ layers
  41. embryonic stage

    period when tissue?

    embryo is most vulnerable to ?
    begins at day 15 (3rd week after conception or fertilization) and continues until 8 wkds or until embryo reaches crown0rump length of 3 cm

    differentiates into essential organs

    teratogens up until about the 12th wk
  42. weeks 4-6
    • at 28 days arm and leg buds become visible; tail bud present until now
    • takes human form
  43. at 4 wks tubular heart is beating a regular rhythm and?
    pushing primitive blood cells throught the main vessels
  44. 5th week formations
    eyes and nasal pits form

    embryo looks c shaped

    brain differentiated into 5 areas and 10 pairs of cranial nerves recognizable
  45. at 6wks liver is doing?
    making RBC's and fetal circulation establihed
  46. 7th week formations
    eyelids form, embryo rounded and nearly erect. palate nearing completions; tongue developing

    GI and GU tracts now 2 separate structures

    umbilical herniation present
  47. 8th wk formations
    3cm and clearly looks like a human being; eyelids fuse; auricles of ears assume shape; external genitals appear; anus formed; cirulatory system through umbilical cord established; long bones begin forming
  48. Fetal Stage
    begins at end of 8th wk

    every organ system that will be found in full term newborn is present

    remainder of gestation is oto refine the organ structures
  49. at week 9 the head is how loarge?
    1/2 of fetus's entire size
  50. 12 wk formations
    • fetus is 3.2 inches and wighs 1.6 oz
    • face is well formed
    • eyelids close and will not reopen until 28 weeks
    • sucking relfex observed
    • tooth buds appear
    • curls fingers
    • legs shorter than arms
    • urogenital tracts complete
    • kidneys make urine
    • spontaneous fetal movement occurs
    • fetal heart tones hear by doppler at 11 wks
    • FHR is approximately 120-160BPM
  51. 13-20 wks
    • period of rapid growth
    • at 13 wks is 3.6 inches and 2oz
    • lanugo develops on head
    • skin transparent - can see blood vessels
    • active movements are present as fetus stretches and exercises
    • sucking motions, swallows amniotic fluid, and produces meconium in GI tract
    • primitive lungs, sweat glands are developing
    • liver and pancreas begin secretions
    • skeletal ossification is identifiable
  52. weeks 20-24
    • double in C-R lenght and measures 8 inches, weighs 16-16oz
    • lanugo over entire body; subcutaneous brown fat has rich blood supply makes skin less transparent
    • nipples appear, head is covered with wooly hair
    • muscles are developed
    • fetal movement (quickening) felt by mother
    • aveoli in lungs beginning to form
  53. 24 wk formations
    • C-R lenght is 11.2 inches and weighs 1lb 10oz
    • hair is growning long
    • reflex hand grip
    • little subcutaneous fat
    • skin ridges on palms and soles
    • skin is covered by fatty substance secreted by sebaceous glands called Vernix Caseosa
    • alveoli in lungs beginning to form
  54. weeks 25-28
    • marks 6 calendar months
    • fetal skin, wrinkled and covered with vernix
    • brain rapidly debeloping
    • nervous system complete
    • nails on fingers and toes
    • eyelids open and close per nueral control
    • lungs, although immatrue provide some gas exchange
  55. week 28
    • 14-15 inches long and 2lbs 20oz02lbs 12oz
    • can survive outside womb with intensive care
  56. weeks 29-32
    • pupillary light reflex +
    • gaining weight period
    • lungs not fully matrue but CNS regulates breathing movements and partially controls body temperature
    • testicles located in scrotal sac in some fetuses
  57. 30 wks
    weighs 4 lbs 6 oz and is 15-17 inches long
  58. weeks 32-38
    • gets fat stores and less wrinkled with more subcutaneous fat deposits present
    • lanuga disappears slowly
    • nails reach edge of fingertips
  59. 35 wks
    firm grasp and spontaneous orientation to light
  60. 36 wks
    weights 51/2 to 6 lbs and is 16-19 inches long

    good chance of surving by may require some special care

    lungs not fully matured yet
  61. weeks 38-40
    considered full term at 38 wks after conception; 40 wks per calendar method

    lenght should be between 18-21 inches long with males longer than females

    weight @term is 6lbs 10 oz to 7lbs15oz

    • skin polished look
    • lanugo on shoulder upper arms only
    • vernix caseosa present in creases and folds of skin
    • chest smller than head
    • assumes positionor lie in pelvis
    • after 5 months already has established feeding pattersk, leeping patterns, activity patterns
  62. factors influencing embryonic and fetal development
    • quality of sperm or ovum from which zygote was formed
    • genetic code established at fertizlization
    • adequacy of itrauterine environment
    • after differentiation is complete the fetal membrans are fromed and an injuious agent has the greates effect on those cells undergoing the most rapid period of growth
    • maternal nutrition can affect brain development and disease
    • primary nutries for brain development are amino acids, glucose and fatty acids
Card Set
Test 1