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Conception and prenatal development Chapter 12

  1. Gametogenesis produces ova and sperm that have half the full number of chomosomes or 23 unpaired chromosomes when and ovum and a sperm unite at conception, the number is restored to 46 paired chromosomes as in other body cells.
  2. No new ova are formed after 30 weeks of prenatal gestation
  3. One primary oocyte results in one mature ovum that contains 23 unpaired chromosoms (22 autosomes and an X chormosome)
  4. A male can continuously produce new sperm from puberty through the rest of his life, although this production gradually declines with age.
  5. One primary spermatocyte results in production of four mature sperm.  Two of the mature perm have 22 autosomes and an X chromosome.  two have 22 autosomes and a Y sex chromosome
  6. THe male determines teh babys sex because sperm carry either an X or a Y sex chromosome.  The female contributes only an X chroomosome to the baby.
  7. THe basic structure of all organ systems is established during the first 8 weeks of pregnancy.  Teratogens during this period can cause major structural and functional damage to the developing organs.
  8. The fetal period is one of growth and refinement of established organ systems.
  9. The placenta is an embryonic or fetal organ with metabolic respiratory and endocrine functions.
  10. Transfer of substances between mother and her developing baby occurs by four mechanisms: simple diffusion facilitated diffusion active transport and pinocytosis.
  11. Most substances in the maternal blood can be transferred to the fetus.
  12. The fetal membranes contain the amniotic fluid which cushions the fetus allows normal prenatal development and maintains stable temperature
  13. Two umbilical arteries carry deoxygenated blood and waste product to the placenta for transfer to the mothers blood one umbilical vein carries oxygenated and nutrient rich blood to the fetus.  Coiling of the vessels and enclosure in WHartons Jelly reduce compression and torsion of the umbilical vessels.
  14. Three fetal circulatory shunts partially bypass the liver and lungs the ductus venosus the foramen ovale and the ductus arteriosus.  These structures close functionally after birth but are not closed permanently until several weeks or months later
  15. Multifetal pregnancy may be monozygotic or dizygotic. twins are the most common form of multifetal pregnancy
  16. Dizygotic twins are more likely to occur in certain families and racial groups, in older mothers, and in women who undergo infertility therapy.
  17. Non-sex hormone
    Autosome
  18. Results of a fetilized ovum
    Conceptus
  19. Cells that remain after ovum formation and secrete estrogen and progesteron
    Corpus luteum
  20. Developing baby from weeks 3 through 8
    Embryo
  21. Reproductive cell
    Gamete
  22. Cell division in body cells
    mitosis
  23. Formation of female gametes
    oogenesis
  24. Release of the mature ovum from the ovary
    Ovulation
  25. Structure that provides nourishment for developing baby
    Placenta
  26. Ordinary body cell
    Somatic cell
  27. What are the two major occurrences immediately after fertilization
    the zona pellucida prevents the other sperm from entering and the ovum completes its second meiotic division.
  28. List three reasons the fundus is the best area for implantation
    Good blood supply thick uterine lining muscle to limit post birth blood loss
  29. When during prenatal development does this event occur? Closure of the neural tube
    4 weeks
  30. When during prenatal development does this event occur? Heart contains four chambers
    8 weeks
  31. When during prenatal development does this event occur? all abdominal organs are within the abdominal cavity
    10 weeks
  32. When during prenatal development does this event occur? External ear development begins
    6 weeks
  33. When during prenatal development does this event occur? Fetal sex apparent by external genitalia
    12 weeks
  34. When during prenatal development does this event occur? fetal movements felt by mother
    16-24 weeks
  35. When during prenatal development does this event occur? surfactant production begins
    24 weeks
  36. Describe the fetal structure or substance and state their purpose?  Vernix caseosa
    creamy skin covering to lubricate and protect fetal skin from amniotic fluid
  37. Describe the fetal structure or substance and state their purpose? Lanugo
    fine downy hair that helps vernix adhere to the skin
  38. Describe the fetal structure or substance and state their purpose? Brown fat
    heat producing fat found in back of the neck behind sternum and around kidneys
  39. Describe the fetal structure or substance and state their purpose? Surfactant
    Surface active lipid substance that helps alveoli remain slightly open between breaths to ease the work of breathin
  40. Explain how the following mechanisms allows the fetus to thrive in the relativly low oxygen environment of the uterus?Fetal H/H
    A high fetal H/H give the fetus more oxygen carrying capacity fetal hemoglobin can carry 20% to 50% more oxygen than adult hemoglobin
  41. Explain how the following mechanisms allows the fetus to thrive in the relativly low oxygen environment of the uterus? Relative fetal and maternal blood carbon dioxide levels
    Fetal carbon dioxide quickly diffuses into the mothers blood causing her blood to become more acidic and fetal blood to become more alkaline this allows fetal blood to combine with oxygen more readily
  42. Describe how passage of maternal immunoglobulin G (IgG) antibodies can be either benifical or harmful to the fetus? beneficial
    Provides the newbore with temporary passive immunity to disease to which the mother is immune
  43. Describe how passage of maternal immunoglobulin G (IgG) antibodies can be either benifical or harmful to the fetus? Harmful
    Maternal blood type antibodies may cross the placenta and destroy incompatible fetal erythrocytes
  44. Explain the function of this placental hormone? Human choionic gonadotropin (hCG)
    Causes persistence of the corpus luteum to maintain estrogen and progesterone secretion during early pregnacy and causes fetal testes to secrete testoterone to stimulate development of normal male reproductive structures
  45. Explain the function of this placental hormone? Human placental lactogen (hPL)
    Promotes normal growth and nutrition of the fetus stimulates maternal breast development and makes more glucose available to the fetus by reducing maternal insulin sensitivity and glucose utilization
  46. Explain the function of this placental hormone? Estrogen
    causes uterine and breast enlargment growth of the breasts ductal system and enlargement of fetal external genitalia
  47. Explain the function of this placental hormone? Progesterone
    Change endometrium into decidua to nourish conceptus before placenta is established reduces uterine contractions and stimulates breast growth and development of the breast alveoli and ductal system
  48. State the three functions of amniotic fluid?
    Cushions fetus from impacts

    provides stable temperature

    Promotes normal fetal growth and development (Promotes symmetrical development preventing membrane adherence and allows fetal movement)
  49. Explain the umbilical cord structure and functions? Umbilical vein
    Carries oxygenated blood and nutrients from the placenta to the fetus
  50. Explain the umbilical cord structure and functions? Umbilical arteries (two)
    Carries deoxygenated blood and waste products from the fetus to the placenta
  51. Explain the umbilical cord structure and functions? Whartons jelly
    Protects the cord vessels from stretching or pressure that would interrupt flow
  52. An important purpose of seminal fluid is to?
    protect sperm from the acidic vaginal environment
  53. Fertilization is complete when?
    Fusion of the sperm and ovum nuclei occurs
  54. The embryois fully implanted in the uterus on which day after conception?
    10
  55. Which fetal circulatory structure carries blood with the highest oxygen concentration
    umbilical vein
Author
jessem30
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214220
Card Set
Conception and prenatal development Chapter 12
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Conception and prenatal development Chapter 12 Spc Nursing
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