Pregnancy & Development

  1. What are the stages of pregnancy?
    • Fertilization
    • Embryonic Development
    • Fetal Development
    • Childbirth
  2. What happens during fertilization?
    • Egg is viable 12 - 24 hours
    • Sperm is viable 12 - 48 hours
    • Sperm make their way to uterine tube, oocyte pulls in head of sperm, not allowing a second sperm to enter, then undergoes division.
    • Fertilization happens when genetic materials form a zygote
  3. What is a zygote?
    First cell of a new individual, resulting from fusion of genetic material between oocyte and sperm, that rapidly undergoes mitotic division while in the uterine tube moving toward the uterus
  4. What is an embryo?
    • Developmental stage from cleavage - 9th week
    • Embryo enters uterus at 16 cell state
    • Temporarily floats free in the uterus
    • Nourished by uterine secretions
  5. What is the blastocyst?
    Ball-like circle of around 100 cells consisting of a trophoblast - large fluid filled sphere, and an inner cell mass, that secretes hCG
  6. What are the 3 germ layers of the blastocyst?
    • Ectoderm - Outside layer, becomes nervous system and epidermis
    • Mesoderm - Middle layer, becomes mucosae and glands
    • Endoderm - Inside layer, becomes everything else
  7. What does the placenta do?
    • Delivers nutrients and oxygen
    • Forms barrier between mother and embryo
    • Removes waste from embryonic blood
    • Produces hormones
  8. What is the fetus?
    • Baby at beginning of 9th week
    • All organ systems are formed
    • Tremendous growth and change in appearance
  9. What are the physiological changes of pregnancy on the mother?
    • Body water rises
    • Blood volume increases 25 - 40 percent
    • Blood pressure and pulse increase
    • Varicose veins common
  10. What happens during childbirth (partition)?
    • Labor - estrogen rises, contractions, Oxytocin released, prostaglandins
    • Dilation - Cervix dilates, contractions increase, amnion ruptures
    • Expulsion - Infant passes through cervix and into vagina
    • Placental - Delivery of placenta
  11. How is gender determined?
    • At fertilization:
    • XX Female
    • XY Male
    • Gonads form in 8th week
Card Set
Pregnancy & Development
Pregnancy & Development