Chapter 2 - Prenatal D'vnt and the Newborn Period Flashcards
What do all humans originate from the union of?
2 gametes (1 egg from mom and 1 sperm from dad)
What are gametes formed through?
How much DNA do they have?
- meiosis
- 23 chromosomes each which creates 23 pairs once united during conception
Describe the process of reproduction.
- egg launched from the ovary into fallopian tube
- egg is released and 500 mill sperm enter vagina
What is a fertilized egg called?
a zygote
Why is there a high failure rate of sperm during reproduction?
- genetic defects
- survival of the fittest (a long journey to the egg)
What are the 3 periods of the prenatal phase, how long is each?
- Germinal period (conception - 2nd week)
- Embryonic period (3rd - 8th week)
- Fetal period (9th week - 39th week/ birth)
Which prenatal period is there the most rapid development during?
embryonic period
What are the 4 developmental processes in the germinal period?
- cell division
- cell migration
- cell differentiation
- cell death (apoptosis)
When does hormonal influence start in the prenatal period?
- week 8 (germinal period)
- they’re important for cell differentiation
What is the difference between identical and fraternal twins in early cell development?
Identical twins:
- cells divide with same genetic material
Fraternal twins:
- two eggs are fertilized
What are some important support systems in prenatal development? What do these structures do?
- amniotic sac: protects fetus
- placenta: transports nutrients and expells waste
- semipermeable membrane
- umbilical cord: blood vessels connecting fetus to placenta/mom
Describe some initial fetal movement behaviors.
- spontaneous movements (5 weeks after conceptions)
- initial jerkiness becomes more integrated
- by 12 weeks, most movements present at birth have appeared
What are some important forms of movement for a fetus?
- Swallowing: helps palate and digestion d’vt
- breathing
- burping
- yawning
- hiccups
Describe a fetus’s visual and tactile experience.
- minimal visual experience
- more tactile experience
Describe a fetus’s taste experience
- flavors in amniotic fluid
- taste sensitivity
- fetal preferences (prefer sweet fluid)
Describe a fetus’s smell experience.
- amniotic fluid smells may vary depending on what mother ingests
Describe a fetus’s hearing experience.
- external sounds are audible to fetus
- mostly hear mother’s bodily sounds
- respond to sounds by 6 months
What is fetal habituation? What does it measure?
- the decrease response to repeated or continued stimulation
- measures learning
What’s another term for miscarriage?
spontaneous abortion
What is the leading cause of miscarriages?
genetic deficits
What is a teratogen?
an environmental agent that has the potential to cause harm during prenatal development
What is a crucial factor in the severity of the effects of exposure to teratogens?
the timing of exposure in the prenatal development timeline
What is the most sensitive period to be exposed to teratogens? Why?
the embryonic period
- the development of many important structures happens during this time
