Ch2 Powerpoint slides Flashcards
3 stages of Prenatal development
Germinal, Embryonic, Fetal
Zygote is?
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum. (earliest development)
Germinal stage lasts?
2 weeks from conception
Germinal stage major achievements?
- Rapid cell division (formation of blastocyst)
- Attachment to uterine wall (formation of amnion, and development of placenta)
How many ovum do women have in lifetime
400k
Ovum to sperm ratio
2500/1
Sperm swim how fast
1in per hour, hundreds of millions for each ejaculation
Female vs male sperm
Male faster
Female survive better
Kleinfelters syndrome is?
(XXY) male, after puberty = boobs, less hair, small balls
Turners syndrome is?
(X0) female, Smaller statute, delayed puberty
Monozygotic twins?
Twins who are genetically identical, single egg and sperm
Dizygotic twins?
Twins who are not genetically identical, two eggs and two sperm
Hyperovulate?
2+ eggs per month
When does first cell division occur?
~30hours after conception
When is 2nd cell division?
Day 2, four cells, becomes more rapid over time
When does the germinal period end?
Implantation in uterine wall
Germinal stage, start and end?
Conception- attachment to uterine wall
Embryonic stage lasts from?
2nd to 8th week
Embryonic stage, start and end?
attachment to uterine wall-formation of bone cells
Embryonic stage major achievements?
-growth from 1/4in to 1in
-major organs formed
-movement
Skeletal is last to grow
Cell differentiation?
Process by which a less specialized cell becomes a more specialized cell type. … Differentiation occurs many times during the development of a multicellular organism. The organism changes from a single zygote to a complex system of tissues and cell types.
Cell migration?
Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations.
Embryo composed how many layers of cells. (Name?)
3
Endoderm, mesoderm, ectoderm
Endoderm?
Inner layer. Develop into digestive and respiratory systems, liver and pancreas.
Mesoderm?
Middle layer. Become bones/muscles
circulatory , excretory , and reproductive system
Ectoderm?
Outermost layer of cells. Becomes nervous system, brain, sensory receptors (Ears, nose, eyes) and skin parts
If neural tube (head) doesn’t close, it can lead to?
Anencephaly- brain does not develop properly
Spina Bifida- unable to move properly (still live)
Heart starts beating when?
At 18 days
At 4 weeks what grows?
eye and arm bud
Cephalocaudal development
Development from head down
Proximodistal development
from the center outwards
What happens at 5-6th week
fingers grow, human, spinal cord, legs
Eye opens and closes when?
open at 6.5 weeks, close at 9 weeks. open again at 7months
When do fingernails grow?
17 weeks
Fingerprints grow when?
at 8-9 weeks
Embryonic period ends when?
when bones begin to develop
When can fetus survive outsides the womb?
At 22-24 weeks
Fetal stage is how long?
30 weeks
Fetal stage start and end?
Bone growth-birth
Fetal stage major achievements?
- Grows from 1in to 20 in
- movement felt by mother
- sex known at 12 weeks
- hearing at 5 months
- sensitive to light
Yolk sac does what?
-helps feed fetus to grow
What is quickening?
-movements are felt from fetus
Thumb sucking begins when?
4 months
When does skin become vulnerable? And what else occurs at this time
at 4.5 months, sleeping waking states also occur.
Vernix is?
layer of fat that protects the skin
What happens at 7 months
growth slows, and
VIABLE (able to survive outside the womb)
Digestive and respiratory systems working
Average length and weight at birth?
20 inches long, and 7lbs heavy (20in x 7lb)
Brain development what 3 major aspects?
- Cell proliferation
- Cell migration
- Cell differentiation
Cell proliferation?
Development of new neurons
Cell migration?
Neurons move to “proper location”
Cell differentiation?
Neurons specialize
Teratogens and 3 important factors that determine severity?
Any environmental agent that causes damage during prenatal period 1) dose 2)heredity 3)timing -what point during pregnancy Embryonic stage is most sensitive
When and why is child most susceptible to teratogens?
Embryonic period when major organs are forming and begin to function (Each organ has specific critical period)
Drugs affecting prenatal development?
Drugs: prescription, non-prescription (advil), psychoactive drugs (act on nervous system) caffeine, alcohol, nicotine, cocaine, marijuana
Other factors affecting prenatal development. IEMMM
Incompatible blood types Environmental hazards Maternal diseases (aids) Maternal nutrition (consumption of folic acid) Maternal age (adolescence, >35 years of age
Describe stage 1 of labor
Cervical dilation
Uterine contractions and ends when the cervical opening is fully dilated. **6-12 hours (16-24 for first time mothers)
Describe stage 2 of labor
Expulsion (babys crowning)
extends from end of the first stage until the baby is completely expelled. **90minutes
Describe stage 3 of labor
Afterbirth
Placenta, umbilical cord, and other membranes expelled ** 2 minutes
APGAR scale is?
1m and 5m after baby is born Appearance (skin tone) Pulse (HR) Grimace (reflexes) Activity (muscle tone) Respiration (breathing)
APGAR scale rating system?
Each factor between 0-2
Good = 7-10
Needs special care= 4-6
Life threatening= < 3
Pre-term/low birth-weight /SGA, what the weights and weeks
Pre-term infants = < 38 weeks
Low birth-weight infants = < 5.5 lbs (2500g)
SGA = 5.5-6.7lbs (2500-3060g)
Very low birth-weight ?
Most vulnerable, < 2.25 lbs (1250g)
What causes pre-term and low birth-weight deliveries?
- Difficulties with mother reproductive system
- Immaturity of mothers reproductive system
- General health of mother
Post-mature babies are?
2 weeks or more overdue
- Blood supply from placenta may be insufficient
- Low blood supply to brain may cause brain damage
- Labor riskier for lg fetus to pass through birth canal
