Test 1 Flashcards
How many chromosomes are in a zygote?
46
What is the progression of an embryo’s development?
zygote, embryonic period, fetal period
What happens in the embryonic period?
(wk 1-8)
wk 3: ectoderm, mesoderm, endoderm formed
6 branchial arches
all major systems developing
What is the fetal period?
wk 9 - birth
rabid body growth, slower head growth
Which system is the first one functioning?
cardiovascular - heart circulates blood at 21-22 days
When does the central nervous system begin functioning?
wk 3
What do we know about the respiratory system in embryos?
tracheo-esophageal septum
lungs non-functional during prenatal life
When does the esophagus reach full length?
by wk 7
When are the 6 branchial arches formed?
4 visible by wk 4
6 branchial arches give rise to formation of?
face, neck, nasal cavities, mouth, larynx, pharynx, head & neck muscles, cranial nerves
What is a major embryologic cause of swallowing/feeding problems?
branchial arch anomalies - can result in CNS/structural damage and head/neck malformations
What happens during wks 9-12 of the fetal period?
head makes up one half the length of the fetus
facial features, limbs, feet, hands present
palatal and nasal septum fusion
taste buds present (around wk7)
CNS is functioning
What happens during wks 13-16 of the fetal period?
body length doubles sex organs form ossification of skeleton eyes/ears move closer to normal position pharyngeal swallow begins (as early as 12 wks)
What happens during weeks 17-20 of the fetal period?
pharyngeal swallow strengthens
fetus swallows and digests up to 50% amniotic fluid
suckling begins
alpha fetal protein testing
Weeks 21-25 of fetal period?
substantial weight gain
upper and lower respiratory development
lungs begins to produce surfactant
chance of survival ~24+ weeks with NICU resources @immediate delivery
What happens during wks 26-29 of the fetal period?
primitive reflexes begin in utero
possible that lungs might be functional at 29 weeks
CNS continues to mature: regulates body temp, improves rhythmic breathing
What happens during weeks 30-33 of the fetal period?
33+ weeks usually okay to deliver at local hospital
skin thickens, body lengthens
breathing patterns continue
premature infant still developing coordinated suck/swallow/breathe
Weeks 34 - 36 fetal period?
cusp of premature, might be able to feed orally, breathing okay
body fat ~8%
weeks 37-40 fetal period?
normal gestation, expected delivery
swallowing 450 mL a day
body fat ~16%
7 lbs, 19 in average in weight and length
what are the stages of alertness?
deep sleep light sleep dozing/drowsy quiet alert active alert alert agitated crying
What is “shut down”?
rapid transition from awake to asleep