Fetal Development Flashcards
PRE-EMBRYONIC STAGE
ZYGOTE
Fertilization through week 2
EMBRYONIC STAGE
EMBRYO
weeks 3 - 8
Most critical and main organs develop, very susceptible to teratogens
FETAL STAGE
FETUS
Week 9 - birth
Refinement of system
MAJOR SYSTEMS
Week 6heart beats regularly and lungs are forming
Week 8development of facial features
**Week 20 **vernix and lanugo present
VERNIX
white cheese type substance on babies skin
LANUGO
fine hair that is on ears, shoulder, cheeks, etc
L/S RATIO
2:1
Lecithin-Sphingomyelin (surfactant) important in lung maturity
Week 38
TERATOGENS
ETOH, smoking, cocaine, marijuana, infections
TORCH VIRUSES
Cytomegalovirus, herpes, HIV, Rubella, Syphillis, Toxoplasmosis, Varicella
A/B
DRUGS
Safe
C
DRUGS
OK
D/X
DRUGS
UNSAFE
DIZYOGOTIC
fraternal twins, can be the same or different sex
2 placentas, 2 amnions and corions
**
MONOZYGOTIC
identical twins, always the same sex
one fertilized egg that divides May have 2 placentas, amnions and corions but this depends on when the fertilized egg divided
CONJOINED
always monozygotic twins
Divsion of fertilized egg is not completed, has to be a C section