Germinal
Conception to 2 weeks, lasts until zygote becomes implanted.
Embryonic
3-8 weeks, implantation to cell division, cell migration, cell differentiation, and cell death
Fetal
9 week to birth.
Conception
Gametes combine
Zygote
Fertilized egg cell
Embryo
development 3-8 weeks
Fetus
Developing 9th week to birth
Cell Development
Mitosis, Cell migration, cell differentiation, apoptosis
Mitosis
Cell division splits in two identical daughter cells
Apoptosis
Genetically programmed cell death.
ex. finger development
4th day of conception
Development of inner mass cells (twins start to develop)
General tendency
cephalocaudal development (head first, hand/foot last)
4 weeks
- face begins to emerge
- heart is visible and functioning
- arm bud visible, leg bud less distinct
5.5 week
nose, mouth, and palate start to differentiate
8.5 week
nose and mouth fully formed
Clef Palate
9 week
- Eyes/ears form
- internal organs present
- sexual differentiation
- ribs, fingers, toes and nails
11 week
- Adult shaped heart
- developing spine and brain divisions
16 week
- Kicks
- External genitalia (gender reveal)
18 week
Sucking thumb
20 week
- Facial expressions
- weight gain (less movement)
28 week
- Brain/lungs sufficiently develop (survive premature birth)
- REM sleep
- auditory system functioning
