Ears
4 1/2 to 20 weeks
Teeth
6 3/4 weeks to full term
palate
6 3/4 to 16 weeks
upper limbs
4 1/2 to 9 weeks
lower limbs
4 1/2 to 9 weeks
external genitalia
7 weeks to full term
heart
3 1/2 to 9 weeks
eyes
4 1/2 weeks to full term
central nervous system
3 weeks to full term