What is Gestation Period?
- The period between conception and birth is called gestation.
- In humans gestation takes nine months (40 weeks).
- The embryo differentiates into tissues and organs during this period.
Week 1 to 3:
- Zygote divides to form blastocyst.
- Implantation takes place.
- The three germ layers form endoderm, mesoderm and ectoderm.
- Nervous system starts to form.
Week 4 to 7:
- Development of circulating and digestive systems.
- Further development of nervous system, formation of sensory organs,
- All major internal organs are developed.
- At week 5, heartbeat starts.
Week 8 to 24:
- All organs well developed including sex organs.
- Hair, finger and toe nails grow.
- Foetus move and eyelids open.
Week 25- 30:
The fully developed foetus responds to touch and noises and moves vigorously.
The head turns and faces downwards ready for birth.
- Foetus increases in size.
- Birth occurs.