Final answer:
The three stages of prenatal development are the germinal stage (weeks 1-2), embryonic stage (weeks 3-8), and fetal stage (week 9 to birth). Each stage is characterized by rapid development, organ formation, and growth, finally leading to a functioning fetus ready for birth.
Step-by-step explanation:
Stages of Prenatal Development
The three stages of prenatal development are: germinal, embryonic, and fetal.
Germinal Stage (Weeks 1-2)
Beginning at fertilization, the germinal stage encompasses the first two weeks of development. At conception, a sperm and egg unite to form a zygote that begins rapid cell division. The zygote moves towards the uterus and divides into many cells, known as blastomeres, without increasing the total volume of the conceptus.
Embryonic Stage (Weeks 3-8)
Following successful implantation into the uterine wall, the embryonic stage commences. During this time, significant body structures and organ systems begin to form, and the neural tube will develop into the brain and spinal cord. By the end of the embryonic stage, rudimentary forms of all major organ systems are established.
Fetal Stage (Week 9 to Birth)
The fetal stage lasts from the ninth week after fertilization up to birth. Rapid growth and maturation of the body, brain, and organs characterize this stage, and by the end, most organs are functional and ready for life outside the womb.
Throughout each stage, prenatal care is vital to reduce health risks for both the parent and the developing baby.