What are the 5 stages of prenatal development?
- Germinal stage. Conception occurs when the female egg (ovum) is fertilized by a the male sperm.
- Embryonic stage. The embryonic stage begins after implantation and lasts until eight weeks after conception.
- Fetal stage.
- Congenital abnormalities.
- Maternal derived abnormalities.
What develops first in prenatal development?
The embryo’s gastrointestinal tract, spinal cord, heart, and brain are the first organs to develop. This starts about one week after conception. The placenta also develops in the embryonic stage and it plays a vital role in pregnancy because it carries nutrients, oxygen, and water to your baby.
What are the 3 major stages of prenatal development?
This union marks the beginning of the prenatal period, which in humans encompasses three distinct stages: (1) the pre-embryonic stage, the first two weeks of development, which is a period of cell division and initial differentiation (cell maturation), (2) the embryonic period, or period of organogenesis, which lasts …
What is the stage of infancy?
Infancy is the period from birth through the completion of the 12th month of life.
How many weeks is the zygote stage?
Zygotes divide through a process known as mitosis, in which each cell doubles (one cell becomes two, two becomes four, and so on). This two-week stage is known as the germinal period of development and covers the time of fertilization (also called conception) to the implantation of the blastocyst in the uterus.
What’s the first part of a baby to form?
Just four weeks after conception, the neural tube along your baby’s back is closing. The baby’s brain and spinal cord will develop from the neural tube. The heart and other organs also are starting to form. Structures necessary to the formation of the eyes and ears develop.
Which period begins three weeks after conception?
The beginning of the third week after conception marks the start of the embryonic period, a time when the mass of cells becomes distinct as a human. The embryonic stage plays an important role in the development of the brain. Approximately four weeks after conception, the neural tube forms.
Which comes first embryo or zygote?
From Egg to Embryo First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst. Inside the uterus, the blastocyst implants in the wall of the uterus, where it develops into an embryo attached to a placenta and surrounded by fluid-filled membranes.
What is the correct sequence of prenatal stages of development?
There are three stages of prenatal development: germinal, embryonic, and fetal.