What is the prenatal period of development?
The process of prenatal development occurs in three main stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is known as the embryonic period, and the time from the ninth week until birth is known as the fetal period.
What are the three stages of prenatal development?
Normal prenatal development lasts about 38 weeks and is divided into three stages: germinal, embryonic, and fetal. During these three stages of gestation, the original single-celled zygote develops into an embryo and then fetus [1, 2].
What is the first stage of prenatal development and how long does it last?
The first 2 weeks of development is the germinal period. The germinal period begins with conception and ends when the blastocyst is fully implanted into uterine tissue. Next, the embryonic period lasts from implantation until about 8 weeks from the time of conception.
What stage of prenatal development does breathing begin?
*Around 18 weeks, fetal movement can be felt. *Around 19 weeks, the fetus can hear. *Around 27 weeks, breathing movements begin in preparation for breathing outside the womb.
Which stage of prenatal development is the shortest 2 points?
The answer is Germinal, because it lasts 0-2 weeks, whereas Embryonic last 3-8 weeks, and and the Fetal lasts 9 weeks- to birth.
What are the 4 stages of embryonic development?
Carnegie Stage Table
| Stage | Days (approx) | Events |
|---|---|---|
| 1 | 1 (week 1) | fertilized oocyte, zygote, pronuclei |
| 2 | 2 – 3 | morula cell division with reduction in cytoplasmic volume, blastocyst formation of inner and outer cell mass |
| 3 | 4 – 5 | loss of zona pellucida, free blastocyst |
| 4 | 5 – 6 | attaching blastocyst |
Which is the first organ to be formed in the developing baby?
The heart is the first organ to form during development of the body. When an embryo is made up of only a very few cells, each cell can get the nutrients it needs directly from its surroundings.
Which is the last stage in pre-embryonic development?
Implantation. At the end of the first week, the blastocyst comes in contact with the uterine wall and adheres to it, embedding itself in the uterine lining via the trophoblast cells. Thus begins the process of implantation, which signals the end of the pre-embryonic stage of development (Figure 28.2.
What is the final stage of embryo?
A blastocyst is then formed and implanted in the uterus. Embryogenesis continues with the next stage of gastrulation, when the three germ layers of the embryo form in a process called histogenesis, and the processes of neurulation and organogenesis follow.
What week is the placenta formed?
In weeks 4 to 5 of early pregnancy, the blastocyst grows and develops within the lining of the womb. The outer cells reach out to form links with the mother’s blood supply. After some time, they will form the placenta (afterbirth). The inner group of cells will develop into the embryo.
How can you tell if fetus is growing?
At about 6 weeks, your baby’s heart beat can usually be detected. After the 8th week, your baby is called a fetus instead of an embryo. By the end of the second month, your baby is about 1 inch long and weighs about 1/30 of an ounce. Your baby’s arms, hands, fingers, feet and toes are fully formed.