There are three stages of prenatal development:
germinal, embryonic, and fetal
.
What is the most important stage of prenatal development?
The embryonic period
is the most critical period of development because of the formation of internal and external structures. The critical periods of development for the organs are also discussed in the section on specific organ development.
What are the stages of pregnancy development?
It is divided into three stages, called trimesters:
first trimester, second trimester, and third trimester
. The fetus undergoes many changes throughout maturation.
What are the four stages of embryonic development?
- Germinal stage. 1.1 Fertilization. 1.2 Cleavage. 1.3 Blastulation. 1.4 Implantation. 1.5 Embryonic disc.
- Gastrulation.
- Neurulation.
- Development of organs and organ systems.
When do you start to feel pregnant?
It takes
about 2 to 3 weeks after sex
for pregnancy to happen. Some people notice pregnancy symptoms as early as a week after pregnancy begins — when a fertilized egg attaches to the wall of your uterus. Other people don’t notice symptoms until a few months into their pregnancy.
What is the first stage of pregnancy?
For a lot of people, the first sign of pregnancy is
a missed period
. Most pregnancy tests will be positive by the time you’ve missed your period. Other early pregnancy symptoms include feeling tired, feeling bloated, peeing more than usual, mood swings, nausea, and tender or swollen breasts.
What are the 3 major stages of prenatal 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
.
Which trimester is the most critical for fetal development?
The first trimester
is the most crucial to your baby’s development. During this period, your baby’s body structure and organ systems develop. Most miscarriages and birth defects occur during this period. Your body also undergoes major changes during the first trimester.
What is the critical period during pregnancy?
In general, major defects of the body and internal organs are more likely to occur
between 3 to 12 embryo / fetal weeks
. This is the same as 5 to 14 gestational weeks (weeks since the first day of your last period). This is also referred to as the first trimester.
What is the correct order of embryonic development?
Hence the correct answer is ‘C’ i.e,
Zygote-morula-blastula-gastrula-embryo
. Note:All cleavage divisions are mitotic and resultant daughter cells are blastomeres.
What are the blastula stages?
An early stage of embryonic development in animals. It is produced by cleavage of a fertilized ovum and consists of a spherical layer of around 128 cells surrounding a central fluid-filled cavity called the blastocoel. The blastula
follows the morula and precedes
the gastrula in the developmental sequence.
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 are some unusual signs of early pregnancy?
- Nosebleeds. Nosebleeds are quite common in pregnancy due to the hormonal changes that happen in the body. …
- Mood swings. …
- Headaches. …
- Dizziness. …
- Acne. …
- Stronger sense of smell. …
- Strange taste in the mouth. …
- Discharge.
How can you tell if your pregnant by touching your stomach?
Your touch should be firm but gentle. Walk your fingers up the side of her abdomen (Figure 10.1) until you feel the top of her abdomen under the skin. It will feel like a hard ball. You can feel the top
by curving your fingers gently into the abdomen
.
Do and don’ts in 1st month of pregnancy?
Eat a variety of healthy food that is rich in iron, calcium and folate
. Small frequent meals at regular intervals, along with an adequate liquid intake, are essential during the first trimester. Drink at least eight glasses (1.5 litres) of fluid every day, mostly water. It’s very important to stay hydrated.
