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 …

Which is the longest of the 3 prenatal stages?

The longest period of prenatal development is the fetal period which begins at the 9th week after conception and lasts until birth. By the 12th week, the genitals have formed. Development of all the structures of the body continues and by the end of the third month, all structures are present although immature.

What are 3 major developments in the germinal period?

The germinal stage involves several different processes that change an egg and sperm first into a zygote, and then into an embryo. The processes include fertilization, cleavage, blastulation, and implantation.

What are the three stages of prenatal development what happens during each stage quizlet?

Prenatal development proceeds through the germinal (first 2 weeks), embryonic (2 weeks to 2 months), and fetal stages (2 months to birth) as the zygote is differentiated into a human organism. The embryonic stage is a period of great vulnerability, as most physiological structures are being formed.

Which is the first period 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 period of prenatal development is the most critical and why?

The embryonic period is the most critical period of development because of the formation of internal and external structures.

What are the 4 stages of embryonic development?

• 1.1 Fertilization.
• 1.2 Cleavage.
• 1.3 Blastulation.
• 1.4 Implantation.
• 1.5 Embryonic disc.

Which of the following correctly lists the stages of prenatal development in order from beginning to end?

Which of the following correctly lists the stages of prenatal development? Germinal, embryonic, fetal. The embryonic stage is the period from implantation until about the eighth week of development.

Which of the following is the correct description of the prenatal development stages?

Which of the following is the correct description of the prenatal developmental stages? Conception begins the germinal period, this is following by the embryonic period, and finally the fetal period. … – It is the transition period between adolescence and adulthood.

What are the stages of prenatal development in psychology?

There are three stages of prenatal development—germinal, embryonic, and fetal.

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What is the germinal period of pregnancy?

The germinal period is the first 2 weeks of prenatal development after conception, which involves rapid cell division and the start of cell differentiation.

Which of the following developments occurs during the germinal period of prenatal development?

The germinal period (about 14 days in length) lasts from conception to implantation of the zygote (fertilized egg) in the lining of the uterus. During this time, the organism begins cell division and growth. After the fourth doubling, differentiation of the cells begins to occur as well.

What is the zygote period?

The zygote begins as a single cell but divides rapidly in the days following fertilization. The zygote’s single cell contains all of the 46 necessary chromosomes, getting 23 from the sperm and 23 from the egg. The zygote phase is brief, lasting only about four days.

What are the 5 stages of conception?

• Conception: From Egg to Embryo. …
• Ovulation. …
• Moving Into the Fallopian Tube. …
• The Sperm’s Long Journey. …
• Fertilization: Sperm Penetrates Egg. …
• The Cells Start to Divide. …
• Implantation. …
• Pregnancy Hormones.

What are the developmental stages?

There are three broad stages of development: early childhood, middle childhood, and adolescence. They are defined by the primary tasks of development in each stage.

What are the 4 stages of embryonic development quizlet?

• Zygote.
• Two-cell stage.
• Morula.
• Blastocyst.
• Gastrula.
• Organogenesis.

What are the three stages in the growth period quizlet?

Terms in this set (18) This period is generally divided into three stages: the germinal stage, the embryonic stage, and the fetal stage.

What are critical periods of development?

A critical period is a time during early postnatal life when the development and maturation of functional properties of the brain, its “plasticity,” is strongly dependent on experience or environmental influences.

What development happens in the third trimester?

During the third trimester, your fetus continues to grow in size and weight. The lungs are still maturing, and the fetus begins to position itself head down. By the end of the third trimester, the fetus is about 19 to 21 inches long and weighs, on average, 6 to 9 pounds.

Why is prenatal period important?

Pre-Pregnancy and prenatal care can help prevent complications and inform women about important steps they can take to protect their infant and ensure a healthy pregnancy. With regular prenatal care women can: Reduce the risk of pregnancy complications.

When does the prenatal period begin quizlet?

The embryonic period of prenatal development occurs from week 3 until week 8.

Which of the following prenatal periods is the shortest quizlet?

• germinal stage. the first-and shortest-stage of the prenatal period, which takes place during the first 2 weeks following conception.
• embryonic stage. the period from 2-8 weeks following fertilization during which significant growth occurs in the major organs and body systems.
• fetal stage.

What is the germinal period quizlet?

Germinal Period. period of prenatal development that takes place in the first two weeks after conception. Fertilization. process where sperm and egg join. Zygote.

Which of the following periods of prenatal development takes place during the first week quizlet?

The first period, the preimplantation period of prenatal development, takes place during the first week after conception.

What is a blastocyst?

By the fifth or sixth day, the fertilized egg is known as a blastocyst — a rapidly dividing ball of cells. The inner group of cells will become the embryo. The outer group will become the cells that nourish and protect it.

What makes up the Chorion?

The chorion is a double-layered membrane formed by the trophoblast and the extra-embryonic mesoderm, which eventually will give rise to the fetal part of the placenta.

What is implantation embryology?

Implantation is a process in which a developing embryo, moving as a blastocyst through a uterus, makes contact with the uterine wall and remains attached to it until birth. The lining of the uterus (endometrium) prepares for the developing blastocyst to attach to it via many internal changes.

How long is each of the three stages of pregnancy?

Conception to about the 12th week of pregnancy marks the first trimester. The second trimester is weeks 13 to 27, and the third trimester starts about 28 weeks and lasts until birth. This slide show will discuss what occurs to both the mother and baby during each trimester.

What does ovulation period mean?

Ovulation is a phase in the menstrual cycle. It occurs at about day 14 of a 28-day menstrual cycle. Specifically, ovulation is the release of the egg (ovum) from a woman’s ovary.

What are the 9 stages of pregnancy?

• Amniocentesis.
• First Trimester Health.
• First Trimester Tests.
• Second Trimester Health.
• Second Trimester Tests.
• Third Trimester Health.
• Third Trimester Tests.
• Ultrasound.