Question

Describe the different developmental age periods:

Germinal

Embryonic

Fetal

Neonatal

Infancy

Toddler

Preschool

Middle childhood

Prepubertal

Adolescence

Answer 1

Ans) 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.

- Three major developments in the germinal period- rapid cell division and the beginning of cell differentiation. -About a week after conception, blastocyst, forms two distinct parts a shell that will become the placenta.

Embryonic Period
Think of Steve and Jennifer's baby as spending the germinal period looking for a place to live. Now that she's found her place, she's ready to start organizing for the work she has ahead of her.

This is the embryonic period of prenatal development. This stage lasts from implantation until about 8 weeks from the time of conception (or the 10th week of pregnancy). This is the most important time of prenatal development because the embryo is developing the foundations for a healthy baby.

The blastocyst that implanted in the uterus continues to divide rapidly after implantation. Through a process called differentiation, cells begin to take on different functions. One of the first examples of this is a division between the cells that will make up the placenta and the cells that will make up the baby.

After this, a process called gastrulation forms three layers called germ layers. The outer layer is called the ectoderm, the middle layer is called the mesoderm, and the inner layer is called the endoderm.

Each germ layer will differentiate into different structures. The ectoderm will form many outer tissues such as skin and hair, as well as most of the nervous system tissues - including the brain. The mesoderm will form tissues inside the body such as the lungs, bones, and muscles - including the heart. The endoderm will form tissues such as the digestive tract and bladder, as well as other internal organs.

All of the essential structures have been formed (both inside and outside) by the time the embryonic period comes to an end. The new title of fetus is now given to the embryo.

Embryogenesis is a term that can be used to describe all of the processes of embryo development up until the time it becomes a fetus.

Fetal Period
Remember Steve and Jennifer's baby? We said that the germinal period was like their baby finding a place to live, and that during the embryonic period, she was organizing her space. During the final period of development, she is putting on the finishing touches in preparation of the big event.

This final stage of development is called the fetal period of development. This stage takes place from the end of the embryonic period until the time of birth (or the 10th to 40th weeks of pregnancy).

Infancy
Birth-two years. While the infant is dependent on adults for most things, many psychological characteristics are rapidly developing. During this stage, the bond that develops between the infant and their primary caregiver is important in terms of the infant's later emotional development.

Childhood
Two-ten years. During this stage, children become increasingly independent from their parents as they learn to do things themselves and gain more self-control. During this stage, children's cognitive skills develop and they also begin to develop an understanding of what is right and wrong.

Adolescence
Ten-twenty years. The onset of puberty marks the beginning of adolescence. It is dominated by seeking independence from parents and developing one's own identity. Compared to the child, an adolescent's thought processes are more logical, complex and idealistic.

Early Adulthood
Twenty-forty years. This is the stage of establishing personal and financial independence and establishing and consolidating a career. For many, it is also the time in which individuals select a partner, develop an ongoing intimate relationship and begin a family.

Middle Age
Forty-sixty five years. This is a period of expanding social and personal involvements and responsibilities, advancing a career, and supporting offspring in their development to becoming mature individuals.

Older Age
Sixty five years plus. A period of considerable adjustment to changes in one's life and self-perceptions. For many older people, this is a very liberating time when they no longer have the day-to-day responsibility of looking after their children or working.