PHASE OF DEVELOPMENTAL AND DEVELOPMENT TASKS

Human development characteristically passes through different stages. These stages are orderly and sequentially linked with the preceding and succeeding stages.Features unique to each stage, change from stage to stage. They also vary from person to person thus making us unique in our own way. Very broadly the stages of development may be categorized in two main types:

PHASE1: PRENATAL DEVELOPMENT (BEFORE BIRTH)

a)The period of the zygote -(from fertilization to 2 weeks.)

b) Period of the embryo-(2 weeks to 2 months.)

C) Period of the fetus-(2 months to birth).

PHASE1 II. POSTNATAL DEVELOPMENT BEFORE BIRTH)

a) Infancy (- Birth to l year)

b) Early childhood (  1-3 years)

c) Preschool.( - 3-6 years)

d) School childhood (- 6-12 years-)

e) Adolescence (12-20 years)

f) Young adulthood -( 20-30 years)

g) Adulthood  -( 30-50 years)

h) Mature adult - (50-65 years)

i) Aging adult - (65 above)

I. PRENATAL DEVELOPMENT (BEFORE BIRTH)

a).The period of zygote:

It continues to move down the ovarian tube or oviduct to the uterus. For 4-5 days it floats freely in the uterine cavity. Around the 10thday after fertilization the zygote digs into the wall of the uterus and attaches itself firmly, a process called implantation. The wall of the uterus envelops it. Rapid mitotic cell division takes place and the single cell zygote after repeated divisions resembles a ball with two layers of cells.

b).The period of the embryo:

It extends from 2 weeks to 2 months. During this time the embryo is like a miniature human being. Cell differentiation takes place, that is, from one cell, different types of cells arise. External features such as head, face, hands, fingers, legs can be clearly seen and interior organs such as heart lungs and brain are formed. The embryo turns within the uterus and the heart beat can be heard. The first twelve weeks are very crucial because, it is during this period, the important organs are formed.

c).The period of the fetus:

It extends from the beginning of the third month till birth. The body proportions increase as growth' continues. Activity of the fetus can be felt. All the internal organs are formed and by 5'" month they assume actual proportions. Between 2-4lh month the nervous system develops. On completion of 9 months or 270 days, the fetus is ready for birth.

II. POSTNATAL DEVELOPMENT (BEFORE BIRTH)

a).Infancy (0 to 1 years)

From birth up to the one year of life, the stage is known as infancy. Babies grow very rapidly in size during their first years. The acquisition of motor skills like holding things, crawling, waliking proceeds from simple to complex.

b) Early childhood (1to 3 years)

The early childhood period encompasses several quite distinct phases: from 'conception to birth' and from 'birth to 3 years', with emphasis on the first 1,000 days (from conception to 24 months), followed by the 'preschool and pre-primary years (3 years to 5 or 6 years, or the age of school entry).

C).Pre-school childhood (3-6 years)

The growth in height is not as rapid during this stage as it is in infancy. Children improve eye, hand and small muscle coordination. For example they can draw a circle, pour fhuids into a bowl, button and unbutton clothes, and language development is rapid

d). School childhood (6-12 years - Primary school years)

School children between the age of 6 to 12 years look much taller and thinner. Children exhibit rapid gains in strength and swiftness. They achieve new motor skills and their competence becomes more pronounced in all areas of development.

e).Adolescence (12-20 years)

It is the span of year between childhood and adulthood which begins at puberty. This is the period of rapid physiological growth. There are a number of psychological changes which also take place. Children jump rope, bicycle, ride horses, dance and indulge in all possible games. Cognitively they are more agile and social relationships become important. But the hallmark of this stage is the search for identity. A number of psychological changes also take place. Given sex-role expectations, girls attach greater importance to good interpersonal relationships and the family while boys emphasize the importance of their own social prestige and career.

f). Adulthood (20-65+ years)

For better understanding, adulthood can be divided into three stages. These are:

(g) Young adulthood (20-50 years)

(h) Mature adulthood or the Middle years (50-65 years)

(i) Aging adulthood (65+ years)

Strength and energy characterize this time of life from the middle twenties when most bodily functions are fully developed, until about the age of 50. Thereafter there is gradual decline in energy level.