Meaning of Physical Growth and Development
Physical growth and development refers a process which brings bodily and physiological changes, internal as well as external in an organism from the conception till his death. Generally these changes take place in the following dimensions:
1. In his gross physical structure or physique:- It involves changes in terms of height, weight, body proportions and general physical appearance.
2. In his internal organs:- It involves changes in the functioning of glands, nervous system and other body systems circulatory, respiratory. digestive, muscular, lymphatic and reproductive.
The process of physical growth and development plays a significant role in the proper adjustment and progress of an organism. In the beginning the infant is quite helpless. He depends upon his parents and other members of the family for the satisfaction of his bodily needs. As a result of the changes brought by physical growth and development, his body organs become adaptable to his increasing body needs and gradually he is developed into a mature responsible adult.
The General Pattern of Human Physical Growth and Development
Although there are wide individual differences among the human beings and therefore it is not possible to describe a perfect general pattern of the growth and development, yet physical growth and development seems to follow, to some extent, a general pattern which can help us to think about some definite structural changes in the case of normal children at each stage of their growth and development.
Below we try to summarize this general pattern of growth and development along with definite structural changes.
1. Increase in Height and Weight:- On the average, at birth a baby is about 19 or 20 inches in height and between 7 and 8 pounds in weight. boys being slightly taller and heavier. During the first two years, there is rapid increase in both height and weight. There is a steady and slower growth from the third year till the on-set of puberty. By five years the height of the child, approximately, becomes almost doubled and he acquires almost five times his birth weight.
During the period of adolescence we again find a sudden increase in both height and weight. Girls reach puberty about a year or two earlier than boys do. Therefore, between the age 12 to 14 they are found slightly taller and heavier than boys. But they are again surpassed by the boys. By the end of adolescence. the young men are generally higher and heavier than the young women. Generally both men and women get their maximum height and weight upto the end of adolescence. But there are very much variations in weight as it is more susceptible to environmental influences. Therefore, it is no surprise to note the sudden increase or decrease in weight in later years after attaining maturity.
Weight of the brain increases rapidly in the early years of life. By the time the child completes the age of four his brain gains almost 80 per cent of its final weight, another 10 per cent being added by the time he completes his eight years. By the 20th year, the brain gains almost all its weight.
2. Changes in Body Proportions:- The child does not only grow in size but also a marked change in the proportion of the different parts of the body. For example, the head constitutes about one-fourth the height of the body at birth, its size is relatively much larger than the arms and legs. As the child grows older, the proportion of the head decreases and by the end of adolescence it becomes one eighth of the body. In addition to head, the other body parts, legs, arms, torso etc. also show change in proportions as the child requires them more and more in his adaptation to coming life.
3. Anatomical Growth and Development:- The bones of a child are not smaller in size than the bones of an adult, but they differ also in composition. The child's bones contain, relatively, a great amount of water and smaller quantity of mineral matter than do those of the adult. They are more soft and more blood flows through them them than through the bones of an adult. This accounts for their greater reliability. But it also increases the chances of bones deformities and infection.
As regards the eruption of teeth, it has been found that most of the children acquire their milk teeth by the time they are two years of age. Near the end of the fifth year, the permanent teeth begin to appear the growth of which acquires a long time. The last four of the permanent teeth. the wisdom teeth, erupt between the age of seventeen and twenty five years, if they appear at all. Girls usually show more advanced teeth growth than the boys except in the case of wisdom teeth, where boys are usually ahead of the girls.
4. Growth and Development of Internal Organs:- From birth onward, the internal organs of the child's body undergo constant development. As a result the child's body 5 years show desirable change in order to satisfy the growing needs. Below we consider the growth and development of these internal organs.
(i) Nervous System:- It show a rapid growth during the prenatal period and the first four years after birth. Before birth the development consists primarily of increase in the number and size of nerve cells. Because no new cells are formed after birth, therefore the development in the first four years consists of the development of immature cells present at birth. After the age of 4 years the growth of the nervous system proceeds at a relatively slow rate.
(ii) Muscular System:- Muscular system also shows a remarkable. development, though no new muscle fibers develop after birth. The muscles of the child are more delicate and less firmly attached to the bones than are adult muscles. But gradually the muscles get themselves changed in shape, size and composition and become firmer and stronger.
(iii) Circulatory and Respiratory Systems:- Lungs as well as heart are very small in early childhood but gradually they grow in volume as well as in weight and reach to the maximum upto the end of adolescence. They also show desirable improvement in their functioning. The veins and arteries do not follow the same growth patterns as that of the heart and lungs. Prior to adolescence, they grow rapidly, whereas they show little growth during adolescence.
(iv) Digestive System:- The young child has a small tubular shaped stomach i comparison with the bag like shapes stomach of the adults which not only holds a large amount of food but which also empties more slowly. Therefore they require more feeding in the earlier years of their life than they will need later. In addition to the greater quantity of food, they need food with essential energy value for their rapid growth and development.
(v) Lymphatic System:- It is involved in the elimination of waste and the destruction of bacteria in the body. From birth onward this system shows the sign of rapid development until it reaches to its maximum between the age of 11 and 12 years, when the death rate is about the lowest. After 12 years it decreases rapidly.
(vi) Reproductive System:- The development of sex organs shows it peculiar trend in contrast with the overall growth and developmental pattern. Their rate of development is very slow during early childhood but picks up its speed as the child advances towards adolescence and becomes almost developed, upto the end of adolescence.
The minute observation of the above mentioned pattern can reveal the following important facts regarding the general trend of physical growth and development:
- It is very rapid from birth to the age of two or three years.
- Then, it continues at a diminished rate till the beginning of adolescence.
- The first three years of adolescence are marked as the years of rapid growth and development.
- This is followed by a period of slow growth and development to the time of maturity.
Factors Affecting the Physical Growth and Development
The physical growth and development of an individual is conditioned by both heredity and environment. Some of the important hereditary and environmental factors which influence the process of physical growth and development are:
- The traits and characteristics inherited at the time of conception.
- Single birth or multiple births,
- The physical as well as mental health of the mother during pregnancy.
- Nutrition received by the embryo within the womb of the mother.
- Normal or abnormal delivery.
- Conditions and care at the time of delivery.
- Look after of the baby and its mother.
- Nutrition received by the child after birth.
- Presence or absence of physical defects.
- The living conditions physical, social and cultural.
- The opportunities of recreation, self expression, play and exercise,
- Presence or absence of illness and diseases.
- Emotional and social adjustment of the child. sleep.
- Adequate or inadequate rest and 15. Proper or improper medical care.