The Pattern of Human Growth
1. Growth is the characteristic of all living things.
2. Changes that take place in organisms from birth to adulthood are referred to as growth and development.
3. Growth is the permanent and irreversible change in shape, and increase in mass and size acquired by an organism in the course of its development.
4. As we grow, we not only increase in size and shape, specialisation of cells occur too. Each group of cells in our body become specialised and perform a particular function.
Measuring Growth Rate
1. Growth is normally measured by recording changes in an organism at suitable intervals over a period of time.
2. Height or weight are two common characteristics used to measure growth rate.
3. Other than height and weight, the length of the human arm and the size of the human head can be used to measure growth rate too.
Growth Pattern In Human Beings
1. If the measurements of height or weight are plotted against time, a growth curve is obtained.
2. Despite whatever measurements they are, the general pattern of the growth curve turns out to be the same.
3. Human life cycle can be divided into five stages, namely infancy, childhood, adolescence, adulthood and senescence.
4. The period of infancy encompasses the first 2 years of life.
5. Childhood is the period of growth and development, extending from infancy to adolescence.
6. Adolescence is the stage where a person passes from childhood to a sexually mature adult. It is a period of rapid physical growth and development.
7. Growth tends to be fast at the infancy stage, then it slows down during early childhood.
8. Growth rate speeds up again during adolescence and finally slows down as adulthood is reached, giving an S-shaped curve as shown in Figure 5.2.
9. Hence, the growth curve enables us to determine the growth rate of human beings at different stages of the human life cycle.
10. In human beings, growth stops when maturity is reached.
11. As we grow, our body's proportions change too. For example, the head of a newborn baby is about one quarter of the total body length, whereas the head of an adult is only one-eighth of the body lenght.
12. Figure 5.3 shows the relative proportions of the body and skull from infancy to adulthood.
Growth Curve For Males And Females
1. From infancy to the age of 12, the growth rate of males is higher than females. This is shown in Figure 5.4.
2. However, between the ages of 12 and 15, females tend to grow faster than males.
3. This is because puberty begins earlier in females.
4. Puberty is the stage of early adolescence when the secondary sex characteristics become noticeable and the sexual organs become functional.
5. Under the influence of hormones, females experience puberty earlier than males by nearly 2 years.
6. During this period, females are temporarily taller than males.
7. Once puberty begins in males, the growth rate of males is higher.
8. By the time growth is completed at the end of adolescence, males are generally taller than females.
9. We reach the peal of our physical potential at adolescence and early adulthood.
10. A healthy diet, regular exercises and other beneficial lifestyle habits can keep a person vigorous for decades of adult life.
11. However, after the age of 40, our body begins to undergo structural changes and there is a gradual loss of efficiency in bodily functions. This process is called senescence or simply aging.
Effects Of Nutrition On Growth.
1. Human beings require important nutrients for satisfactory growth.
2. Nutrients are chemical substances which organisms need for releasing energy, for warmth, for growth and repair, and to carry out all life processes.
3. Proteins, carbohydrates, fats, vitamins and minerals are essential nutrients that are needed by the body for growth, repair and maintenance of body tissues, and regulation of body functions.
4. These nutrients are usually provided in food.
5. Protein is one of the most important nutrients.
6. It is needed for growth, body building and repair of worn-out or damaged tissues.
7. Meat, eggs, fish, milk and beans are food rich in proteins.
8. Children with a diet lacking in proteins may be prone to growth retardation.
9. Carbohydrates and fats provide energy to our body.
10. Rice, potato, bread, sugar and honey are rich in carbohydrates.
11. Example of food which are rich in fats are butter, lard, margarine, corn oil, peanut oil and cod-liver oil.
12. Vitamins are nutrients needed in small amounts for good health.
13. There are many kinds of vitamins, such as vitamin A, B, C, D, E and K.
14. A lack of vitamins in our diet may cause deficiency disease. Severe deficiency can cause death.
15. Minerals are essential substances which are required to regulate the metabolism of the body.
16. They are needed in small amounts for the healthy growth of organisms and for the construction of certain tissues.
17. Some important mineral elements are calcium, phosphorus, iron, zinc, sodium, magnesium and iodine.
18. Diet refers to all the food we eat. A balanced diet is important for children's physical and mental development.
19. A diet containing the right amounts of all the groups of food substances is known as a balanced diet.
20. The amounts of different kinds of food required by an individual is dependent on his/her age, sex, physical activities and occupation.
21. For example, a child needs more protein for active growth than an adult.
22. A lack of any of the essential nutrients can lead to poor health, low resistance to diseases and retarded growth.
23. Other than a balanced diet, exercising regularly, not smoking, not drinking and not abusing drugs are equally important to help us stay healthy and happy.