Page 193 - Health, Population and Environment Education 9

b. Change in weight
There is increase in size and length of bones as well as deposition of fats in different parts
of body in both boys and girls. Hence, both of them gain remarkable weight in the body.

c. Change in voice
In adolescence, the voice of boys become hoarse and rough whereas girl’s voice become
soft and sweet.

d. Change in bodily proportion
Different body organs grow and attain full size by the
end of adolescence. There is broadening of chest, increase
of body strength, development of thigh, extension of
stomach and its perimeter, development of food pipe,
liver, wind pipe, heart, etc.
Fig: 7
e. Development of secondary sexual characteristics
Those characteristics which are developed with the
development of reproductive system, its organs and their
functions are called secondary sexual characteristics.
During adolescence, there is development of secondary
sexual characteristics in both boys and girls. In boys, there
is appearance of beard, mustache, hairs in armpit, public
region, limbs, etc. whereas in females, there is appearance
of hairs in armpit, public region, enlargement of breasts, Fig: 8
starting of menstruation cycle, etc.

f. Growth of sex organs
Different sex organs in boys and girls grow and they attain full size by the end of
adolescence.

g. Physiological development
In adolescence, glandular system becomes active and there is secretion of different
hormones as well as enzymes which affect in the functioning of body. Similarly, other
systems like circulatory system, digestive system, respiratory system, etc. also develop
and they start to function well.

B. Mental changes
There is development of nervous system and intellectual activity during adolescence. As
a result, various mental changes take place. Some of the major mental changes during
adolescence are described as follows:

a. Ability to generalize facts
During childhood, children can generalize the facts or things in a concrete way but the
adolescents can generalize facts or things in an abstract way.

GREEN Environment Population and Health Education Book-9 193