Reaching the Age of Adolescence Class 8 PPT

 Page 1


CHAPTER - 10 
 
Reaching The Age Of Adolescence 
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CHAPTER - 10 
 
Reaching The Age Of Adolescence 
1) Adolescence and puberty :- 
 a) Adolescence :-    
        The period of life between 11 years and 19 years when the body  
      undergoes changes leading to reproductive maturity is called  
      adolescence. Between the ages of 11 years and 19 years children  
      are called adolescents. During this period adolescents are called  
      teenagers. 
 b) Puberty :- 
        During adolescence the body undergoes several changes and  
      becomes capable of reproduction. These changes are the  
      beginning of puberty.  
Page 3


CHAPTER - 10 
 
Reaching The Age Of Adolescence 
1) Adolescence and puberty :- 
 a) Adolescence :-    
        The period of life between 11 years and 19 years when the body  
      undergoes changes leading to reproductive maturity is called  
      adolescence. Between the ages of 11 years and 19 years children  
      are called adolescents. During this period adolescents are called  
      teenagers. 
 b) Puberty :- 
        During adolescence the body undergoes several changes and  
      becomes capable of reproduction. These changes are the  
      beginning of puberty.  
2) Changes during  puberty :- 
     The important changes taking place during puberty are :- 
  i) Increase in height. 
 ii) Change in body shape. 
iii) Voice change. 
iv) Increased activity of sweat and sebaceous glands 
iv) Development of sex organs. 
 v) Reaching mental, intellectual and emotional maturity. 
 
a) Increase in height :-   
   By the age of 11 a boy reaches about 80% of his height and a girl 
reaches about 88% of her height. Initially girls grow faster than boys. By 
about 18 years of age both boys and girls reach their maximum height. 
    Generally the height is similar to the parents because it depends on 
the genes inherited from the parents. 
 
Page 4


CHAPTER - 10 
 
Reaching The Age Of Adolescence 
1) Adolescence and puberty :- 
 a) Adolescence :-    
        The period of life between 11 years and 19 years when the body  
      undergoes changes leading to reproductive maturity is called  
      adolescence. Between the ages of 11 years and 19 years children  
      are called adolescents. During this period adolescents are called  
      teenagers. 
 b) Puberty :- 
        During adolescence the body undergoes several changes and  
      becomes capable of reproduction. These changes are the  
      beginning of puberty.  
2) Changes during  puberty :- 
     The important changes taking place during puberty are :- 
  i) Increase in height. 
 ii) Change in body shape. 
iii) Voice change. 
iv) Increased activity of sweat and sebaceous glands 
iv) Development of sex organs. 
 v) Reaching mental, intellectual and emotional maturity. 
 
a) Increase in height :-   
   By the age of 11 a boy reaches about 80% of his height and a girl 
reaches about 88% of her height. Initially girls grow faster than boys. By 
about 18 years of age both boys and girls reach their maximum height. 
    Generally the height is similar to the parents because it depends on 
the genes inherited from the parents. 
 
b) Change in body shape :- 
   During puberty boys have broader shoulders and wider chests due to  
   faster growth of muscles. In girls the breast begins to develop and the  
   region below the waist becomes wider. 
c) Voice change :- 
   During puberty in boys the voice box (larynx) becomes larger and is  
   seen as a swelling in the throat called Adam’s apple and their voice  
   becomes deep and hoarse. In girls the voice box is smaller and their  
   voice is high pitched. Later their voice becomes normal. 
d) Increased activity of Sweat and Sebaceous glands :- 
   During puberty the secretions of the sweat and sebaceous glands (oil  
   glands) increases and many teens get acne and pimples on their face. 
e) Development of  Sex organs :-   
   During puberty in boys the testes and penis develops completely and  
   produces sperms. In girls the ovaries develop completely and  
   produces eggs. 
Page 5


CHAPTER - 10 
 
Reaching The Age Of Adolescence 
1) Adolescence and puberty :- 
 a) Adolescence :-    
        The period of life between 11 years and 19 years when the body  
      undergoes changes leading to reproductive maturity is called  
      adolescence. Between the ages of 11 years and 19 years children  
      are called adolescents. During this period adolescents are called  
      teenagers. 
 b) Puberty :- 
        During adolescence the body undergoes several changes and  
      becomes capable of reproduction. These changes are the  
      beginning of puberty.  
2) Changes during  puberty :- 
     The important changes taking place during puberty are :- 
  i) Increase in height. 
 ii) Change in body shape. 
iii) Voice change. 
iv) Increased activity of sweat and sebaceous glands 
iv) Development of sex organs. 
 v) Reaching mental, intellectual and emotional maturity. 
 
a) Increase in height :-   
   By the age of 11 a boy reaches about 80% of his height and a girl 
reaches about 88% of her height. Initially girls grow faster than boys. By 
about 18 years of age both boys and girls reach their maximum height. 
    Generally the height is similar to the parents because it depends on 
the genes inherited from the parents. 
 
b) Change in body shape :- 
   During puberty boys have broader shoulders and wider chests due to  
   faster growth of muscles. In girls the breast begins to develop and the  
   region below the waist becomes wider. 
c) Voice change :- 
   During puberty in boys the voice box (larynx) becomes larger and is  
   seen as a swelling in the throat called Adam’s apple and their voice  
   becomes deep and hoarse. In girls the voice box is smaller and their  
   voice is high pitched. Later their voice becomes normal. 
d) Increased activity of Sweat and Sebaceous glands :- 
   During puberty the secretions of the sweat and sebaceous glands (oil  
   glands) increases and many teens get acne and pimples on their face. 
e) Development of  Sex organs :-   
   During puberty in boys the testes and penis develops completely and  
   produces sperms. In girls the ovaries develop completely and  
   produces eggs. 
f) Reaching Mental, Intellectual and Emotional maturity :- 
   During puberty boys and girls mental, intellectual and emotional  
   development takes place. They become more independent, self  
   conscious and their way of thinking changes. 
3) Secondary Sexual Characters :- 
   Secondary sexual characters are the changes which takes place  
   during puberty.  
   In boys hairs begin to grow on the face and they develop beards and  
   moustaches. Hair also grows in the chest, armpits and pubic region.  
  The testes starts to produce sperms. 
   In girls their breast develops and hair grows in the armpits and pubic  
   region. The ovary starts to produce eggs. 
  These changes are controlled by chemical substances called  
   hormones produced by endocrine glands. 
  The male hormone which controls secondary sexual characters is  
  called testosterone. It is produced in the testes. 
  The female hormone which controls secondary sexual characters is  
  called estrogen. It is produced in the ovary. 
  The production of these hormones is controlled by another gland  
  called pituitary gland.