- Introduction
- Rest time! Have fun
- Physics
- Chemistry
- BIOLOGY
- Reaching the age of Adolescence
- CROP PRODUCTION AND MANAGMENT
- Cells : The basic structural unit of life
- Nutrition in human beigns
- RESPIRATION IN HUMAN BEIGNS
- TRANSPORTATION IN HUMAN BEIGNS
- excretory system in human beigns
- NERVOUS SYSTEM
- PHOTOSYNTHESIS
- Respiration in plants
- REPRODUCTION IN PLANTS
- MOVEMENTS IN PLANTS
- Forest our lifeline
- WASTE WATER STORY
- WEATHER,CLIMATE AND ITS ADAPTATION .
- Reaching the age of Adolescence
- Model tests
- Animation time
Reaching The Age Of Adolescence
The period of life, when the body undergoes changes , leading to reproductive maturity , is called adolescence . Adolescence begins around the age of 11 and lasts upto 18 or 19 years of age. Since this period covers the ‘teens’ (13 to 18 or 19 years of age), adolescents are also called ‘teenagers’. In girls, adolescence may begin a year or two earlier than in boys. Also, the period of adolescence varies from person to person. The human body undergoes several changes dur ing adolescence. These changes mark the onset of puberty. The most important change which marks puberty is that boys and girls become capable of reproduction. Puberty ends when an adolescent reaches reproductive maturity.
Changes at Puberty-
Increase in HeightChange in Body Shape
Voice ChangeDevelopment of Sex Organs
Reaching mental & emotional maturity Secondary Sexual Characters-Testes and ovaries are the reproductiveorgans. They produce the gametes,t h a t i s , s p e r m s a n d ova . In girls ,breasts begin to develop at puberty and boys begin to grow facial hair, thatis, moustaches and beard. As these features help to distinguish the male f r o m t h e f e m a l e t h e y a r e c a l l e d secondary sexual characters. Boys also develop hair on their chest. In both, boys and girls, hair grows under the arms and in the region above the thighs or the pubic region.T h e c h a n g e s w h i c h o c c u r a ta d o l e s c e n c e a r e c o n t r o l l e d b yhormones. Hormones are chemicalsubstances. These are secretions fromendocrine glands, or endocrine system.The male hormone or testosteronebegins to be released by the testes att h e o n s e t o f p u b e r t y . T h i s c a u s e schanges in boys about which you havejust learnt, for example, the growth offacial hair. Once puberty is reached ingirls, ovaries begin to produce the femalehormone or estrogen which makes thebreasts develop. Milk secreting glandsor mammary glands develop inside the breasts . T h e p r o d u c t i o n o f t h e s eh o r m o n e s i s u n d e r t h e c o n t r o l o fanother hormone secreted f rom anendocrine gland called pituitary gland.The testes and ovaries secrete sex hormones. You have just learnt that these hormones are responsible for the ma l e a n d female secondary s e x u a l
characters. Further, the sex hormones are under the control of hormones from the pituitary gland . The pituitary secretes many hormones, one of which makes ova mature in the ovaries and sperms form in the testes