Reaching the Age of Adolescence (Class 8 Science)

• Adolescence: It is the period of life (usually starting around 11 years and lasting up to 18 or 19 years) when the body undergoes changes leading to reproductive maturity. Teenagers are called adolescents.
• Puberty: The specific physical changes that happen during adolescence, marking the time when the human body becomes capable of reproduction.

1. Increase in Height: The most visible change is a sudden, rapid increase in height due to the elongation of arm and leg bones.
2. Change in Body Shape: In boys, shoulders broaden and chest widens. In girls, the region below the waist becomes wider.
3. Voice Change: The voice box (Larynx) grows larger. In boys, the growing voice box can be seen protruding from the throat (called the Adam's Apple), making their voice deep and hoarse.
4. Development of Sex Organs: Male and female reproductive organs completely mature. Females begin the process of menstruation.

All these changes are controlled by chemical messengers called Hormones, secreted by Endocrine glands.

• Testosterone: The male hormone responsible for facial hair (mustaches and beards).
• Estrogen: The female hormone responsible for breast development.