Online notes for Class 8 Science : Age of Adolescence
Takshila Learning brings a whole collection of the important topics and subject matter for Class 8th Science. We aim to provide the complete details to help students build a robust base and excel in exams.
In this article, we will discuss Adolescence and Puberty.
Adolescence and Puberty
The transition from the childhood to adulthood is called adolescence.
As per WHO (world health organization), adolescence is a period of life between 10 to 19 years of age.
Adolescence is the period where the female and male reproductive organs are maturing and start to function. Female reproductive organs began to produce egg or ovum and male reproductive organs began to produce sperms. Another change is the development of breast in girls and facial hair in boys. This characteristic distinguishes between males and females.
Puberty is the time of growth in which an individual becomes sexually mature, achieves reproductive maturity. Let’s discuss the physical changes takes place in girls and boys during puberty.
Physical change
- Reproductive organs development – Ovaries are completely develop and start producing mature eggs in girls, and in boys the testes and penis develop and start producing sperms.
- Enlargement of breasts – Mammary glands develop, breasts increase in size and these glands are milk-producing
- Increase in height and weight – There is a rapid increase in height and weight in both girls and boys.
- Change in body shape – In boys, the muscles develop, shoulders and chest broadens. In girls, the hips broaden and pelvic region widens.
- Change in voice – The voice box increases in size during puberty, which changes the voice.
Menstrual cycle
The cycle of producing and releasing mature ovum along with associated changes in the ovaries and uterus is called menstrual cycle. It reflects that the female is completely matured and organs are developed to have a baby.
- The pituitary gland discharges a hormone that fuels the ovaries to release a mature ovum. The two ovaries take turns to produce an egg. An ovum is released every 28 days.
- The ovaries release oestrogen and progesterone which changes the lining of the uterus and prepare for pregnancy possibility.
- The ovum then moves to fallopian tube.
- In the absence of fertilization by the sperm, it dies and starts collapsing and the hormone level drop.
- The lining of the uterus starts breaking along with the loss of blood.
An adolescent girl’s first menstruation is called Menarche. At the age of 45 to 55 years, the ability to reproduce decreases and the menstruation stops. This process is called Menopause.
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