Reaching the Age of Adolescence

Adolescence and Puberty

Introduction

• Animals, including humans, can reproduce only after growing up to a certain age.
• This chapter will discuss the changes in the human body that allow reproduction.
• Hormones play a key role in these changes.

Adolescence and Puberty

• Example: Boojho’s 12th Birthday
  • Boojho’s friends had grown taller and some had started developing facial hair.
  • These changes are part of growing up and indicate the transition from childhood to adulthood.
• Understanding Adolescence:
  • A natural process where the body undergoes changes.
  • Leads to reproductive maturity.
  • Typically begins around age 11 and lasts until 18 or 19.
  • Adolescents are also called teenagers (ages 13 to 19).
  • For girls, adolescence may start a year or two earlier than for boys.
  • The duration of adolescence can vary for each person.
• Puberty:
  • Part of adolescence.
  • The body undergoes several changes, marking the start of puberty.
  • Boys and girls become capable of reproduction during puberty.
  • Puberty ends when an adolescent reaches reproductive maturity.

Changes at Puberty

A. Increase in Height

• Key Change: Sudden increase in height.
• Why: Long bones (arms and legs) elongate.
• Comparison: Initially, girls grow faster but by 18, both boys and girls reach their maximum height.
• Growth Patterns: Some grow quickly at puberty, then slow down; others grow gradually.
• Body Proportion: Arms, legs, hands, and feet may look oversized but will become proportionate over time.
• Genetics: Height is influenced by parents’ genes.
• Nutrition: Important to eat well for proper growth of bones and muscles.

B. Change in Body Shape

• Boys: Broader shoulders and wider chests.
• Girls: Region below the waist becomes wider.
• Muscle Growth: More prominent in boys than girls.

C. Voice Change

• Voice Box Growth: At puberty, the larynx grows, more in boys, leading to a deep voice.
• Adam’s Apple: Protruding part of the throat in boys.
• Voice Cracking: Temporary hoarseness as the voice box grows.

D. Increased Activity of Sweat and Sebaceous Glands

• Sweat and Oil Glands: Increase in activity.
• Common Issue: Acne and pimples due to more oil production.

E. Development of Sex Organs

• Boys: Testes and penis develop, testes start producing sperms.
• Girls: Ovaries enlarge, eggs mature and start being released.

F. Mental, Intellectual, and Emotional Maturity

• Changes in Thinking: Adolescents become more independent and self-conscious.
• Intellectual Growth: Brain has high learning capacity.
• Emotional Adjustment: Some may feel insecure but these changes are normal.

Fun Fact

• Glands: Sweat, oil, and salivary glands use ducts to release secretions.
• Endocrine Glands: Release hormones directly into the bloodstream (no ducts).

Secondary Sexual Characters

• Reproductive Organs: Testes (boys) and ovaries (girls) produce sperms and ova (eggs).
• Girls: Development of breasts at puberty.
• Boys: Growth of facial hair (moustaches and beard) and chest hair.
• Both Boys and Girls: Growth of hair under arms and in the pubic region.
• Hormones:
  • Testosterone (Boys): Released by testes, causes growth of facial and body hair.
  • Estrogen (Girls): Released by ovaries, causes breast development and growth of mammary glands.
  • Control: Pituitary gland controls the release of sex hormones.

Role of Hormones in Initiating Reproductive Function

• Endocrine Glands: Release hormones into the bloodstream to reach target sites.
• Sex Hormones:
  • Boys: Testosterone causes male secondary sexual characteristics.
  • Girls: Estrogen causes female secondary sexual characteristics.
• Pituitary Gland: Controls the release of hormones that cause maturation of ova and production of sperms.

Reproductive Phase of Life in Humans

• Puberty: Marks the beginning of the reproductive period.
• Males: Reproductive capability lasts much longer.
• Females:
  • Start: Reproductive phase begins around 10 to 12 years of age.
  • Duration: Lasts until about 45 to 50 years.
  • Menstrual Cycle: Occurs every 28 to 30 days, starting with menarche (first menstrual flow) and ending with menopause (stoppage of menstruation).
  • Menstruation: Shedding of the uterine lining if fertilization does not occur.
  • Controlled by Hormones: The cycle includes egg maturation, release, thickening of uterine wall, and its breakdown if pregnancy does not occur.

Key Terms

• Menarche: First menstrual flow at puberty.
• Menopause: Stoppage of the menstrual cycle around 45 to 50 years of age.

Additional Points

• Menstrual Cycle Irregularity: Initially irregular but becomes regular over time.
• Fertilization: If the egg is fertilized, it embeds in the uterus for development.

How is the Sex of the Baby Determined?

Boy or Girl?

• Inside the Zygote: Instructions for determining the sex are in chromosomes.
• Chromosomes:
  • Human cells have 23 pairs of chromosomes.
  • Two of these are sex chromosomes (X and Y).
  • Females: Two X chromosomes.
  • Males: One X and one Y chromosome.
• Gametes:
  • Eggs always have one X chromosome.
  • Sperms can have either one X or one Y chromosome.
• Fertilization:
  • X-carrying sperm + X egg = Female (XX).
  • Y-carrying sperm + X egg = Male (XY).
• Conclusion: The father’s chromosomes determine the baby’s sex (BOY OR GIRL).

Hormones other than Sex Hormones

• Pituitary Gland: Stimulates testes and ovaries, and also controls other endocrine glands.
• Other Endocrine Glands:
  • Thyroid: Produces thyroxine; lack of thyroxine causes goitre.
  • Pancreas: Produces insulin; lack of insulin causes diabetes.
  • Adrenals: Maintain salt balance and produce adrenalin for stress response.
• Hormone Control: Thyroid and adrenals act on orders from the pituitary. The pituitary also secretes growth hormone necessary for normal growth.

Role of Hormones in Completing the Life History of Insects and Frogs

• Metamorphosis:
  • Insects: Controlled by insect hormones.
  • Frogs: Controlled by thyroxine from the thyroid gland.
  • Thyroxine Production: Needs iodine; without iodine, tadpoles can’t become adult frogs.

Key Points

• Endocrine Glands: Important for growth, metabolism, and stress response.
• Metamorphosis: Hormone-driven change in insects and frogs.

Reproductive Health

Importance of Health

• Health: Physical and mental well-being.
• Needs: Balanced diet, personal hygiene, physical exercise.
• Adolescence: Critical time for maintaining health as the body is growing.

Nutritional Needs of Adolescents

• Rapid Growth: Requires a well-planned diet.
• Balanced Diet: Includes proteins, carbohydrates, fats, vitamins.
• Examples:
  • Indian meal (roti/rice, dal, vegetables).
  • Milk and fruits are nutritious.
  • Iron-rich foods (leafy vegetables, jaggery, meat, amla) are essential.
• Avoid: Chips and tinned snacks; they lack nutritional value.

Personal Hygiene

• Bathing: At least once daily.
• Cleanliness: Essential to avoid bacterial infections.
• Menstrual Hygiene:
  • Use sanitary napkins or clean homemade pads.
  • Change pads every 4-5 hours.

Physical Exercise

• Benefits: Keeps the body fit and healthy.
• Activities: Walking, playing outdoor games, exercising.

Myths, Taboos, Do’s, and Don’ts

• Common Myths:
  • A girl becomes pregnant if she looks at boys during menstruation.
  • The mother is responsible for the sex of her child.
  • A girl should not work in the kitchen during menstruation.
• Truth: These are myths and not facts.

Adolescent Pregnancy

• Legal Age for Marriage: 18 for girls, 21 for boys.
• Risks: Early marriage and motherhood cause health problems and limit opportunities.

Say “NO” to Drugs

• Addiction: Drugs are addictive and harmful.
• Health Impact: Ruin health and happiness.
• AIDS Awareness:
  • Caused by HIV, transmitted through shared syringes, infected mother’s milk, and sexual contact.

By following these guidelines, adolescents can ensure their physical and mental well-being during this critical growth period.

Chapter Summary:

• Humans become capable of reproduction after puberty.
• Children between 11 and 19 years are called adolescents.
• Puberty brings growth of reproductive organs.
• Hair grows in various places on the body.
• Girls develop breasts.
• Boys develop facial hair (moustache and beard).
• Boys’ voices become hoarse as the voice box enlarges.
• Children gain height during adolescence.
• Puberty and maturity of reproductive parts are controlled by hormones.
• Hormones are secretions of endocrine glands released into the bloodstream.
• The pituitary gland secretes growth hormones and hormones that stimulate other glands.
• Testes, ovaries, thyroid, and adrenals secrete hormones.
• Pancreas secretes insulin, thyroid produces thyroxine, and adrenals produce adrenalin.
• Testosterone is the male hormone; estrogen is the female hormone.
• The uterine wall in females prepares for a fertilized egg.
• If no fertilization occurs, the uterine lining breaks down and exits the body with blood (menstruation).
• The sex of an unborn child depends on XX or XY chromosomes in the zygote.
• It is important to eat balanced food and maintain personal hygiene during adolescence.

KEYWORDS

1. ADAM’S APPLE
2. ADOLESCENCE
3. ADRENALIN
4. BALANCED DIET
5. ENDOCRINE GLANDS
6. ESTROGEN
7. HORMONES
8. INSULIN
9. LARYNX
10. PITUITARY GLAND
11. PUBERTY
12. REPRODUCTIVE HEALTH
13. SECONDARY SEXUAL CHARACTERS
14. SEX CHROMOSOMES
15. TARGET SITE
16. TESTOSTERONE
17. THYROXINE
18. VOICE BOX