Unit 20: Reaching the Age of Adolescence NMMS SAT 8th

 Here is a comprehensive study note guide for Unit 20: Reaching the Age of Adolescence, NMMS and TNPSC exam preparation. These notes cover all physiological changes, hormonal roles, reproductive phases, and nutritional needs mentioned in the text.

Unit 20: Reaching the Age of Adolescence

I. Introduction to Adolescence

  • Definition: Adolescence is the period of transition from childhood to adulthood. It is the most crucial period in an individual's life.

  • Etymology: The term is derived from the Latin word 'adolescere' meaning 'to grow' or 'grow to maturity'.

  • Duration: This period typically starts at age 13 and ends at age 19 (commonly known as teenage).

  • Biologically: It is marked by the onset of puberty and the termination of physical growth.

II. Puberty

  • Definition: Puberty is a period of rapid physical, physiological, and psychological changes resulting in sexual maturity.

  • Average Age of Onset:

    • Girls: 10–11 years.

    • Boys: 12–13 years.

  • Factors Influencing Puberty: Genetic/biological influences, life events, socio-economic status, nutrition, diet, and body fat amount.

III. Body Changes at Puberty

Four important changes transform a child's body into an adult's:

1. Changes in Body Size (Growth)

  • Height: Sudden increase in height. Both boys and girls add around 23 cm to 26 cm in height during adolescence.

  • Weight: Significant increase. Average weight gain is about 17 kg to 19 kg.

    • Girls: Increase in fat.

    • Boys: Muscle development.

2. Changes in Body Proportion

  • Limbs: Feet and hands grow disproportionately big.

  • Trunk: Lengthens and broadens at the hip and shoulder to give the adult proportion.

3. Primary Sex Characteristics

  • Functionality: Reproductive organs become fully functional.

  • Males: Testes grow larger; reproductive organ increases in length and size. Testes are the primary male sex organs.

  • Females: Ovaries and uterus increase in size/weight. Ovaries are the primary female sex organs.

4. Secondary Sex Characteristics

These are physical features distinguishing males from females.

Boys:

  • Hair: Pubic hair appears first, followed by axillary (armpit) and facial hair.

  • Skin: Becomes coarse; pores enlarge. Oil glands enlarge, causing acne.

  • Muscle: Strength increases; arms, legs, and shoulders shape up.

  • Voice: Becomes husky, pitch drops, volume increases.

    • Adam’s Apple: The protruding part of the throat caused by the growth of the larynx (larger in boys than girls).

    • Mechanism: Male hormones loosen and thicken the chords attached to the cartilage, producing a hoarse sound.

Girls:

  • Hips: Pelvic bone enlarges and subcutaneous fat develops, making hips wider and rounder.

  • Breast: Breasts begin to develop.

  • Hair: Pubic hair appears, followed by axillary and body hair.

  • Voice: Becomes shrill (high-pitched); voice breaks are rare.

  • Skin/Glands: Skin becomes coarser; oil glands become active causing acne.

IV. Role of Hormones in Reproduction

Hormones are chemical substances secreted by endocrine glands (ductless glands) directly into the bloodstream.

1. Regulation:

  • Reproduction is regulated by the Anterior Pituitary gland.

  • Key regulatory hormones: FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone).

2. Male Hormones:

  • Testosterone (Androgen): Secreted by the testes.

    • Stimulated by LH (also called ICSH - Interstitial Cell Stimulating Hormone in males).

    • Functions: Growth of larynx, muscle development, skeletal size, body/pubic hair, sweat glands.

  • FSH in Males: Necessary for spermatogenesis (sperm production) and development of seminiferous tubules.

3. Female Hormones:

  • Estrogen: Secreted by the ovaries.

    • Stimulated by FSH (development of Graafian follicle).

    • Functions: Development of breast, external genitalia, pubic/axillary hair, body fat distribution.

  • Progesterone: A gestational hormone. Secretion stimulated by LH.

  • LH in Females: Essential for ovulation and final maturation of the Graafian follicle.

4. Other Hormones:

  • Prolactin (Lactogenic Hormone): Milk secretion during lactation.

  • Oxytocin: Expulsion of milk and contraction of uterine muscles during childbirth.

V. Reproductive Phases in Humans

  • Females: Starts at puberty (10–12 years) and ends at menopause (45–50 years).

  • Males: Starts at 13 years and continues lifelong.

Key Phases in Females:

  1. Menarche: The first menstrual flow begins at puberty.

  2. Ovulation: The release of a mature ovum from the ovary. Occurs once in about 28 to 30 days (approx. day 14 of the cycle).

  3. Pregnancy: If the ovum is fertilized, it implants in the uterus. The corpus luteum produces progesterone to maintain pregnancy. Normally lasts 280 days.

  4. Menstruation: If fertilization does not occur, the corpus luteum degenerates, hormone levels drop, and the uterine lining sheds. Bleeding lasts 3 to 5 days.

  5. Menopause: Stoppage of menstruation around 45 to 50 years of age. Symptoms include anxiety, irritability, and fatigue.

Menstrual Cycle:

  • Marks the onset of puberty.

  • Repeats every 28 days.

  • Controlled by hormones.

  • Stops temporarily during pregnancy and restarts after childbirth.

VI. Nutritional Needs of Adolescents

Adolescence requires a balanced diet due to rapid growth.

  • Balanced Diet: Proteins, carbohydrates, fats, and vitamins in requisite proportions. Indian meal (roti/rice, dal, milk, vegetables) is good.

  • Minerals Needed:

    • Calcium: For skeletal mass. Found in milk/milk products. Prevents osteoporosis.

    • Iodine: Prevents thyroid diseases.

    • Iron: Builds blood. Prevents anemia.

      • Iron-rich foods: Green leafy vegetables, jaggery, meat, dates, fish, citrus, Indian gooseberry (Nelli).

      • Importance: Boys need it for muscle spurt; Girls need it for menstruation loss.

VII. Reproductive Health & Hygiene

  • Definition (WHO): Total well-being of behavioural, emotional, physical, and social aspects.

  • Sleep: Adolescents need 8 to 10 hours of sleep.

  • Cleanliness: Daily bath, changing undergarments daily (cotton is preferred).

  • Menstrual Hygiene: Use disposable napkins/tampons. Change frequently. Avoid repeated use of cloth unless washed with hot water and dried in sunlight.

  • Physical Exercise: Promotes sound sleep and mental peace.

VIII. Important Exam Key Points

  • Adam's Apple: Protruding voice box in boys.

  • Testosterone: Male hormone (Testes).

  • Estrogen: Female hormone (Ovaries).

  • Menarche: First menstruation.

  • Menopause: Stoppage of menstruation (45-50 years).

  • Ovulation: Release of egg (Day 14).

  • Iron: Essential to prevent anemia; found in green veggies and jaggery.

  • Sebaceous glands: Oil glands responsible for acne/pimples during puberty.


Here are 50 multiple-choice questions (MCQs) based on Unit 20: Reaching the Age of Adolescence, designed for your NMMS and TNPSC exam preparation.

Topic: Adolescence and Puberty

1. The term "Adolescence" is derived from the Latin word 'adolescere' which means:

a) To reproduce

b) To grow to maturity

c) To change voice

d) To become strong

Answer: b) To grow to maturity

2. Adolescence typically begins at the age of:

a) 10

b) 11

c) 13

d) 15

Answer: c) 13

3. The period of adolescence usually ends at the age of:

a) 18

b) 19

c) 21

d) 25

Answer: b) 19

4. The average age for the onset of puberty in girls is:

a) 12-13

b) 10-11

c) 14-15

d) 8-9

Answer: b) 10-11

5. During adolescence, both boys and girls add approximately how much to their height?

a) 10 cm to 15 cm

b) 15 cm to 20 cm

c) 23 cm to 26 cm

d) 30 cm to 35 cm

Answer: c) 23 cm to 26 cm

6. The average weight gain during the adolescent period is:

a) 5-10 kg

b) 10-12 kg

c) 17-19 kg

d) 20-25 kg

Answer: c) 17-19 kg

7. In boys, the primary sex organs are the:

a) Ovaries

b) Testes

c) Thyroid

d) Adrenals

Answer: b) Testes

8. Which body part grows disproportionately big during the change in body proportion?

a) Head

b) Stomach

c) Feet and hands

d) Neck

Answer: c) Feet and hands

9. Puberty is marked by the onset of:

a) Emotional maturity

b) Sexual maturity

c) Career choices

d) Aging

Answer: b) Sexual maturity

10. In girls, increase in weight during adolescence is associated with an increase in:

a) Muscle mass

b) Fat

c) Bone density

d) Height only

Answer: b) Fat

Topic: Secondary Sexual Characteristics

11. The protruding part of the throat seen in adolescent boys is called:

a) Thyroid cartilage

b) Voice box

c) Adam's apple

d) Epiglottis

Answer: c) Adam's apple

12. The Adam's apple is formed due to the growth of the:

a) Pharynx

b) Larynx

c) Oesophagus

d) Tongue

Answer: b) Larynx

13. Acne and pimples in adolescents are caused by the increased activity of:

a) Sweat glands

b) Salivary glands

c) Oil (sebaceous) glands

d) Thyroid glands

Answer: c) Oil (sebaceous) glands

14. Which secondary sexual characteristic is specific to girls?

a) Broadening of shoulders

b) Widening of hips

c) Growth of facial hair

d) Deepening of voice

Answer: b) Widening of hips

15. The male hormone responsible for secondary sexual characteristics is:

a) Estrogen

b) Progesterone

c) Testosterone

d) Oxytocin

Answer: c) Testosterone

16. The female hormone responsible for the development of breasts is:

a) Testosterone

b) Estrogen

c) Androgen

d) Insulin

Answer: b) Estrogen

17. In boys, the voice becomes deep and harsh because the vocal chords:

a) Shorten and thin out

b) Loosen and thicken

c) Disappear

d) Become rigid

Answer: b) Loosen and thicken

18. Voice breaks are rare among:

a) Boys

b) Girls

c) Infants

d) Adults

Answer: b) Girls

19. Androgens stimulate the stimulation of which glands?

a) Tear glands

b) Sweat glands

c) Salivary glands

d) Pituitary glands

Answer: b) Sweat glands

20. Which hormone regulates the secondary sex characters in males?

a) Estrogen

b) Androgen

c) Progesterone

d) Prolactin

Answer: b) Androgen

Topic: Role of Hormones

21. Hormones are secreted by which type of glands?

a) Exocrine glands

b) Endocrine glands

c) Duct glands

d) Salivary glands

Answer: b) Endocrine glands

22. Which gland regulates the secretion of hormones from gonads?

a) Thyroid

b) Adrenal

c) Anterior Pituitary

d) Pancreas

Answer: c) Anterior Pituitary

23. LH stands for:

a) Lactogenic Hormone

b) Luteinizing Hormone

c) Long Hormone

d) Lipid Hormone

Answer: b) Luteinizing Hormone

24. In males, LH stimulates the testes to produce:

a) Estrogen

b) Androgens

c) Progesterone

d) Insulin

Answer: b) Androgens

25. FSH stands for:

a) Female Sex Hormone

b) Follicle Stimulating Hormone

c) Fat Stimulating Hormone

d) Fertilization Start Hormone

Answer: b) Follicle Stimulating Hormone

26. Which hormone is necessary for spermatogenesis in males?

a) LH

b) FSH

c) Prolactin

d) Oxytocin

Answer: b) FSH

27. The hormone responsible for milk secretion during lactation is:

a) Estrogen

b) Prolactin

c) Oxytocin

d) Progesterone

Answer: b) Prolactin

28. Which hormone causes the expulsion of milk from the breast?

a) Prolactin

b) Oxytocin

c) FSH

d) LH

Answer: b) Oxytocin

29. In males, LH is also referred to as:

a) FSH

b) ICSH

c) TSH

d) ACTH

Answer: b) ICSH

30. Which hormone is necessary for ovulation in females?

a) FSH

b) LH

c) Testosterone

d) Insulin

Answer: b) LH

Topic: Reproductive Phases

31. The first menstrual flow that begins at puberty is called:

a) Menopause

b) Menarche

c) Ovulation

d) Pregnancy

Answer: b) Menarche

32. Ovulation usually occurs on which day of a 28-day cycle?

a) Day 1

b) Day 5

c) Day 14

d) Day 28

Answer: c) Day 14

33. The release of an ovum from the ovary is called:

a) Fertilization

b) Menstruation

c) Ovulation

d) Implantation

Answer: c) Ovulation

34. If fertilization occurs, the corpus luteum produces large amounts of:

a) Estrogen

b) Progesterone

c) LH

d) FSH

Answer: b) Progesterone

35. Normal pregnancy lasts for how many days?

a) 250 days

b) 280 days

c) 300 days

d) 365 days

Answer: b) 280 days

36. The shedding of the uterine lining along with blood is called:

a) Ovulation

b) Fertilization

c) Menstruation

d) Menopause

Answer: c) Menstruation

37. Menstruation typically lasts for:

a) 1-2 days

b) 3-5 days

c) 10-12 days

d) 14 days

Answer: b) 3-5 days

38. Stoppage of menstruation is termed as:

a) Menarche

b) Menopause

c) Pause

d) Maturity

Answer: b) Menopause

39. Menopause usually occurs at the age of:

a) 30-35 years

b) 45-50 years

c) 60-65 years

d) 70-75 years

Answer: b) 45-50 years

40. Menstruation stops temporarily during:

a) Puberty

b) Pregnancy

c) Sleep

d) Exercise

Answer: b) Pregnancy

Topic: Nutritional Needs & Health

41. Which mineral is essential to prevent osteoporosis in later life?

a) Iron

b) Iodine

c) Calcium

d) Zinc

Answer: c) Calcium

42. Which mineral helps to prevent thyroid gland-related diseases?

a) Iron

b) Calcium

c) Iodine

d) Phosphorus

Answer: c) Iodine

43. Iron is essential for building:

a) Bones

b) Blood

c) Teeth

d) Muscles

Answer: b) Blood

44. Which of the following is an iron-rich food?

a) Milk

b) Jaggery

c) Rice

d) Cheese

Answer: b) Jaggery

45. Lack of iron in the diet results in:

a) Goiter

b) Anemia

c) Rickets

d) Scurvy

Answer: b) Anemia

46. How many hours of sleep each night is necessary for adolescents?

a) 5 to 6 hours

b) 6 to 8 hours

c) 8 to 10 hours

d) 10 to 12 hours

Answer: c) 8 to 10 hours

47. Women need to take more iron to make up for the loss of blood during:

a) Urination

b) Perspiration

c) Menstruation

d) Digestion

Answer: c) Menstruation

48. Ideally, undergarments should be made of:

a) Silk

b) Nylon

c) Cotton

d) Wool

Answer: c) Cotton

49. Which of the following can induce menopause artificially?

a) Eating junk food

b) Surgical removal of ovaries

c) Lack of sleep

d) Excessive exercise

Answer: b) Surgical removal of ovaries

50. During adolescence, nutritional deficiencies can delay:

a) Height growth only

b) Weight gain only

c) Sexual maturation

d) Hair growth

Answer: c) Sexual maturation

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