Reaching the Age of Adolescence

Reaching the Age of Adolescence

• The chapter discusses the changes in the human body that lead to reproductive capability.
• Chapter 6 covered human reproductive organs.
• This chapter focuses on the role of hormones in these changes.

Adolescence and Puberty

• Adolescence is the period of life when the body undergoes changes leading to reproductive maturity.
• Adolescence starts around age 11 and lasts until 18 or 19.
• Adolescents are also called 'teenagers' since the period covers the 'teens' (13 to 18 or 19 years of age).
• Adolescence for girls may begin a year or two earlier than for boys.
• The period of adolescence is unique for each person.
• Several changes occur in the human body during adolescence, marking the onset of puberty.
• The most important change at puberty is that boys and girls become capable of reproduction.
• Puberty ends when an adolescent reaches reproductive maturity.

Changes at Puberty

• The most noticeable change during puberty is the sudden increase in height.
• During this time, the long bones of the arms and legs elongate, making a person taller.

Increase in Height

• By age 11, a boy reaches 81% of his probable full height, while a girl reaches 88% of her full height.
• These figures are representative and individual variations occur.
• Initially, girls grow faster than boys but by age 18, both reach their maximum height.
• The rate of height growth varies among individuals, with some growing suddenly and then slowing down, while others grow gradually.
• All body parts do not grow at the same rate; arms, legs, hands, and feet might seem oversized initially.
• Height is influenced by genes inherited from parents.
• Proper nutrition is crucial for bone, muscle, and body part development during these growing years.

Change in Body Shape

• Boys develop broader shoulders and wider chests during puberty, while girls develop a wider region below the waist.
• Muscles grow more prominently in boys compared to girls.
• Changes differ between adolescent boys and girls.

Voice Change

• At puberty, the voice box, or larynx, begins to grow, resulting in voice cracking in some boys.
• Boys develop larger voice boxes, which can be seen as a protruding part of the throat called the Adam's apple.
• Girls have a hardly visible larynx due to its small size, generally having a high-pitched voice.
• Adolescent boys may experience temporary voice hoarseness as the muscles of the growing voice box go out of control.

Increased Activity of Sweat and Sebaceous Glands

• During puberty, the secretion of sweat glands and oil glands increases, leading to acne and pimples due to increased gland activity in the skin.
• Sweat, oil, and salivary glands release secretions through ducts.
• Endocrine glands release hormones directly into the bloodstream, and are termed ductless glands.

Development of Sex Organs

• At puberty, male sex organs (testes and penis) develop completely, and the testes begin to produce sperms.
• In girls, the ovaries enlarge, eggs begin to mature, and ovaries start releasing mature eggs.

Reaching Mental, Intellectual, and Emotional Maturity

• Adolescence involves changes in a person's way of thinking, leading to more independence and self-consciousness.
• Intellectual development occurs, with adolescents spending more time thinking and developing an increased capacity for learning.
• Adolescents may feel insecure while adjusting to bodily and mental changes.

Secondary Sexual Characteristics

• Boys grow facial hair and develop hair on their chest.
• Hair grows under the arms and in the pubic region for both boys and girls
• These features distinguishing males from females are called secondary sexual characteristics.

Role of Hormones in Initiating Reproductive Function

• Changes during adolescence are controlled by hormones, which are chemical substances secreted by endocrine glands
• In males, the testes release testosterone, leading to changes like facial hair growth.
• In females, the ovaries produce estrogen, causing breast development. Milk-secreting mammary glands develop inside the breasts.
• The pituitary gland controls the production of these hormones.
• Endocrine glands release hormones into the bloodstream to reach a specific target site, which then responds to the hormome.

Reproductive Phase of Life in Humans

• Adolescents become capable of reproduction when their testes and ovaries start producing gametes, with males having a longer capacity for gamete production than females.
• In females, the reproductive phase starts at puberty (10-12 years) and lasts until approximately 45-50 years, with ova maturing at puberty.
• One ovum matures and is released by an ovary every 28-30 days.
• The uterus wall thickens to receive the egg.
• If fertilization occurs, pregnancy results; if not, the egg and uterine lining are shed, causing menstruation.
• Menstruation occurs every 28-30 days, with the first menstrual flow termed menarche.
• Menopause is the stoppage of the menstrual cycle around 45-50 years of age.
• Menstrual cycles may be irregular initially.
• The menstrual cycle is controlled by hormones and includes egg maturation, release, thickening of the uterine wall, and its breakdown if pregnancy doesn't occur.

How is the Sex of the Baby Determined?

• The sex of the baby is determined by instructions present in chromosomes inside the fertilized egg.
• Human beings have 23 pairs of chromosomes, with two being sex chromosomes (X and Y).
• Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
• Gametes have one set of chromosomes; eggs always have one X chromosome, while sperms have either an X or a Y chromosome.
• If a sperm with an X chromosome fertilizes the egg, the zygote will have XX chromosomes, resulting in a female child.
• If a sperm with a Y chromosome fertilizes the egg, the zygote will have XY chromosomes, resulting in a male child.
• The father's sex chromosomes determine the sex of the unborn baby.

Hormones Other Than Sex Hormones

• Pituitary hormones stimulate testes and ovaries to produce their hormones.
• The pituitary gland, an endocrine gland attached to the brain, also has testes and ovaries.
• Other endocrine glands include the thyroid, pancreas, and adrenals.
• The pituitary gland stimulates testes to produce hormones.
• Goitre, a disease of the thyroid gland, is caused by the thyroid gland not producing thyroxine.
• The pancreas produces insulin, while adrenal glands secrete hormones to maintain salt balance in the blood and produce adrenalin to help the body adjust to stress.
• The pituitary gland also secretes growth hormone for normal growth.

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

• The change from larva to adult is called metamorphosis.
• In frogs, metamorphosis is controlled by thyroxine, which requires iodine in water to produce. If there is insufficient iodine, tadpoles will not become adults.

Reproductive Health

• Physical and mental well being is regarded as health.
• A balanced diet, personal hygiene, and adequate physical exercise are needed to keep the body healthy at any age. These are all essential during adolescence.
• Adolescence is a stage of rapid growth and development that requires a carefully planned diet.

Nutritional Needs of the Adolescents

• A balanced diet consists of proteins, carbohydrates, fats, and vitamins in proper portions.
• An Indian meal - roti/rice, dal (pulses), and vegetables makes a balances meal
• Milk, fruits, leafy vegetables, jaggery, meat, citrus fruits, and Indian gooseberry (amla) are good for adolescents.
• Chips, packed, or tinned snacks shouldn't replace regular meals because of their insufficient nutritional value.

Personal Hygiene

• Showering daily is essential, especially for teenagers due to increased sweat gland activity. All body parts should be washed and cleaned every day.
• Girls should take special care during menstruation, track their menstrual cycle, and use sanitary napkins or clean homemade pads, changing them every 4–5 hours.

Physical Exercise

• Walking and playing in fresh air is good for the body, therefore boys and girls should take walks, exercise, and play outdoor games.

Myths, Taboos, Do's, and Don'ts

• There are myths regarding bodily changes experienced by adolescents which should be discarded.
• According to law, the legal age for marriage is 18 for girls and 21 for boys. Teenage mothers are often mentally and physically unprepared for motherhood which can cause health problems and a lack of opportunities.

Say No to Drugs

• Adolescence is a period of much activity in the body and mind which is a normal part of growing up, and as such, one shouldn't feel confused or insecure
• Don't take drugs unless prescribed by a doctor because they are addictive, harmful, and ruin health and happiness.
• The HIV virus, which causes AIDS, can be transmitted through shared needles, from infected mothers to infants through milk, and through sexual contact.