Reaching The Age Of Adoloscence Online Test 8th Science Lesson 14 Questions in English

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Growing up is a natural process that takes place in all living organisms. All living organisms grow up to maturity which is the ability to respond to a particular environment. Maturity along with experiences produces a progressive series of changes in an organism. These series of changes are called development.

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Different phases of human development are called developmental stages. Human developmental stages include infancy, childhood, adolescence, adulthood, middle age and old age.

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Among all these stages, adolescence is the most crucial and significant period in an individual’s life. It is the period of transition from childhood to adulthood.

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The period of adolescence starts at the age of about 10 to 13 and ends at the age of 19 (commonly known as teenage).

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The term adolescence is derived from the Latin word ‘adolescere’ meaning ‘to grow’ or ‘grow to maturity’.

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During this period changes occur in height, weight, sex organs, muscle mass as well as in brain structure and function.

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Biologically it is a physical transition marked by the onset of puberty and termination of physical growth in an individual.

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Puberty is a period of few years in which rapid physical; physiological and psychological changes occur resulting in sexual maturity. We can predict the sequence of physical changes that will take place but the age of beginning of puberty varies from individual to individual.

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The average age for the onset of puberty is 10 or 11 for girls and 12 or 13 for boys. But, factors like genetic and biological influences, life events, socioeconomic status, nutrition and diet and the amount of body fat also affect the onset and progression of puberty.

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Hormones play an important role at the time of puberty. Changes in hormones during this period trigger physical and behavioral changes. Sex hormones secreted at the time of puberty activate the male and female sex glands to produce necessary secretions in the body.

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The male sex glands, testes release the testosterone and the female sex gland the ovaries release the estrogen in puberty period. These result in changes in the primary and secondary sexual characteristics of the male and female.

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Four important changes that occur during puberty transform the body of a child into that of an adult. These changes are: Changes in body size, Changes in body proportion, Development of primary sex characteristics, and Development of secondary sex characteristics.

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The first major change at the time of puberty is growth which is the increase in body height and weight.

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The physical growth usually begins at the age of 10 to 12 in girls and 12 to 13 in boys. It is almost complete at around 17 to 19 in girls and 19 to 20 in boys. During adolescence both boys and girls add around 23 cm to 26 cm in the height.

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In addition to height, they also experience significant increase in weight. But increase in weight is influenced by various factors like diet, exercise and life style. The average weight gain during this period is about 17 kg to 19 kg. During this period, increase in fat is seen in girls in contrast to muscle development in boys.

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Certain body areas which are small proportionately grow big. This can be seen in feet and hands. During childhood, legs grow proportionately more than the trunk. But at the time of puberty trunk also lengthens. Also, trunk broadens at the hip and shoulder thus giving the adult proportion to the body.

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Reproductive organs of boys and girls become fully functional at the time of puberty. In boys, testes grow larger followed by that length and size of the reproductive organ increase. Similarly, female reproductive organ also grows during puberty. Thus, the size of the uterus and the weight of the ovaries increase during this time.

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Testes and ovaries are called primary sex organs of the male and female respectively.

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Secondary sex characteristics are the physical features which distinguish male from female. After the progression of puberty, boys and girls become dissimilar in appearance. The secondary sex characters are regulated by the hormones the testosterone or androgen secreted by the testes of the males and estrogen secreted by the ovaries of the females.

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Androgens cause the growth of the larynx, muscle development, skeletal size and distribution of body and pubic hair, and stimulation of sweat glands.

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Estrogen and progesterone are the female sex hormones. Estrogen stimulates the development of the breast, the external genitalia, pubic and axillary hairs, and the distribution of body fat.

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The following are the secondary sex characteristics of boys.

Hair: Immediately after the development of primary sex characteristics, pubic hair appears followed by axillary and facial hair.

Skin: The skin becomes coarse and the pores in the skin enlarge.

Glands: The oil producing glands in the skin enlarge and due to this acne may appear on the faces.

Muscle: The strength of the muscle increases and it gives shape to arms, legs and shoulders.

Voice: During this period voice changes occur and the voice becomes husky. Then its pitch drops and the volume increases.

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The secretions of sweat and sebaceous or subcutaneous glands (Oil glands) are very active during adolescence. Many adolescent boys and girls get pimples on face because of increased activity of these glands in the skin. Owing to extra secretions sometimes a distinctive odor is also produced from the bodies.

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At puberty, the growth of the larynx is larger in boys than that of girls. The growing voice box in boys can be seen as a protruding part of the throat called Adam’s apple, so that the voice becomes deep and harsh. This is caused mainly by male hormone (regulatory chemicals) during adolescence. As a result of this, muscles (chords) attached to the cartilage get loosened and thickened. When air passes through these loosened and thickened chords a hoarse sound is produced. In girls larynx is hardly visible from outside because of its small size and the voice becomes high pitched.

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The primary hormones that regulate reproduction are the steroids such as androgens, estrogens and progesterone which have masculinizing, feminizing and gestational effects respectively. These hormones are secreted from the glands which are regulated by the anterior pituitary (adenohypophysis).

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In male and female, reproductive behavior and reproduction are mainly under the control of LH (Luteinizing Hormone) and FSH (Follicle Stimulating Hormone). LH stimulates the testes to produce androgens, the male sex hormone. Sperms are then actively produced. In man sperm production starts at sexual puberty and may continue throughout his life.

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Follicle Stimulating Hormone (FSH): FSH in the female influences the development of the Graafian follicle and secretion of estrogens. In the male it is necessary for the development of seminiferous tubules, and for spermatogenesis.

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Luteinizing Hormone (LH): In the female, it is the hormone necessary for ovulation, and the secretion of the luteal hormone progesterone, and for the final maturation of the Graafian follicle. Estrogen is not a single hormone but a collection of related steroid hormones.

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In the male the Luteinizing Hormone stimulates the interstitial (Leydig) cells of testes and the secretion of testosterone, and is referred to as the Interstitial Cell Stimulating Hormone (ICSH).

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Prolactin (PRL) or Lactogenic Hormone: The main function of this hormone is milk secretion during lactation.

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Oxytocin Hormone: Oxytocin causes expulsion of milk from the breast and it is also involved in the contraction of smooth muscles of uterus during child birth.

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Reproduction is more important for the continuation of human race. The phase in an individual’s life during which there is production of gametes is called reproductive phase.

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In females, the reproductive phase of life begins at puberty (10 to 12 years of age) and generally lasts till the age of approximately 45 to 50 years, and in males, it is from the age of 13 to life long. The reproductive age may vary from person to person.

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The following are the reproductive phases in the life of a female. Menarche, Ovulation and Pregnancy.

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The first menstrual flow begins at puberty and is termed menarche. The ova begin to mature with the onset of puberty. It is the beginning of adolescence, during which mental and emotional maturation occurs and physical growth becomes pronounced.

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Menstruation: If the ovum is not fertilized the corpus luteum begins to degenerate and the production of hormones progesterone and estrogen ceases. The unfertilized egg and the thickened lining of the uterus along with its blood vessels are shed off. This causes bleeding in woman’s reproductive tract which is called menstruation.

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Menopause: Menopause marks the end of the reproductive phase of a woman’s life. At 45 to 50 years of age, the menstrual cycle stops. Stoppage of menstruation is termed as ‘menopause’.

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During menopause psychological symptoms such as anxiety, irritability, fatigue and loss of concentration may occur. Menopause may be induced by surgical removal of the ovaries, or by pelvic irradiation in a woman of any age.

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Usually one mature ovum (or egg) is released from one of the ovaries into the oviduct once in every 28 days. This is called ovulation.

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Menstruation usually occurs 14 days after ovulation and usually lasts for about 3 to 5 days.

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The cycle of menstruation is repeated again and again in women after every 28 days. The menstrual cycle is controlled by hormones.

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Menstruation stops temporarily when the ovum gets fertilized and the women get pregnant. This is because, in this case the thick and soft lining of the uterus containing lot of blood vessels is needed for the growth and development of the fertilized ovum to form a baby. Menstruation restarts after the birth of the baby. Menstruation also stops due to nutritional deficiencies, low body weight, stress, eating disorder, excessive weight gain etc.

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The physical and mental well-being of an individual is regarded as an individual’s health. The World Health Organization (WHO) has defined the reproductive health as the total well-being of behavioral, emotional, physical and social aspects of adolescence. To keep the body healthy, every human being at any age, needs to have a diet, exercise and personal hygiene.

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The following are some of the measures that girls and boys need to take. Cleanliness, Physical exercise, Personal hygiene, Balanced diet.

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Physical Exercise: Walking and playing in fresh air keeps the body fit and healthy. All young boys and girls should take a walk, exercise and play outdoor games. Physical activity leads to the conditions of better health, sound sleep and thereby mental peace. Mental peace promotes happiness in day to day existence.

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Adolescence is a stage of rapid growth and development. Hence a diet with proper calories and other nutrients is needed for proper growth and physical activity.

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Balanced diet is very much important during adolescence. Balanced diet includes proteins, carbohydrates, fats and vitamins in requisite proportions. Our Indian meal of roti / rice, dal (pulses), milk, fruits and vegetables forms a balanced food.

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The nutritional deficiencies during this period not only retard the physical growth but also impair the intellectual development and may also delay sexual maturation. A very good amount of proteins and carbohydrates is necessary during this growth period.

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Since there is an increase in skeletal mass and blood volume during adolescence, the body needs calcium, phosphorus and iron.

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Calcium: Calcium intake needs to be increased to prevent osteoporosis in later life. It is present in milk and milk products or other equivalents.

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Iodine: It helps to prevent thyroid gland related diseases.

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Iron: Iron builds blood and iron-rich foods such as green leafy vegetables, jaggery, meat, dates, fish, chicken, citrus, Indian gooseberry (Nelli) and whole pulses are good for adolescents. Lack of iron in the diet results in anemia. To make up for the loss of iron, adolescents need to have a diet rich in iron. In boys, iron deficiency occurs due to muscle spurt whereas in girls it occurs due to menstruation in addition to the muscular growth. Women should take in more iron in their diet regularly to make up for the loss of blood during menstruation.

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During adolescence, growing children need special attention towards diet, exercise and personal hygiene.

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Personal hygiene is a clear indicator of man’s personality. Personal hygiene starts from the hair tip and ends down at the toes. Personal hygiene habits for the adolescence are as follows. Shower or bath daily. Always wash your hands before and after meals. Keep fingernails clean and dipped. Wash your teeth and mouth before and after each meal. Avoid touching your face, nose or mouth while preparing food. Avoid coughing or sneezing around food and close your mouth by using hand kerchief while you cough in public places. If you want to taste the food, use a clean spoon. Change your clothes regularly and wash them cleanly, especially undergarments. Do not defecate in open field. Use clean toilets for defecation. If you are not well, avoid self-medication consult a doctor.