Adolescence and Puberty · 2020-06-25 · Adolescence is the period of life when many changes take place in the body; leading to reproductive maturity. Adolescence begins at around

Adolescence and Puberty

Too often you must have noticed your parents and relatives asking you

to be more responsible because you are an ‘adolescent’ now! What

does that mean? Is it anything more than your age just increasing over

the years? A lot more, to be honest! You must have noticed various

changes in your body and also your voice when you entered your

teenage. Why does all that happen? In this chapter, we will cover

adolescence and puberty. This will help you understand your ‘ageing’

better.

What are adolescence and puberty?

Adolescence is the period of life when many changes take place in the

body; leading to reproductive maturity. Adolescence begins at around

10 years of age and lasts till you are 18 or 19 years of age. The years

during adolescence period are counted as ‘teen’, .e.g. thirteen,

fourteen and fifteen. Hence, this period is also called teenage.

The process of changes during adolescence period is what we call

puberty. Beginning of puberty marks the beginning of adolescence.

The end of adolescence or puberty marks the completion of

reproductive maturity. So, what are the changes that you may notice in

your puberty?

Changes at Puberty

Too often, you can notice very prominent changes in your own body

as well your friends‘. This is all because of puberty.

Source: FuseSchool

● Increase in Height: The most apparent change during puberty is

the sudden increase in height. Long bones grow rapidly. Hence,

the height of a person increases rapidly during this period.

Initially, girls grow faster than boys but ultimately boys are

usually taller than girls. The maximum height is attained by 18

years of age.

● Change in Body Shape: The body of a boy becomes more

muscular. His shoulders become wide and the waist becomes

narrow. The body of a girl becomes wider below waist and

narrower at the shoulder.

● Voice Change: A boy’s voice becomes deep, and the childlike

voice is first replaced by a hoarse voice. This happens because

the voice is said to crack. Gradually, the voice becomes deep.

The change in voice happens because voice box in a boy

becomes larger. Girl’s voice is usually high pitched.

● Increased Activity of Sweat and Sebaceous Glands: Secretion

from sweat and sebaceous glands increases during adolescence.

Due to this, some teenagers may suffer from acne and pimples.

● Development of Sex Organs: In boys, testes begin to produce

sperms. Testis and penis develop completely. In girls, ovaries

enlarge and eggs begin to mature. Ovaries start releasing a

mature egg.

● Reaching Mental, Intellectual and Emotional Maturity: These

changes also have a profound effect on a person’s way of

thinking. Teenagers spend more time on thinking than earlier.

Thus, many rapid changes in the body may create a sense of

insecurity in most of the teenagers. But, teenagers should not

worry because these are natural changes. They will definitely

go away with time.

● Adam’s Apple: Enlargement of voice box is apparent as a

prominent protrusion in the neck. This protrusion is called

Adam’s apple.

Secondary Sexual Characters

Secondary sexual characters help in distinguishing a male from a

female. Sexual dimorphism is the marked difference between male

and female of a species because of apparent physical traits. Some

common secondary sexual characters include:

● Secondary Sexual Characters in Boys: Facial hairs, deep voice

and hair on chest.

● Secondary Sexual Characters in Girls: Enlargement of breasts

and high pitched voice.

● Some common characters in girls and boys: Hair under armpits,

hair in the pubic region.

Hormonal Control

Hormones control these changes in the adolescent period. The

endocrine glands secrete these hormones. Hormones play important

role in various metabolic activities.

● In boys, testis secretes the hormone testosterone. This hormone

is responsible for many changes in boys.

● In girls, ovaries secrete the hormone estrogen. This is

responsible for the development of breasts.

The action of these hormones is under the control of a hormone

secreted by the pituitary gland. Another hormone from pituitary gland

stimulates the maturation of eggs and production of sperms. Endocrine

glands are ductless glands; which means that a hormone reaches the

target site through the bloodstream.

Solved Example

Question: Explain the reproductive phase of life in humans.

Answer: The reproductive phase begins with the onset of puberty and

it happens at around the same age in boys and girls. But, the

reproductive phase in men lasts much longer than in females.

Reproductive phase in women lasts till about 50 years of age.

Reproductive phase in men lasts even beyond 60 years of age.

● Menstruation: In females, the ovaries release one egg during

each month. After that, the uterus develops a thickening to

support a foetus to prepare for a possible pregnancy. If

fertilization does not take place; egg and thickening in the

uterus break in small fragments. This results in bleeding

through the vagina for some days. Menstruation is the bleeding

(through the vagina) at the end of the menstrual cycle.

● Menstrual Cycle: Menstrual cycle refers to the events which

begin with the release of an egg and end in shedding off the

egg. A menstrual cycle is usually of 28 to 30 days.

● Menarche: The first menstrual bleeding in a girl’s life is called

menarche. Menarche marks the beginning of puberty in girls.

● Menopause: Menopause is the cessation of the menstrual cycle.

This happens at around 45 – 50 years of age. Menopause marks

the end of the reproductive phase.

Functions of Endocrine Gland

How many of you experience various hormonal changes? Almost all

of us! Isn’t it? But, why do these changes happen? Who secretes these

hormones? In this chapter, we will look at the Functions of Endocrine

Gland, the hormones they secrete and so on.

Endocrine System

Before we proceed with the topic, do you know who the mastermind

behind these hormones is? Let us first see that. Yes! The endocrine

system is the main system to control all the development of hormones

in our body. The endocrine system is comprised of nine primary

glands. These glands produce hormones. There are many other organs

that provide secondary functions such as processing the secretions to

trigger bodily function of endocrine gland.

Endocrine Glands

So, what are endocrine glands? Endocrine glands are important glands

of the endocrine system. They secrete their products, hormones,

directly into the blood rather than through a duct. The endocrine

glands belong to the body’s control system. The hormones which they

produce help to regulate the functions of both cells and tissues

throughout the body. the various types of major endocrine glands

include:

● Pituitary gland (Hypophysis)

● Thyroid gland

● Parathyroid glands

● Adrenal glands

● Pancreas

● Gonads

● Pineal gland

These glands produce different types of hormones. These hormones

induce a different and a specific response in other cells, tissues, and

also the organs that are located throughout the body. We will now

look at each of these glands in brief and understand their primary

functions.

Pituitary gland (Hypophysis)

The pituitary gland hangs from the base of the brain by a stalk. It is

enclosed and also protected by a bone. It consists of a

hormone-producing glandular portion and a neural portion.

The pituitary gland is the master gland. This is pea-sized and is

located at the bottom of the brain. They control and regulate other

glands in the body. Hormones released by this gland are growth

hormone, thyroid stimulating hormone, Luteinizing hormone, follicle

stimulating hormone and so on.

Thyroid gland

The thyroid gland is located in the anterior throat. Thyroid follicles

store colloid containing thyroglobulin, a glycoprotein from which

thyroid hormone is derived.

Parathyroid glands

The parathyroid glands are located on the back of the thyroid gland.

These are primarily responsible for causing an increase in blood

calcium levels by targeting bone, the intestine, and the kidneys.

Adrenal glands

The adrenal glands are located above the kidneys in humans and in

front of the kidneys in other animals.

Pancreas

The pancreas is located in the abdomen and is close to the stomach. It

is both an exocrine and an endocrine gland.

Gonads

The ovaries of the female which is located in the pelvic cavity release

two main hormones. While the testes of the male begin to produce

testosterone at puberty in response to Luteinizing hormone.

Pineal gland

The pineal gland is located in the diencephalon. The primary hormone

of this gland is melatonin. It influences the daily rhythms and may

also have an anti-gonadotropic effect in humans. It also regulates the

wake-up and sleep clock and also helps in immunity.

Solved examples for You

Question: Mention the function of thyroid glands.

Answer: The thyroid gland is present in front of the neck. It releases

the hormones triiodothyronine (T3) and thyroxine (T4). They regulate

the body metabolism. Iodine is vital for thyroxine synthesis. Its

deficiency leads to causing goitre.

Reproductive Health

What do you mean by being healthy? Not having fever or cold? No!

Health is a much wider concept. It is basically being free from all

diseases and infections, both physically and mentally. Reproductive

health is an energetic condition, which results from a body’s constant

modification and the ability to adapt in response to stress and changes

in the environment.

Being healthy is necessary for an individual at any age. This becomes

especially important during adolescence. For this, a person needs to be

not only disease-free. In fact, he/she should be physically as well as

mentally healthy and fit. A hygienic life opens the door to a healthy

body and mind. In this chapter, we will discuss the reproductive health

and why it is necessary to be hygienic during adolescence. 

Reproductive Health and Adolescence

According to the World Health Organization (WHO), reproductive

health is the total well-being in all aspects of reproduction i.e., in

behavioral, emotional, physical, and social.

It is very important to maintain a good reproductive health for a

healthy society and population. Adolescence is that stage when a

person experiences growth and sexual maturity. Thus, it is essential to

practice good hygienic habits starting from this stage itself. In order to

ensure proper health, one has to maintain hygiene at a personal level

(personal hygiene). They also have to take care of the hygiene at the

community level (social hygiene).

There are some necessary precautions that you need to take when you

are in your adolescent period. Below are the different ways to

maintain reproductive health during adolescence:

Balanced Diet

A balanced diet is important for people of all age groups. Adolescents

must have a well-balanced diet. This is because our growth depends

on the dietary intake. A well-balanced diet consists of all types of

nutrients like proteins, fats, carbohydrates vitamins, and minerals in an

adequate amount.

Fruits, rice, roti, green vegetables, meat, milk, eggs, etc. are certain

foods that have high nutritional values. However, nowadays, fast food,

bakery products, fried items and other junk foods are gaining

enormous popularity among adolescents. The daily consumption of

fast food has invited many diseases including obesity, vitamin

deficiency diseases, and also affecting the reproductive health both

physically and emotionally.

Personal Hygiene

Personal level hygiene mainly indicates cleanliness, adequate rest and

sleep, physical exercise etc. As we already know, adolescence is the

onset of puberty, therefore, one must be ready to embrace the various

pubertal changes in the body. Sweat glands are more active during this

stage. This could cause more sweating. In addition to this, the hair

growth in public regions and armpit make it even worse.

Hence, you must maintain cleanliness by proper hand washing regular

bathing, washing, and ironing of clothes. Girls have to keep

themselves clean particularly during menstruation. Regular walk,

outdoor games, and workouts are important for adolescents. These

help them remain physically fit and healthy.

Adolescent Pregnancy

As per the Marriage Act, the permitted age for marriage for the girl is

18 years and for the boy is 21. Early marriage before 18 years is not

allowed as the girl is too young and immature. She is not prepared

mentally or physically for motherhood. This could result in mental

agony and other health problems both for the mother and the child.

Solved Example

Question: Why should you say no to drugs?

Answer: As we know, during puberty the hormonal fluctuations levels

are usually very high. This impacts our intellectual and emotional

maturity a big way. This could lead to poor decision making at times.

During this period, adolescents are very susceptible to bad habits like

drinking, smoking, taking drugs, etc. Once someone is addicted to

these habits, it becomes very difficult for them to recover and come

out of it easily. Not only this, but these drugs also affect reproductive

health. They are responsible for causing delayed puberty and both

physical and social consequences.

Reproductive Phase of Life and Sex Determination

Sex Determination: As we grow up, we notice various changes in our

body. Why do they happen? Well, most of it is attributed to

adolescence. Not only you, but each one of us face these changes. It is

absolutely normal! As we all know, adolescence is a transition period

in life between childhood and adulthood. Let’s go through a

reproductive system, menstrual cycle and sex determination in details.

As a part of growth mechanism, the body undergoes a lot of changes

physically as well as psychologically. Puberty commences the sexual

maturity in adolescents. Hormones play a major role during this

period. However, the reproductive phase in boys and girls are

different.

Reproductive System: Menstrual Cycle

Adolescence marks the onset of reproductive phase in boys and girls.

The development of secondary sexual characteristics is the beginning

of this. Once the gonads begin to produce gametes (sperm in male and

ovum in female), they are capable of reproducing. However, the

production of gametes in males and females takes place in different

ways.

Reproductive phase in both females and males begin at puberty. In

males, reproductive phase lasts until death but in females, it ends by

the age of 50 years. Menstrual cycle/ menstruation mark the

commencement of puberty in girls. In a girl, reproductive phase

emerges from the age of 10 to 15 when she attains the puberty. When

puberty arrives eggs in ovaries starts to mature.

One of the ovaries releases the matured ovum in every 28 to 30 days.

This is called ovulation. The uterus becomes thicker and prepares

itself for implantation. If the egg fuses with the sperm it becomes

fertilized. The fertilized egg (egg fused with sperm) leads to

pregnancy.

Contrary to this, unfertilized egg leads to shedding of uterus walls and

causes bleeding in women. Menstruation is the bleeding phase.

Menarche is the first menstrual flow. By the age of 50 years,

menstrual cycle stops forever and is marked as menopause. The time

interval from one menstrual cycle to another can vary from 28 to 30

days.

The sex hormones along with few other hormones are responsible for

this phase in women. The variation in these hormones may change the

ovulation day. The irregularity in menstrual cycle is also attributed to

hormonal imbalances. However, what is interesting to know is how

the sex of a child is determined!

Sex Determination

In the nucleus of every cell in the human body, we have

chromosomes. All the human beings have 23 pairs of chromosomes in

the nuclei of their normal body cells.Out of these 23 pairs of

chromosomes, one pair of chromosomes is called sex chromosome.

The two chromosomes that determine the sex of an offspring or baby

are called sex chromosomes.The two sex chromosomes are named X

chromosomes and Y chromosomes.

The gametes are special cells called reproductive cells.The gametes

contain only 23 single chromosomes and hence, they have only one of

the two sex chromosomes that exist in the normal body cells. In

females, all the gametes or all the egg cells contain X chromosomes.

In males, half of gametes or sperms have X chromosomes and half of

gametes or sperm have Y chromosomes. The baby developed from

XX chromosome of sex chromosome in the zygote is a girl. And, the

baby developed from XY combination of sex chromosomes in zygote

will be a boy.

Solved Example

Question: Write a note on the sex determination of a baby.

Answer: The sex of a baby to be born is decided at the moment the

egg cell of woman gets fertilized by the sperm of man and pregnancy

occurs. The instructions for determining the sex of baby are present in

the sex chromosomes which are in the nucleus of the fertilized egg

called zygote.

● If a sperm carrying X chromosome fertilizes an egg cell which

carries X chromosomes, then the zygote formed will have XX

combination of sex chromosomes due to which the child born

will be a girl.

● If a sperm carrying Y chromosomes fertilizes an egg cell which

carries X chromosomes, then the zygote formed will have XY

combination of sex chromosomes due to which the child born

will be a boy.

The sex of unborn child depends on whether the zygote formed at the

time of fertilization has XX combination of sex chromosomes or XY

combination of sex chromosomes. It is the sperm of man that

determines the sex of the child. This is because half of the sperms

have X chromosomes and other half have Y chromosomes. The egg

cells or ova of woman cannot decide the sex of the child because all

the egg cells contain the same sex chromosomes, X chromosomes.

● If the father contributes X sex chromosomes at fertilization

through its sperm, the baby born will be a girl.

● If the father contributes Y sex chromosomes at fertilization

through its sperm, the baby born will be a boy.

Father is responsible for the sex of the baby which is born.