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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.