Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed. Until the maturation of their reproductive capabilities, the pre-pubertal physical differences between boys and girls are the external sex organs. On average, girls begin puberty around ages 10–11; boys around ages 11–12. Girls usually complete puberty around ages 15–17, while boys usually complete puberty around ages 16–17. The major landmark of puberty for females is menarche, the onset of menstruation, which occurs on average between ages 12–13; for males, it is the first ejaculation, which occurs on average at age 13. In the 21st century, the average age at which children, especially girls, reach puberty is lower compared to the 19th century, when it was 15 for girls and 16 for boys. This can be due to any number of factors, including improved nutrition resulting in rapid body growth, increased weight and fat deposition, or exposure to endocrine disruptor such as xenoestrogens, which can at times be due to food consumption or other environmental factors. Puberty which starts earlier than usual is known as precocious puberty. Puberty which starts later than usual is known as delayed puberty. Notable among the morphologic changes in size, shape, composition, and functioning of the pubertal body, is the development of secondary sex characteristics, the "filling in" of the child's body; from girl to woman, from boy to man. Derived from the Latin puberatum (age of maturity), the word puberty describes the physical changes to sexual maturation, not the psychosocial and cultural maturation denoted by the term adolescent development in Western culture, wherein adolescence is the period of mental transition from childhood to adulthood, which overlaps much of the body's period of puberty.

3. Development of Breasts
 Between 7-13 years, girls start
developing breasts.
 Morphologically (that is in terms of
form and shape), breasts look like a
cone with the base at the chest
wall and the apex at the nipple.

5. Appearance of Hair in the
Armpit
 During puberty, hair begins to
grow in arm pits.

7. Widening of Hips and
Appearance of Pubic Hair
 The hips of a girl widen.
 Hair begins to grow in the genital
region. (pubic hair)

9. Growth Spurt
 girls experience a sharp
growth in their height.
 known as growth spurt.
 16 years old: attains about
98% of the final height.

11. Onset of Menstruation
 Menstruation is a process in
which a sexually mature girl's or
a woman's body releases of a
small amount of blood and tissue
through her vagina.

14. Broadening of Chest and Shoulders
 Onset of puberty brings many
physical changes in boys. Their chest
and shoulders broaden and their
muscles start to develop.

16. Deepening of Voice and Appearance
of Facial Hair
 The voice gets deeper.
 Hair begins to grow on the face that
later develop into moustache and
beard.

18. Appearance of Body Hair and
Pubic Hair
 Hair begins to grow on the chest, in
the armpits, hands, legs and in the
groin area.
 Hair in the groin region is called
pubic hair.

20. Increase in Size of Genitals
 The penis and the testicles
grow bigger in size.

22. Growth Spurt
• During puberty boys experience
a rapid growth in height over a
span of 2 to 3 years.
• This rapid growth in height is
called growth spurt.

24. Ability to Ejaculate
 Capable of ejaculating which is
ejection of semen through the
penis.
 The first ejaculation marks the
attainment of sexual maturity in a
boy's life.

26. Effects
of
Puberty Changes

28. Feeling Overly Sensitive
 During puberty, since the body
undergoes many changes, it is
common to feel uncomfortable
about them and become overly
sensitive about your physical
appearance.

30. Looking for an Identity
 Since you are in the process of
becoming an adult, you may
feel inclined to figure out what
makes you unique as a person

32. Feeling Uncertain
 Since you're not completely an
adult and are not a child
anymore, puberty can potentially
lead to uncertain times.

34. Peer Pressure
 With the onset of puberty, the
conversations with your friends
will increase.
 Your peer group and you are
likely to be influenced by what
you see around you in popular
media and the culture that is
represented through them.

36. Conflicting Thoughts
 Since you are somewhere in
between as a teenager during
puberty, you may feel stuck
between how you were as a
child and how you wish to be
as an adult.

38. Mood Swings
o To add to the uncertainty
and conflicting thoughts,
you may also experience
frequent and sometimes
extreme changes in your
mood.

40. Feeling Conscious about Self
o The onset of puberty can vary
on an individual basis.
Therefore the way you grow
maybe different from the way
your friends grow.
o This can make you conscious
about the way you're growing
up and your body.

42. Getting Sexual Feelings
o One aspect of sexual maturity
is being curious about sex and
also about bodies of people
that you are attracted to.