Page 107 - Science Class 08
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Reaching the Age of Adolescence
• Adolescence • Puberty
• Changes of uberty P • Secondary Sexual Character
• Endocrine lands G • Reproduc ve hase of ife in umans P L H
• How is the Sex of the Baby Determined? • Reproduc ve Health
In previous chapter, you have studied about PUBERTY
sexual reproduc on in human beings. You have Sexual and other physical matura on that
also studied how reproduc on occurs in human occurs during puberty is a result of hormonal
beings. In this chapter, you will study some changes. In boys, it is difficult to know exactly
more related topics to reproduc on in human when puberty is coming. There are changes
beings like the age required for the reprodu- that occur, but they occur gradually and over a
c on, major changes in the body of boy as well period of me, rather than as a single event.
as girl during this period and the harmones
CHANGES OF PUBERTY
responsible for these changes.
While each male adolescent is different, the
ADOLESCENCE
following are average ages when puberty
The teenage years are also called adolescence. changes may occur:
Adolescence is a me for growth spurts and v Beginning of puberty : 9.5 to 14 years old
puberty changes. An adolescent may grow
v First pubertal change : enlargement of the
several inches in several months followed by a
tes cles
period of very slow growth, then have another
growth spurt. Changes with puberty (sexual v Penis enlargement : begins approximately
one year a er the tes cles begin enlarging
matura on) may occur gradually or several
signs may become visible at the same me. v Appearance of pubic hair : 13.5 years old
There is a great amount of varia on in the rate v Nocturnal emissions (or “wet dreams”): 14
of changes that may occur. Some teenagers years old.
may experience these signs of maturity sooner v Hair under the arms and on the face, voice
or later than others. change and acne : 15 years old
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