The document discusses changes that occur in the human body during two periods of rapid development - infancy and puberty. It then provides details on the sexual characteristics and fertility cycles of both males and females. For females, it describes the menstrual cycle and signs of fertility such as cervical mucus. For males, it explains sperm production and storage, as well as signs like nocturnal emissions. Finally, it outlines the five stages of secondary sex characteristic development for both sexes during puberty.

1. The Human Body
BY: MR. B

2. Changes…
• There are two periods in life when the human body changes rapidly and
dramatically.
• Babies: In first year of life, babies usually triple their weight and at two and a
half years they have reached half of their adult height.
• Puberty: The shape of the body changes, there are obvious signs of the
development of fertility and growth spurts result in rapid height and weight
gain. Even the appearance of the face is changed because of the facial
bones.

3. Sexual Characteristics Review
• Primary Sexual Characteristics:
• The development of fertility, which is the capacity to reproduce.
• Secondary Sexual Characteristics
• The external changes in the body that make the appearance of each sex
distinctive.

4. Female Fertility
Ovum
Cycle

5. Not how we’ll learn about this…

6. • Female Fertility is usually described as a “cycle”, which means that a series
of events are repeated again in the same order.
• Female Fertility Cycle begins with menstruation and ends when the next
menstrual period begins.
• Most cycles last from three to five weeks, and include a short period of
fertility, and a longer period of infertility.
Female Fertility

7. Female Fertility Cont.
• Three regular events that occur during the adult female cycle are:
• Menstruation – Shedding the lining of the uterus
• Ripening of an ovum in one of the ovaries
• Ovulation – Fully ripened ovum moves into the fallopian tube, which leads to the
uterus.
Women are fertile just before and after ovulation.

8. Signs of Female Fertility
• As the ovum begins to ripen, the ovaries send a signal to the cervix to
product mucus.
• At first the cervical mucus is quite thick.
• As ovulation approaches it becomes thinner
• The purpose of cervical mucus is:
• To nourish and prolong the life of sperm cells.
• Guide and carry sperm toward the Ovum.
• Filer out abnormal or immature sperm cells.
• After ovulation the mucus thickens again and forms a barrier or plug at
the opening of the uterus.

9. FEMALE REPRODUCTIVE SYSTEM

10. Female Fertility Key Terms
• Some time after girls begin to mature they experience these signs of their fertility.
• Menstruation
• A sign the uterus has begun the task of building a lining.
• Cervical Mucus
• A sign ovulation is occurring

11. Male Fertility
Erection

12. Male Fertility
• Unlike Female Fertility, it does not occur in a cycle. Physically mature
males always have the ability to reproduce.
• Male fertility begins with the production and storage of sperm cells inside
the testicles.
• Sperm cells must move out of the storage areas and mix with several
fluids, which protect and nourish the sperm. This mixture is called Semen.
• The sperm and fluid is expelled from the body through the penis by a
process called Ejaculation.

13. Signs of Male Fertility
• The process of producing and storing sperm cells usually begins when
boys are between 12 and 16.
• Only a limited amount of sperm can be stored inside in the body. In
order to make room for new sperm cells, semen is cleared out of the
body periodically.
• This can happen gradually or all at once through Ejaculation.
• This often occurs during sleep, and so it is called a Nocturnal Emission.

14. Male Reproduction System

15. Secondary Sexual Characteristic Stages
Stage Boy Girls
1 No physical development is evident, but internal changes have begun. There are rising levels of
hormones in the blood stream; the testicles are maturing and the ovaries are enlarging
2 Age: 10-14
-Gain weight and height.
-Testicles and scrotum enlarge; penis
remains the same size.
-First signs of pubic hair are evident.
Age: 8-13
-First signs of breast development.
-Height and weight begin to increase.
-First signs of pubic hair are evident
3 Age: 11-16
-Testicles and scrotum continue to grow;
penis lengthens.
-Pubic Hair thickens
-Height and weight increase, and
shoulders broaden.
-As larynx enlarges, the voice begins to
deepen
Age 9-15
-Breasts continue to grow.
-Pubic Hair coarsens and darkens.
-Cervical mucus appears and late in this stage girls
may menstruate for the first time.
4 Age: 12-17
-Penis length and width increases;
testicles continue to enlarge.
-May experience first nocturnal emission.
-Voice deepens and skin becomes oilier.
-Underarm hair appears and some boys
may have facial hair on chin as well as
upper lip
Age: 12-13
-Underarm hair begins to develop.
-Breasts continue to develop and menstruation is likely
to begin.
-Ovulation may not occur yet.
-Pubic Hair is more adult in appearance.

16. Secondary Sexual Characteristics Stages
Stage Male Female
5 Ages: 14-18
-Development of genitals and pubic hair is
complete.
-Growth spurts slow down and body is shape
of a mature male.
-Boys typically begin shaving.
-Depending on their genetics, some may
continue to develop body hair on their
upper body for several years.
Ages: 15-16
-Have the body of a mature woman; full breast
development.
-Full adult height as been reached.
-Sometime during this stage ovulation begins to
occur with some regularity.