For Education purposes only. Sex Education/ Secondary Level.

2. • You have learned that two structures
in plants are important for sexual
reproduction. These are the Pistil and
the Stamen.
• In many animals two kinds of
individuals produce sex cells or
gametes. The males produces sperms
and the females produce eggs.

3. THE SPERM AND THE
EGG CELLS

4.  Where do sperm and the
egg cells develop?
 How do these gametes
look like?

5.  You have seen that plants
have specific reproductive
structure for the gametes.
The same is true with
animals. They, too, have
specialized organs for
reproduction.

6.  In human beings, the
sperms are produced in the
testes of the male, and the
eggs are produced in the
ovaries of the female.

7.  The sperms are
small with long
tails to move
around fast.

9.  The egg cell is
round and does not
move on its own.

11. THE MALE
REPRODUCTIVE
SYSTEM

13.  The principal male reproductive
structures are the testes, which are
enclosed in a scrotal sac or scrotum.
Each testis is composed of two parts:
the seminiferous tubules where the
sperm cells are produced, and the
interstitial cells which secrete the
male sex hormone.

14.  What is Sex Hormone?
- Sex hormone is a
chemical substance which
influences the function of
the testes.

15.  Mature sperm cells pass from the
seminiferous tubule through many
tiny tubes into the epididymis, which
lies on the surface of the testis.
The sperms are stored in the
epididymis until they are released
during sexual intercourse.

16.  The epididymis continues into a long sperm
duct, called vas deferens, which joins the
urethra.
The urethra passes through the penis and
empties to the outside.
In human male the urethra, is a common
passageway used by both urine and sperms.
However, the opening of the urinary bladder
to the urethra opens only during urination

17.  As sperm pass through the vas deferens
and urethra, seminal fluid is added to
form semen.
 The semen, consist of seminal fluid and
sperm cells.
 The seminal fluid is secreted by three
glands, namely, the seminal vesicle,
prostate gland, and the Cowper's
gland.

18.  The seminal fluid has several
functions;
 It carries the sperms and lubricates the
passage through which the sperms
travel.
 It also protects the sperms from the
harmful effects of acids in the female
reproductive canal.

19.  The penis is the male external
reproductive organ. Passing through
the penis, the urethra opens to the
outside.
 During sexual intercourse, the semen
containing the sperms is deposited by
the penis into the reproductive canal of
the female.

20.  Two parts of the penis are
important; Glans penis appears as
the expanded tip and is very
sensitive. Another is Erectile tissue
that lie on all sides around the
urethra. These tissues cause the
penis to erect during sexual
excitement.

21.  A fold of skin, called the
prepuce, over the glans penis is
usually removed a few days
after birth but removal can be
done at any age. This procedure
is called circumcision.

22.  When penis is stimulated, the arteries
leading into the penis dilate, and the veins
from the penis constrict. The muscles in
the walls of the epididymis, vas deferens,
seminal glands, and urethra contract.
 These contractions move the sperm-
bearing fluid combine forming the semen.
Then this expelled through the urethra.

23. The process of releasing semen
through the urethra is called
ejaculation.
An average of 100 million sperm
cells in about 3.5 ml of semen is
released during one ejaculation
by a human male.

24. THE FEMALE
REPRODUCTIVE
SYSTEM

27. THE
INTERNAL
STRUCTURES

28.  The female reproductive structures are
the ovaries and their ducts which are
located in the lower part of the
abdominal cavity. They are held in place
by large muscles.
 The ovaries have two main functions:
the production of egg cells and the
secretion of sex hormone.

29.  At birth, a girl's ovaries already contain a
large number of underdeveloped egg cells
enlosed in follicles.
 A follicle is a baglike structure that contains
an egg cell.
 As the female matures, the follicle grows
bigger and develops a cavity filled with fluid.
 The ripe follicle containing the egg bulges
from the surface of the body.

30.  When ovulation occurs, the outer wall
of the follicle breaks. The fluid and the
detached mature egg are then
expelled.
 In human body, only one egg is
normally released each month. There
is no apparent regularity as to which
ovary will release eggs at any given

31.  A ripe egg is released from the ovary into the
abdominal cavity. Once released, the egg is drawn
into the funnel-shaped end of one of the oviducts or
fallopian tubes.
 The fallopian tube partly surround the ovaries but
they are not connected.
Cells lining the funnel of the fallopian tubes produce
currents that help move the egg into his duct.
If sperm are present in the fallopian tube, the egg is
fertilized.

32.  Each fallopian tube empties directly
into the upper end of the uterus.
 The uterus which about the size of
a first lies in the lower portion of the
abdominal cavity just behind the
bladder. It has very thick, soft,
muscular walls with many blood
vessels.

33.  If an egg is fertilized as it
moves down the fallopian
tube, it becomes implanted
in the wall of uterus and
develops there until the
time of birth.

34. THE
EXTERNAL
STRUCTURES

35.  At the lower part of the uterus is a
muscular ring of tissues called the
cervix.
 The cervix is connected to a muscular
tube, called the vagina.
 The vagina is an external structure
that receives the penis during sexual
intercourse.

36.  During sexual intercourse,
the vagina secretes a
watery substance which
acts as lubricants to
facilitate the entrance of the
penis.

38.  The mons pubis is a fleshy rounded
elevation just below the abdomen. The mons
pubis is covered with hair at the age of
puberty.
 The labia majora are two folds of skin that
pass from the mons pubis to the anal region.
They are pigmented and covered with hair.
 The clitoris is between the labia minora
above the urinary opening.

39.  The labia minora are two folds of skin
surrounding the vaginal opening below the
clitoris.
 The vaginal opening, which is located
below the urethra, leads to the muscular
vagina.
 Before the first sexual intercourse, the
opening of vagina in females is partly
closed by a thin membrane called hymen.

40. HORMONES IN
HUMAN
REPRODUCTION

41.  Puberty in human beings is the stage in
which their sex organs start to function.
This occur at about 12 years of age. No
sperms or eggs are produced before
puberty.
 This stage starts with the secretion of
chemicals by the hypothalamus of the
brain and the pituitary gland.

43.  The hypothalamus secretes a hormone that
stimulates the pituitary gland to secrete
different hormones.
 Hormones are substances that regulate or
control the activity of certain tissues and
organs.
 A structure that secretes a hormone directly
into the bloodstream is called an endocrine
gland.

44.  The pituitary gland is an
example of an endocrine gland. It
secretes two hormones that
influence the ovary and the
testes. They are the follicle-
stimulating hormone (FSH) and
the luteinizing hormone (LH).

45. MALE SECONDARY
SEX
CHARACTERISTICS

46.  In males the follicle-stimulating
hormone (FSH) stimulates the cell in
the lining of the seminiferous tubules
to divide and develop into sperms.
 At the same time the luteinizing
hormone (LH) stimulates the
interstitial cells to secrete a hormone
called testosterone.

47.  Once testosterone is adequate, it brings
about the changes normally associated
with puberty.
These are changes among males are the
growth of beard, growth in hair in armpit
and in areas near the external
reproductive structures, and change in
voice. Inside the body the seminal vesicle
and and prostate gland develop.

48.  These changes are commonly
called secondary sex
characteristics.
 In some cases a boy may ejaculate
as early as 13 or 14 years old. The
seminal fluid, however, may not
contain mature sperms until one or
two years later.

49. FEMALE
SECONDARY SEX
CHARACTERISTICS

50.  As in the male, puberty in the female
begins when the pituitary releases the
follicle-stimulating hormone (FSH) and
the luteinizing hormone (LH).
 These two hormones cause the
maturation of the ovaries. Once the
ovaries mature they secrete the female
sex hormones, estrogen and
progesterone.

51.  The sex hormones, particularly
estrogen, stimulate the development of
female secondary sex characteristics
such as growth of hair in the armpit and
around the external reproductive
structures, broadening of the hips,
development of the breast, increase in
the size of uterus and vagina, and the
start of the menstrual cycle.