Transcript Female Reproduction - Helena Public School District

Female Reproduction
Female Reproduction
Female Reproduction
 The most important part
of the female
reproductive system are
the ovaries
Two Functions of the Ovaries
 Production of ova
 Secrete hormones
Primary Follicles
 At birth the ovaries
contain many small sac
like structures that
contain immature ova
called primary follicles
Primary Follicles
 It is estimated that there
are 200,000-400,00
primary follicles in each
ovary at birth
Primary Follicles
 It is estimated that there
are 200,000-400,00
primary follicles in each
ovary at birth
 By age 50 most of them
have degenerated.
Puberty
 At age 8 the pituitary
gland sends hormonal
messages to the ovaries,
stimulating them to
release estrogen into the
circulatory system.
Puberty
 Between the ages of 1114 the hormonal
message becomes
stronger thus bringing
about the physiological
changes known as
puberty.
 During this time the
ovaries release estrogen
into the circulatory
system.
Estrogen
 Estrogen is responsible
for the primary and
secondary sex
characteristics.
Primary Sexual Characteristics
 Increase in the size and
physiological maturity of
the fallopian tubes,
uterus and vagina.
Secondary sexual characteristics
 Sex desire
 Body hair growth
 Breast development
 Feminine body features
 Ovulation
 Menstruation
Female Ovulation
 Each month 15-20
immature follicles begin
to grow and develop,
usually one of these will
balloon outward to full
maturity. This one is
called the graafian
follicle.
Pituitary Gland
 Simultaneous with the
development of the
stigma the pituitary
gland increases its
output of LH (Luteinizing
Hormone)
Ovulation
 LH causes the stigma to
rupture causing
ovulation.
 Once ovulation has
occurred the egg cell
may be fertilized within
12-36 hours. After
which it begins to
degenerate.
Ovulation
 The fallopian tubes
gathers the egg by its
fimbriated ends called
ampulla and by the
current created by the
motion of the cilia.
Ovulation
 Once ovulation has
occurred the follicular
remains are transformed
into a temporary
endocrine gland called
the Corpus Luteum.
Ovulation
 To prepare the
reproductive system for
the reception of the
fertilized egg the corpus
luteum secretes two
important hormones:
estrogen and
progesterone
Hormones
Estrogen and progesterone are responsible for preparing
the female reproductive system for reception of the
fertilized egg.
Ovulation: Proliferative Phase
 Initiated by estrogen
causes a rapid growth of
endometrial cells.
Ovulation Secretory Phase
 Initiated by progesterone
causing an increase in
blood supply to the
uterus
 Acting together these
hormones build and
maintain the
endometrium
anticipating the reception
of the fertilized egg.
Fertilization
 If fertilization occurs the
endometrium grows to a
thick, blood vessel-rich,
tissue layer. This
represents an optimal
environment for the
implantation of a
fertilized egg upon its
arrival in the uterus.
Menstrual Phase

If fertilization fails to take place
phase three of this recurring cycle
is initiated:

Menstrual Phase: Approximately
24 hours prior to menstruation the
blood supply to the uterus is shut
off. In the absence of the blood
supply the lining of the uterus
endometrium dies. The dead
tissue together with 1) a small
quantity of blood in the uterine
cavity initiates uterine
contractions. These contractions
expel the contents of the uterus as
the menstrual flow.

The menstrual flow last
approximately 7 days after which
the cycle starts again.