Female Reproduction
(Illustrations are in your health book p. 330-331)
Female Reproductive organs
Most of a female’s reproductive organs are located on the inside of the body and are
protected by the pelvic girdle. The organs which are located on the outside of the body are
called genitals.
A female’s genitals are covered by two folds of skin called the labia and are of moist with
mucus on the inside surfaces. The folds of skin cover the opening of the vagina and a small
organ towards the top of the folds called the clitoris. The clitoris has many nerve endings and
blood vessels which makes it very sensitive, similar to the top (glans) of the penis.
There are two openings beside the vagina that are not considered part of the reproductive
system but are in the location of the genitals. The first is the urethra which is positioned just
behind the clitoris and releases urine out of the body. The anus is the second opening which sits
behind the opening of the vagina and allows solid waste to leave the body.
Functions of the Female Reproductive Organs
At puberty the female sex organ which is called the ovary begins to produce both female
hormones and eggs. Estrogen is one of the hormones being produced and it is responsible for the
development of female traits such as hips broadening and breast development along with other
characteristics. Another hormone produced in the ovary is progesterone and its primary
responsibility is to prepare the uterus for pregnancy, as well as supply the breasts with milk after
the baby is born.
The egg travels from the ovary through the fallopian tube to the uterus. The fallopian
tube is where most fertilization takes place and its main purpose is to move the egg to the uterus.
Once the egg enters the uterus or womb, it will attach itself to the side of the uterine wall where
it will be provided nourishment and an opportunity for growth. This pear shaped organ is about
the size of a fist and has the capability of expanding to meet the size of a baby. An average size
baby is 15-20 inches long and weighs about 6-10 pounds. After the baby is born the uterus will
return to normal size in about 6 weeks.
The cervix is located at the lower end of the uterus and is also referred to as the neck, due
to the fact that it is smaller than the rest of the uterus and keeps the baby from falling into the
vagina. During labor, the cervix will open up allowing the baby to be pushed through into the
vagina, also know as the birth canal, and then delivered out the body.
The hymen is a small ring of tissue which partially covers the opening of the vagina. It
can be broken during rigorous activity or inserting a tampon into the vagina. Some women do
not have one at all and it does not serve any real function in the reproductive system.
Female Sex Cells
The female sex cells are called eggs and are located in the ovaries. The sex cells contain
½ of the genetic material needed to produce a baby. All females are born with all the eggs they
will need in their lifetime; however they are not mature and will lie dormant (asleep) until after a
girl begins puberty. Each immature egg lies within a case of tissue called a follicle. At the onset
of puberty, the pituitary gland located at the base of the brain begins to send hormones to the
ovary to start maturing eggs. There are two ovaries in the female reproductive system, one on
the left side of the body and one on the right. Every other month one of the two ovaries matures
the eggs preparing for ovulation. Ovulation is where the breaks away from the follicle and
moves out of the ovary into the fallopian tube. The egg travels through the fallopian tube to the
uterus. The cilia, which are hair-like fibers located in the fallopian tube, move in a sweeping
motion to help push the egg to the uterus, where if fertilized will grow for the next 9 months.
Fertilization is the joining of an egg cell with a sperm cell. Most of the time fertilization
occurs in the fallopian tube. Of course, if there is an absence of either the sperm cell or egg cell
than fertilization can not take place.
Ovulation – Menstruation Cycle
A normal ovulation-menstruation cycle is between 26-32 days with the average being 28
days. The menstrual period is the number of days in which there is a release of blood rich tissue
from the body. It can last anywhere from 2-8 days on average. During adolescence the cycles
are sometimes irregular which means it will not be the same number of days each month. The
cycle begins on the first day of a girl’s period and goes until the first day of the next period.
There are many changes that occur within the body during the cycle. First, the pituitary gland
releases a follicle stimulating hormone which begins to mature about 10-20 eggs in the first 5
days. The next 8 days the ovaries increase their production of the hormone estrogen which helps
thicken the lining of the uterus. At the mid point of the cycle ovulation occurs due to the release
of another hormone called Luteinising hormone (LH) which causes the release of the egg from
the follicle. The last half of the cycle, the ovary produces the hormone progesterone to give
nourishment to the fertilized egg. If no fertilization occurs the ovaries shut down the production
of progesterone which will cause the uterus to begin to break down the blood rich tissue. The
last 2-3 days of the cycle cramping begins to occur prior to menstruation. During menstruation
the body loses about 2 ounces of blood rich tissue.
Fertilization
Fertilization occurs after a female and male have had sexual intercourse where the sperm
has been ejaculated into the vagina. The sperm then travels upward through the uterus and into
the fallopian tubes. Fertilization only occurs if an egg is present in the fallopian tubes or uterus.
The egg is present in the fallopian tube after ovulation or mid cycle for about a day and then
moves to the uterus where is survives another day or two if it hasn’t been fertilized.
The Developing Baby
Once the egg is fertilized it begins the process of developing the baby. The egg cell
divides over and over again which forms a cluster of cells. After about 3 days the fertilized egg
reaches the uterus where it attaches itself to the side of the uterus. Once it is attached to the side
of the uterus an organ is formed called a placenta and is made up of blood rich tissues from the
lining of the uterus. This organ is where mother and baby exchange materials. The umbilical
cord is connected to the baby and the mother through the placenta and it passes nutrients to the
baby from the mother’s blood and wastes from the baby are carried back to the mother.
However, the mother’s blood and the baby’s blood never mix because they may not be the same
blood type. The baby is protected by a sac of water-like fluid known as amniotic fluid.
It usually takes a full nine months for the baby to completely develop. During the nine
months both the baby and mother go through significant changes that should be monitored by a
doctor. The doctor will give suggestions on ways to keep both mother and baby healthy. This
type of care is called pre-natal or “before birth” care.
Answer the following questions on a separate sheet of paper.
Define the following terms
1. fertilization
2. follicle
3. ovulation
4. placenta
5. pregnancy
6. prenatal
7. uterus
Answer the following questions in complete sentences.
8. How does the role of estrogen differ from that of progesterone?
9. What two things must be present in the fallopian tubes for fertilization to
take place?
10. Explain how fertilization of an egg affects the process of menstruation
11. About how long is an ovulation-menstruation cycle?
12. How does a developing baby receive food and oxygen?
13. Put these terms in the order in which an unfertilized egg travels through
them: cervix, uterus, follicle, fallopian tube, vagina