Merciful 1/Merciful - Disc 1.iso/software/b/birds_&_bees/bird&bee's.dms/bird&bee's.adf/repro2.all

Text File | 1986-06-21 | 7KB | 219 lines

    We have already learned that two
ingredients are necessary to create a
baby: the sperm, supplied by the
father, and the egg, supplied by the
mother. We will now learn some new
words and look at this process in more
detail.
    A sperm cell looks like a little
tadpole (although you need a microscope
to see it). It has a big head and a
long whip-like tail. Just like tad-
poles, sperm live in and move around in
liquid. 1The man's body produces semen,
a thick milky fluid to allow the sperm
to swim to their destination] -- the
female ovum (egg).
    3When a man and woman decide that
they would like to make a baby, they
engage in sexual intercourse. This is
the name given to the act of placing
the penis inside the vagina and releas-
ing thousands of tiny sperm cells (eja-
culating).]
    The couple starts by sexually
arousing one another. This foreplay has
two physiological purposes. It prepares
the woman's vagina to accept the penis
by releasing lubricating fluids. The
stimulation to the penis causes an in-
crease in the flow of blood to this
area resulting in its getting much
harder and firmer. The erection of the
penis is important because 2the normal-
ly soft penis] would have a difficult
time penetrating (getting into) the
vagina. The stimulation also tells the
sperm to get ready to leave the man's
body and prepare for the journey
through the woman's vaginal canal
towards the egg.
    When the penis reaches a point of
extreme excitement (climax), 4the semen
squirts out the hole in the end of the
penis (called the urethra or urethral
opening).] This is called an ejacula-
tion, and it allows the sperm to begin
swimming through the vaginal passage,
into the uterus, and possibly all the
way to the Fallopian tubes where they
might find an egg to fertilize.

*
2Are sperm and semen two names for the
same thing?
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2Is the male penis normally firm and
erect?
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1In order to impregnate (make pregnant)
a woman, must the man have an erection,
enter the woman's vagina, and
ejaculate?
$
2Does the tip of the penis have two
little openings, one for urine and the
other for semen?
$
@
    Once they are released in the vagi-
nal canal, the sperm must try to stay
alive long enough to travel to the
Fallopian tube. There may or may not be
an egg cell to be fertilized. 1Only
once every four weeks does the ovary
release an egg cell.] 2The egg cell
moves slowly through the Fallopian tube
where, for a period of a day or two, it
is capable of becoming fertilized by a
sperm cell.]
    If the egg cell is united with a
healthy sperm cell, the now fertilized
egg will continue moving through the
Fallopian tube until it reaches the
uterus, where it will reside for the
next nine months. All during this time,
the sperm and egg cells are multiplying
rapidly, beginning the growth process
of the embryo. This is called the ges-
tation period or pregnancy. It will be
discussed in more detail in the next
lesson.
    3If the egg does not become ferti-
lized, it becomes part of the menstrual
flow.] This is what happens most of the
time. That is why women have their
periods every month, but have babies
much less frequently. During the preg-
nancy, no more eggs are released so
there is no reason to have the menses
(period).

*
2Can a woman can get pregnant every
time she has intercourse?
$
2Do the sperm and egg unite (fertilize)
in the uterus?
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2Does an unfertilized egg remain in the
uterus for nine months?
$
@

    1Pregnancy refers to the process of
gestation, approximately nine months
long. It is usually broken up into
three trimesters, each one of about
three months. During the first
trimester (the first, second, and third
month after fertilization) the embryo
develops very rapidly. By the end of
these three months it is only two to
four inches long and weighs less than
one ounce. It is now called a fetus and
has already developed several
recognizable body parts.
    In the second trimester (months
four to six) the fetus develops muscles
and is able to move its arms and legs.
By the end of the sixth month, the
fetus is a little over a foot long (12
inches) and weighs somewhere around 2
pounds. 2If for some reason it is born
prematurely (early) it is sometimes
possible for this partially developed
fetus to survive.] The causes of these
premature births are not fully under-
stood, but medical advances have made
it possible to keep these premature
infants alive outside of the womb (al-
though some may develop physical and/or
mental problems).
    During the final trimester (the
last three months of the gestation
period) the fetus continues growing
rapidly and is preparing itself for
life outside the womb. Most babies are
born around two hundred and sixty six
days after conception and weigh six to
eight pounds.

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2Must the embryo develop in the womb
for nine months?
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1Can a baby be born before nine
months and still be normal?
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@

    Most babies are born head first,
being forced out the vagina without
much difficulty (1although the mother
must exert considerable effort and
endure often intense pain]). However,
2there are several common complica-
tions that can occur.]
    One of these is when the baby's
feet instead of its head are pointed
toward the vagina. This is called a
breech birth. Another is when the baby
gets stuck and must be pulled out
(using a tool called a forceps). A
third is when the baby is removed
through a cut made in the lower abdomen
rather than out the vagina. This fairly
common technique is called a Cesarean
section or C-section for short. These
complications will be explained in more
detail when you are older.
    In the United States almost all
babies are born in a hospital or birth-
ing center. A doctor or midwife usually
helps in the delivery of the baby. (A
midwife is a person, other than a doc-
tor, who is trained to deliver babies.)
After the baby is born the doctor or
midwife will tie and cut the umbilical
cord. The umbilical cord connects the
baby with the mother's insides (speci-
fically the placenta). It had been the
source of food for the fetus. 3Now that
the baby is outside the mother and
ready to live on its own, the umbilical
cord and placenta are no longer
needed.]
    The nurse or midwife will also
clean the baby, removing the placenta
and fluids (that the fetus was living
in) from the infant's hair and body.
(The placenta is the lining of the
uterus that will emerge with the
infant.)
*
2Is delivering a baby always easy
for the mother?
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1Are there many things that can go
wrong during the time of delivery that
endanger the mother or the child?
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2Are the placenta and umbilical
cord useful after the birth of the
baby?
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