THE FEMALE SEX GLANDS
Like the testes, the
two ovaries have more than one function. They produce the ova, or eggs; they
also secrete hormones needed for both reproduction and feminine
characteristics. The ovaries lie in the front part of the abdomen, below the
navel, and each is connected with the uterus by a fallopian tube.
The ovarian
hormones are estrogen and progesterone. They are produced in small amounts
before puberty and after menopause, and in abundance during the childbearing
years, the period when a woman has her regular monthly cycles.
MENSTRUATION AND OVULATION
Menstruation involves
the discharge of the extra blood and tissue built up in preparation for
conception but not used. Cycles vary among women and even in the same woman,
but generally the time from one menstrual period to the next averages about 28
days. Doctors customarily count the first day of menstruation as day 1 in a
cycle. During the first 14 days of the cycle, the ovary contains a follicle, a
small hollow ball about the size of a pinhead. Within the follicle is an egg.
The follicle grows during the two weeks until it becomes about as large as a
pea.
As it grows, it produces estrogen. Follicle growth as well as the
menstrual cycle in general is under pituitary gland control. On about day 14,
stimulated by the pituitary, the follicle bursts and the egg is discharged from
the ovary to enter the fallopian tube on its way to the uterus. If sperm are
present in the tube at this time, fertilization may take place in the tube. The
fertilized egg then continues its journey to the uterus where it implants
itself on the wall of the uterus.
Meanwhile, the ruptured follicle from which the egg carne is
transformed into a yellowish, solid ball, now called the corpus lute urn, or
yellow body. The corpus luteum produces a second hormone, progesterone.
Scientists now know how to make synthetic hormones to control ovulation.
Contraceptive pills imitate the natural body processes in preventing ovulation,
as discussed elsewhere in this book.
Estrogen and progesterone help build up
the lining of uterus, making it thicker and providing it with a rich blood
supply to feed the unborn baby. During the last 14 days of the cycle, the two
hormones are produced by the corpus luteum. The fertilized egg secretes a
hormone that causes the corpus luteum to persist in producing estrogen and progesterone
from the fertilized egg is necessary because at the end.Pregnancy has not
occurred, the corpus luteum degenerates and its retions stop.
With cessation of
hormone production, the rich blood supply built up in the uterine lining
sloughs off and menstruation occurs. Menstruation and menstrual difficulties
are discussed in detail elsewhere in this book.
Menopause, or change
of life, is as natural for women as menstruation is. There should be no dread
of it: nothing more disastrous occurs than the tapering off and cessation of
the monthly cycle. True, some changes, natural ones, occur. Estrogen secretion
is reduced. The follicles no longer release eggs. Menstruation stops, suddenly
or gradually.
After menopause is well established, in about a year, there
should be no more bleeding. Be certain to consult a physician immediately if
bleeding or spotting occurs, since this may signal cancer or an- other disorder
requiring prompt treatment. Actually, unfounded fears are to a large extent
responsible for the emotional disturbances some women experience during
menopause.
Certain physical symptoms may occur because of the glandular changes
taking place. If they become troublesome, they may be relieved by hormone
treatment. We discuss menopausal symptoms more fully elsewhere.
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