Video Transcript
What happens if the egg released by
the ovary is not fertilized?
In order to answer this question,
let’s review the anatomy and function of the female reproductive system. The genitals are the outside parts
of the reproductive system. In females, the genitals are called
the vulva. The vagina is the muscular tube
that extends from the external genitals. This is where semen can be
ejaculated during sexual intercourse. The opening to the uterus is a
muscular ring called the cervix. The uterus is a hollow pear-shaped
organ that lies above the cervix and the vagina. This is where the baby develops
until birth. In order for this baby to be made,
an egg cell, or ovum, needs to combine with a sperm cell. The ovaries are the organs
responsible for making ova.
A single ovum can be released by
the ovaries in a process called ovulation. The body prepares for pregnancy
each month by releasing a new egg cell by ovulation. It also prepares for pregnancy by
thickening the uterine lining. This thickened uterine lining is
rich in blood vessels. The ovum is released to a structure
called the fallopian tube, sometimes called the oviduct.
Inside the fallopian tube, an ovum
can be combined with, or fertilized by, a sperm cell that was released by the male
during sexual intercourse. The fertilized egg makes its way
toward the uterus. Once inside the uterus, the
fertilized egg can implant into the thickened uterine lining to start a
pregnancy. It is thickened with many blood
vessels that will nourish the fertilized egg as it develops into a baby.
If there is no sperm to fertilize
an egg, then the egg will be unfertilized. An unfertilized egg will not
implant in the thickened uterine lining. In this case, the thickened uterine
lining will be shed as menstrual blood in a process called menstruation or a
period. This menstrual blood is released
from the vagina along with the unfertilized egg each month pregnancy doesn’t
occur. The cycle can then repeat again
with an egg cell being released by the ovary and the uterine lining again thickening
in preparation for a pregnancy. This cycle occurs each month.
Therefore, the name of the process
that occurs when an egg is not fertilized is called menstruation.
