The Sperm's Odyssey
in the Female Reproductive Tract
A million million spermatozoa,
All of them alive;
Out of their cataclysm but
one poor Noah
Dare hope to survive.
Aldous Huxley
When a man and woman have sexual
intercourse, the man places his erect penis inside the woman's vagina.
Here it releases millions of sperm when ejaculation occurs. Once the sperm
have been deposited here they have a long and arduous journey ahead of
them, like salmon entering the mouth of a river to swim upstream to spawn.
Some of the sperm swim straight up into the fallopian tubes through the
cervix and uterus - and some of them are so fast, that sperms have been
found in the tubes in as little as a few minutes after ejaculation. Some
sperms die in the acidic vaginal fluid; and some enter the cervical mucus
and cervical crypts. They are stored here and can remain alive here for
as long as 48 to 72 hours. During this time, the sperms are released in
small numbers and these continue to swim towards the fallopian tubes. This
is why you don't need to have sex every day to get pregnant even though
the egg remains alive for only 24 hours. Sperms in the female reproductive
tract swim under their own steam - as a result of the whip- like activity
of their tail which propels them on. Of the millions of sperms released
in an ejaculate, only a few hundred will make the arduous trip upto the
egg successfully. Perhaps this is why so many millions of sperms are produced
in the first place even though only one is needed to fertilise the egg
- because the wastage is so prodigal.
How does the egg reach the tube?
When ovulation occurs, the mature egg is released from the follicle in
the ovary. This process of follicular rupture looks a bit like a small
volcano erupting on the ovarian surface. At this time, the tubal fimbria,
like tentacles, sweep over the surface of the ovary, and actually " swallow"
the egg. The egg has a shell, called the zona pellucida, which looks like
the ring around Saturn. It is surrounded by a cluster of nest cells called
the corona cells which serve to nurture the egg. They form the cumulus
oophorus which is a sticky gel which protects the egg and also helps the
beating of the hair-like cilia of the fallopian tube to propel the egg
towards the uterus - like a conveyor-belt. The egg must now wait in the
protective confines of the fallopian tube, for a sperm to swim up and reach
it.
Name:
Parth
Country: India
The journey of sperms inside the female reproductive tract seems like a magic. Millions of sperms are released but only one is able to fertilize the egg. Truly a remarkable process.
Name:
Tusha
Country: India
Never knew about the complex process of fertilization. This article explains in simple language about what happens to sperm and egg after their release.
Name:
Rikki
Country: India
this is an excellent article explaining about the process of fertilization in layman language which everybody is able to understand.
