Congrats, You are the Winner...

...of The Great Sperm Race;

Probably the most enduring and stamina-demanding race existing on earth...or may be the universe..!! Why? Look at the facts below and you would know, why you should feel good that you were born.

Of the approximately 250 million human sperm cells that enter the vagina just a few thousand are able to enter the fallopian tubes and just one, that's you, will fertilize the egg.

There are many obstacles that sperm must overcome to reach their destination.These include:

The acidic atmosphere of the Vagina.
The vagina is an open tract and thus is vulnerable to infection from outside. As a consequence, it is well equipped with antimicrobial defenses including an acidic pH of 5 or under which is microbicidal to many sexually transmitted disease pathogens. The pH of semen plasma is around 7 and has the potential to neutralize vaginal acid.

Did you know your vaginal pH rises from 4.3 to 7.2 within 8 seconds of the arrival of semen. Case is different when your partner uses a condom, otherwise the high pH might just affect the condom durability.

The mucus of the Cervix.
When the sperms enter the cervix, it secretes highly hydrated mucus, often exceeding 96% water. Research has also shown that higher water content correlates with occurrence of pregnancy! The hydrated mucus creates a barrier, stopping the microbes and sperm with weird mobility.. which means not-good-sperms!!

The narrowness of the Uterotubal junction (the entrance to the Cervix).

The white blood cells of the immune system, which see the sperm as a pathogenic ‘foreign invader’ to destroy.

‘Kamikaze’ sperm hypothesis
According to some research, the million sperms coming out of one ejaculation, might be divided in 3 groups- egg-getters, blockers and killers. For this, the sperms have to have a self-recognition system, which the sperms being single-body entity is quite a bleak possibility...

You might not be knowing, your sperms might of 2 types: One coated with IgG and One without it.. The ones without the IgG, are also called the 'Rapid-Transport Sperms'. Just reaching before the cervix, the white blood cells attack the sperm population. Now the one with the IgG coating are the one who face these preventive measure and sacrifice themselves for their brother sperms. These coated sperms also get entangled in the mucus of the cervix and let the uncoated ones pass through...

The Other Man

Sperm competition theory suggests that rival male sperm samples might behave neutrally with respect to each other in vivo. Our own conclusion is that sperm ‘compete’ against any sperm, be they from their own ‘group’ or another. Their ability to reach and fertilize the egg is a factor of their own design and build – their ability to do everything correctly that is required en route through the female tract – and critically their timing at every stage. So if all else is equal in design and build terms, the successful spermatozoon is the one that is in exactly the right place at the right time, at each stage on this extraordinary journey.

The human uterine cavity is a few cms in length and could be traveled in less than 10 minutes by sperm swimming at about 5 mm/min, which is the swimming rate of sperm in any liquid medium.

Is there a Sperm Reservoir in the Fallopian Tube?

Since pregnancy has been shown to result from intercourse as long as five days before ovulation, human sperm must be stored somewhere in the female tract. There is strong evidence that such a reservoir is created when sperm bind themselves to the inside(epithelium) lining the tube. This prevents multiple fertilization and saves women from having twins/triplets every time.

Now, Ladies your turn.
A woman usually ovulates one oocyte (egg) each month, so that makes about 400 in your entire reproductive lifetime..Your eggs are also surrounded with some membrane that helps to select the good sperms, around 10-20 for the final penetration...

Now it's a lot of acid, zigzag pathways and bit of luck!!

Imagine, a twirling bath of 5000 cells, acid, and the 10 possible suitors. The Egg is slowly shedding her skin, and so are the 10 guys..Orgy? NO!! Multiple fusion occur and each remaining sperm attaches his head to the egg.. The female egg slowly preps an opening and only one sperms can enter the egg and activate it... As soon as one sperm is chosen, the egg changes itself and rest of the sperms get detached!! Now the egg with the sperm inside gets attached to the inside surface and waits!!

Old is really Gold!!

Did you know, in 1938, sperm count in a healthy male was 113 milllion/ml, which sharply and sadly declined to 66 million/ml in 1990.

A large study of Denmark, Finland, France and Scotland showed that Finnish men were found to have higher sperm counts than the others. A common feature in the decline of sperm concentrations is its association with year of birth: younger cohorts have lower sperm concentrations than the older generations. The lowest sperm counts were found in 18–19 year old Danish men in 1997–8. The median sperm concentration was 41 million/ml and 18% had concentrations below 20 million/ml which is considered a threshold for sub-fertility (by the World Health Organization.)

A study of maternal smoking in relation to semen quality reported lower sperm density and also exposure to phthalates, commonly used in plastics, now a days.

Wriggle your sperm all the way up the fallopian tubes to success! Play the Great Sperm Race Again!!