I think it's unbelievably amazing how spermatozoans work. It's like a friggen game. The sperms have to go through a series of intense trials to get to the egg, you know? So here are their stats:
After ejaculation, the sperm has a time period of 4-6 days to reach their goal, otherwise they die. But, the ovulated egg remains viable for only 24-48 hours. Therefore, the sperm (or rather, the guy) has to time it right.
So the sperms all get released at the same time. Their first goal is to reach the fallopian tube, but some can't even handle the beginning and die from the enzymes secreted from the walls of the vagina/cervix/uterus. Only a few dozen sperm out of the 3 million released survive in the fallopian tube, and in there they have to face a stage called capacitation, where they have to reside for hours in the secretions of the female tract to become capable of fertilizing the egg. THAT'S SO INTENSE, right? They're like resting & honing their skills in the fallopian tube to get ready for the final stage. And then once they're ready they all charge after the egg, but wait, they have to go through another ordeal! Surrounding the egg are cells of the corona radiata and the zona pellucida, so those surviving sperm have to release enzymes from their acrosomes to break down those two barriers to reach the egg. And finally, the first sperm to get to the egg gets to share its DNA! The egg in turn immediately creates an electrical block to prevent any other sperm to get in.
Isn't this amazing?! So much more respect for sperm now. Learning all of this reminds me of the trials in FFX and how in the very end of all the puzzles and random battles with fiends, you get to obtain the aeon. Yeah, I'm studying for finals. ;)
Labels: random, UC Berkeley