Today is Easter Sunday and my thoughts have turned to eggs. Not the ones made of chocolatey goodness but the ones within my ovaries.
Oh Human wondrous Eggs of mine, when I was just a fetus I had 7million of you just chilling out in my ovaries. By the time I was born you had dropped to one million strong, by the time I hit puberty further decimation in your numbers had occurred and I only had a few hundred thousand left. :(
but still more than enough for a football team.
Once my menstrual cycle kicked in every month approximately 50 of my eggs are recruited to develop but the rest become atretic and die at different stages and only one (sometimes two rarely more) would ever actually be ovulated (thus losing more eggs in great numbers every month).
The one super ‘head of pinsized’ egg that makes it that month, will burst forth from its follicle and be wafted by the cilia of the fallopian tube, towards any hopefully waiting sperm for possible fertilisation. In absence of any sperm the egg will waft on dejectedly and be lost. The collapsing deteriorating follicle (that the egg burst out of) will send a signal for the womb lining to be shed in the absence of fertilisation. Eggs are only viable for 24 maximum 48hours after ovulation before they die (but sperm can live for several days inside the female reproductive tract) therefore it’s a blimming miracle when all things align so they do get fertilised. Especially awesome that a few hundred sperm will really batter the exterior of the egg (see pic!) and as soon as one makes it through the entire surface of the egg changes so no more can make it through. Totally and completely and utterly amazing!
Only 400 eggs or so will ever be ovulated in a lifetime, fewer if you spend a long time on the pill or breastfeeding, and sadly eggs have a use by date and their quality declines dramatically after the age of 35 before finally ovulation ceases for good at average age of 52 (in UK) (in comparison to “cheap as chips” sperm where millions can be produced everyday from puberty until old age (although quality may decrease).
I’m totally completely and utterly in awe of reproduction and the science behind it. Yes I would definitely say there is a miracle of life but it’s not a religious miracle but a scientific one, and so today I am mostly celebrating Eggs and my remaining ones
and eating too much chocolate – after all Easter is often linked to Spring Fecundity, and who knows maybe one day, one of my remaining eggs (I’m estimating 200 oddish will be left to ovulate- Yikes!) will turn into another Curd Offspring. But maybe not as Lord Curd is putting his foot down!
Here endeth your Easter Science Lesson.
Happy Eggtastic Easter
P.S This post dates from my knowledge studying reproductive physiology at University 8years ago. Of course science has moved on in that time and I completely forgot that last month research was published that indicated human female eggs may not be finite in number after all (see here) which is also groovy and amazing stuff.