Two biology questions

[BellaBear]

Are there any biology teachers/doctors/people who know a lot generally who can help? It is only curiosity really - and I wish I had asked more when studying this at school!

1. In all the pictures of wombs from textbooks and pregnancy books there is a void in the middle which contrary to my assumptions (without really thinking about it all) can't be air - sperm and eggs can't fly and anyway it would be really icky to have a pocket of air inside your womb. (It wasn't until I started thinking about it that the physics of the situation struck me) So what is it? Some unspecified mucusy gak?
   
   
2. When a sperm infiltates an egg does your body know in some way? Or does the body not think it is pregnant until the fertilised egg implants? I promise I am not asking this as another way of sympton spotting/alleviating the 2ww, I am just curious in a biology sense. Is some message sent out once fertilisation occurs?
   
   Thank you in advance if anyone can answer these questions!

[CadburyCremeSquonk]

dp (science teacher extraordinaire) says:

1. It is a closed sac, so not really full of anything, the diagrams always show it open, but it is in fact closed.
   
   
2. The body does not know it is pregnant until the egg implants
   
   
   hope this helps

[BellaBear]

So the lining just meets up with the lining on the other side?

Thank you (both) very much! (I've been puzzling over these!)

[PinkElephant]

Hi Bella
Maybe this will help:
www.babycentre.co.uk/preconception/activelytrying/howbabiesaremade/

[BellaBear]

Thanks PinkElephant!

(it was mainly the weirdy 'what is that space in the diagrams' question that was keeping me puzzling - but I was also curious about the whole 'can there be any symptoms early on' quandry)

[MrsMcJnr]

Great questions! and answers, I did not know that!

[laksa]

its a bit like the vagina, that is always shown in diagrams as an open cavity but it isn't!

[BellaBear]

aha!

I love this website, there is always someone who knows the answer!

So no air anywhere??!!! (its not that I actively thought there was, it just struck me in the bath one night that it couldn't be!)