That’s a great little diagram! I think I know what I’LL be next Halloween! I’m dreaming of the cape now 
I dunno. It depends on if the cervix is n/o or n/c.
Which is it, by the way? It feels closed if you bump it. (Owww, huh?)
All these years (I’m in my 50s) and I never really knew that the eggs and the fallopian tubes are not directly connected. It’s hard to tell from an instructional diagram, but when you say “they’re right next to the ovary”, how close is that? An inch? More? Or more like fractions of an inch?
In theory it could, but that doesn’t happen to my knowledge. We’re upright creatures, so most of the time any extra fluid would be down by where the cervix attaches to the outside, not up where the tubes open. And the tubes themselves are pretty narrow and tortuous. Not the kind of thing that is conducive to fluid just flowing out.
Algernon I haven’t dissected a human, but from looking at animal rigs and diagrams and spending way way too much time talking about reproduction, my understanding is that the edges of the fallopian tube are close enough to the ovary to be brushing over its surface. Honestly, the fact that we can reproduce at all is really amazing.
mangeorgeThe cervix is only closed during pregnancy (or pseudopregnancy in dogs, but that’s another topic). But, the opening through it is fairly small, even in large animals. A cow’s cervix is about as wide as a garden hose, but the opening through the cervix is only maybe 3 millimeters in diameter.
When you combine that information with the knowledge that the bull is an interuterine ejaculator, the idea of just bumping the outside of the cervix doesn’t seem nearly as painful. :eek:
Ok I have dissected a human, and been at enough hysterectomies, gynaecological laparoscopies and c-sections to feel able to comment, but bear with me, because I’ve been at work for the last 28hours straight.
First up mks57- intra-abdominal fluid doesn’t leak out via the vagina, having tracked down from the fallopian tubes, even when the intra-abdominal pressure is immense. Women with liver disease or ovarian cancer can often have litres of fluid sitting within the abdomen. It unfortunately doesn’t leak out vaginally and often has to be removed with a large needle through the abdominal wall.
Think of the fallopian tube as like a piece of really over-cooked macaroni- it sits closed and is quite difficult to get open. It’s not like a raw or half-cooked macaroni where you could imagine it working like a little straw.
SharkB8 The “ligaments” holding the pelvic organs in place are generally speaking not true ligaments like the ones in your knee, but are simply folded layers of the peritoneum and fascia- i.e. not very strong and not very supportive. That is why a lot of ladies suffer from prolapse, especially after childbirth.
Pullet The human peritoneum might be slightly thicker than you realise. The parietal peritoneum is visible as a whiteish sheet, although the visceral peritoneum is much thinner (it looks a bit like clingfilm/Saran wrap).
While the uterus and part of the bladder are covered by parietal peritoneum, and so are separated from the intestines, the fallopian tubes and ovaries aren’t and so are in the same cavity as the intestines. At laparoscopy dye that is injected through the cervix to test for tubal patency will pool in the pouch of Douglas (the bit at the bottom between the vagina and the rectum, the rectouterine pouch), and if a laparoscopy is done during menstruation you can often see menstrual blood sitting there too.
This image of a dissection specimen (with the bowel removed) might help people visualise things 3D (not for the squeamish).
This image might be helpful too. It is a cross-sectional diagram and is much less gruesome. The blue-ish areas are those contained within the abdominal peritoneum, as you can see the uterus is separate from the bowel, but the fallopian tubes and ovaries are within the peritoneum with the intestines.
The ovaries are each about the size of the first joint of your thumb, the fallopian tubes about the length of your thumb. The fimbriae (fringed outer ends) of the fallopian tubes touch the ovary or lie just above or beside it. The non-pregnant uterus is about the size of a small avocado.
When doing a c-section, we cut into the lower segment, this is the part of the uterus that is still covered by peritoneum, and if you look at a diagram you’ll see that the bladder has to be very carefully moved down and out of the way to avoid cutting it. We look for the white line that shows the end of the parietal peritoneum and sometimes it can be hard to see.
Hope this was helpful.
Excellent post, Irishgirl!
I figured there were species differences that I wasn’t aware of. But yeah, same idea. The paritoneum isn’t a discrete sac that you could pick up with your fingers like the pericardium.
Maybe you can answer a hijack: Why oh why do human ultrasonographers want your bladder to be full to bursting when doing a pregnancy evaluation? If I can find the walnut sized bladder on an angry cat and tell it apart from a gravid uterus, why can’t they?? :mad:
Thanks, irishgirl, for the excellent info. Especially the size comparisons.
And, of course, the “Pouch of Douglas”. 
Pullet- possibly because your cat won’t want a perfect picture to take home in it’s wallet?
Personally I don’t think it matters much except between weeks 4 and 6, but then I was not hesitant about asking to do a transvaginal scan if I couldn’t see what I needed to, and some of our ultrasonographers are.
I scanned whoever turned up in whatever state they turned up, and usually I could see a foetal heart in the right place without much effort after 6 weeks in an averagely built woman.
Sometimes though that sac is damn tricky to find and you have to go TV or ask her to drink something just to get the differentiation between fat, fluid and tissue that you need. Being smaller, your ultrasound waves have less tissue to go through in the felines, and that should make life easier for you, but then, my patient didn’t usually bite or scratch me, so it’s swings and roundabouts.
Ok, I guess I can begrudgingly forgive the human doctors then, for the sake of good pics 
I guess there’s no winning, no matter the species. The thicker ones, like cows and horses, get trans-rectal ultrasound, often with the hand up the rectum in order to get the probe over the uterus :o
Johnny Knoxville, is that you?
irishgirl, how does menstrual blood get outside the uterus and into the pouch?? I don’t understand this.
What I cannot comprehend is how the egg gets into the fallopian tubes!! Ok - the egg has no motility, so how does it make the transfer into the tube, and not into the abdomen? You said the fallopian tube is like “over-cooked macaroni- it sits closed and is quite difficult to get open” – so if it’s so narrow how does the egg make it? Does the tube offer some sort of suction that draws the egg into it? And does the tube somehow inch or squeeze the egg along into the uterus? And what part do the fimbriae (fringes) play in getting the egg into the tube - do the “fringes” sweep or somehow direct the egg into the tube? 
Well I may have figured this part out – I found this on the link you provided ( http://www.endo-clinic.co.uk/aboutendo.htm ):
That is wild - I had no idea it could do that… What I don’t get is if there is really no barrier between your insides (your abdominal cavity) and your outsides – in other words, an unobstructed straight shot – via your vagina > uterus > fallopian tubes > abdominal cavity – why is it that bacteria can’t easily make the journey and infect our insides more easily?
I’m not sure if the fimbriae actually move under their own power, but your organs shift around inside you as you go about your daily activities, swinging about in response to gravity. That would be enough motion for the fimbraie to sweep the surface of the ovary and scoop up the egg.
The fallopian tubes are lined with cilia, microscopic hair-like things that stick out from the cells that line the tube. The cilia move in unison to sweep the egg down towards the uterus. The airways of your lungs are also lined with cilia, which sweep upwards to carry dirt out towards your mouth.
And the egg is really tiny. Yeah, it’s big for a cell, but cells are tiny.
Now how dose a chicken ovulate a whole yolk into the open end of its fallopian tube without dropping all of them, there’s a question! 
I just realized how incredibly rude it is for me to scoop up a direct question to Irishgirl. Sorry. Will go back to lurking now.
No don’t apologize! I’m glad you answered - that way I can go to bed without this mystery weighing on my mind! Although I still can’t believe that the egg can make it into the tube so (seemingly) effortlessly.
So does this mean that sperm are swimming around inside one’s abdominal cavity? As is, they just keep swimming, all the way through the uterus, through the tubes, and out into the cavity? What if they manage to fertilize an egg that is just coming out of the ovary, but hasn’t separated yet? (I know that intra-abdominal pregnancies were mentioned above, but still?!!) Or do the cilia in the tube only sweep one way, and therefore sweep any adventurous sperm back down?
Inquiring minds want to know…
Ok fine! But only because I think Irishgirl might forgive me and because this question is too fun to pass up.
Short answer: Yeah, sperm can swim all the way up and fall into the abdominal cavity. That’s how those abdominal pregnancies happen.
However, the number of sperm that make it that far in the first place are comparatively few, and they all die in a couple days after ejaculation, so no worries there. Your body just cleans them up.
The egg isn’t just sitting on the outside of the ovary, waiting to fall off. Here’s a diagram. Look at the piece labeled “oocyte” in the diagram at the top of the page. See how it’s in that fluid filled bubble? Now look at the bottom of the page. That cross section is a close up of the mature egg sitting inside its fluid filled cyst, waiting to be ovulated. See all the layers of cells surrounding the cyst? A sperm would have to make it through all of that in order to fertilize the egg.
Furthermore, a freshly ovulated egg isn’t quite ready to be fertilized yet (at least in dogs. Irishgirl, smack me down if I get this bit wrong) A newly ovulated egg hasn’t quite finished dividing its genome down to the required 1/2. At the time of ovulation, it actually has twice the number of chromosomes as other body cells. After it is ovulated, it divides and spits out half of those chromosomes into a little chuck called a polar body. Now the egg has the same number of chromosomes as other body cells. Right after the egg is fertilized (literally in seconds), it spits out half of its remaining chromosomes again, making another polar body, and bringing its chromosome count down to 1/2 that of normal body cells. The chromosomes from the sperm move in, making a whole new cell with the correct number of chromosomes.
See what I mean when I say that it’s amazing anything reproduces at all?
Pullet thank you! I love this stuff, it’s so fascinating. This is why I love the Dope! That’s a great and helpful diagram.
It IS amazing anything manages to reproduce! What is even more amazing is that in humans, we still manage to get pregnant despite efforts not to - in my case I got pregnant twice in one year while on the pill! I still can’t understand how that happened! (I mean I know, I just can’t believe I beat the odd twice despite being so careful!)
Which brings me to another question/comment - I still can’t fathom the fact that infant girls are born with all their eggs… and they just sit there for years in the ovaries waiting to mature and be ovulated. It just amazing when you think of how much time and opportunity there is for those cells to get damaged over the years (and yes I realize they do - as each year goes by I realize that the chances of genetic defects goes up as I get older.)
p.s. Pullet, I take it you’re a veterinarian?
Almost. A little more than a year and I’ll be a full grown-up. After only 8 years of education! :smack:
I love the Dope for this kind of stuff, too. In one thread I can ask stupid basic question about car care and get sincere answers, and in another thread I can be reminded where all that student loan money went.
Can that trigger immune system response?
It totally blew my mind one day when I was pregnant and I realized that, in a sense, I was also creating and *carrying *my potential grandchildren. All those eggs, already formed, and before my daughter was even born! :eek: