Now we know what could be harmful to the fetus,
let's talk a little bit more about the developmental process.
Let's look at the placenta. Now the placenta is amazing.
Not like a pizza, a pizza is super amazing but a placenta is pretty amazing, too.
The placenta is the lung, the kidney, and all good things about fetal development.
So let's see what goes on.
Now the first thing that's really unusual is the compilation of the arteries and veins.
So there are actually two arteries and one vein in the umbilical cord
and that comes from the placenta.
You can also find the fetal artery and the vein that are actually scrolling
through the placenta as well.
We have chorionic villi which kind of look like little pieces of liver sort of attached
and inside the chorionic villi we have trophoblast,
remember those from embryonic development?
We're going to talk about genetic screening and one of the genetic screening test we do
is called the chorionic villus sampling and this is where we get it from, the chorionic villi.
It's important to note that maternal and fetal blood do not mix, so it's not a continuous loop.
We have transport that happens in terms of electrolytes in terms of oxygenation and carbon dioxide,
but they don't go together, they're not one system, they're completely separate.
And then if you'll look at the bottom of the placenta you'll see the maternal artery and the vein.
We had the fetal artery and vein on top, and we had the maternal artery and vein on the bottom.
So I want to show you the placenta and see if this helps to make a little more sense.
I know you haven't met Clitus the fetus yet, but here he is and his placenta.
So to give you an idea visually of what this looks like, here is the placenta.
Now this is the maternal side of the placenta and you can see, the baby
actually goes into the sac here, and here's the fetal side.
Here we have all the chorionic villi and the cotyledons here.
We have the umbilical cord that comes off the placenta here.
We have the chorion which makes up the outer layer of the sac,
then we have the amnion that makes up the inner layer, isn't that cool?
So it shows you the amniotic sac. Let's look at it on the graphic.
So within the amniotic sac we have the outermost layer or the chorion,
and we have the innermost layer which is called the amnion.
Okay, so let's talk a little bit more about endometrium formation during pregnancy and the layers.
So we think about the basalis.
Now the basalis eventually will become the placenta, that really cool thing I just showed you.
The capsularis are actually a compilation of cells that form around the gestational sac.
And then the parietalis are group of cells that cover the entire rest of the endometrium.
So think about outside of the gestational sac, we could cover just the sac,
then there's the whole rest of the endometrium where the baby is not
and the cells are actually going to line the rest of the endometrium, okay?
So those are the three parts, that's what's going on in the endometrium.
Now, I want you to have a turn in determining the layers of the endometrium.
Each number represents one of those layers.
Can you match capsularis, basalis, and parietalis to the right number?
Number one is capsularis, number two is parietalis, and number three is basalis.