- [Instructor] Blood typing is all about
how an antigen and antibody interact.
Well, first off, what is an antigen?
An antigen is a marker on the cell's surface.
An antibody, is going to be a particle
that is meant to recognize foreign antigens.
So we have, what are called A and B antigens.
These are for our red blood cells.
When you're blood typing, you ignore the platelets.
Ignore the white blood cells.
The only thing that counts for blood typing
is red blood cell.
So it can either have, an A antigen,
or you could have a B antigen,
or it could have an A and B antigens,
or it could have none on the surface of our blood cell.
It's this combination
that creates our different blood types.
Antibodies, well I already said,
these are going to be different particles.
Basically proteins.
They're meant to detect foreign antigens.
And as A and B antigen mix what is called the ABO system.
Now, that is the most commonly used system
you hear about currently in today's society, ABO.
But it's not the only type.
There are dozens of other types
of blood typing systems out there.
We're only going to deal with the ABO system.
So what is the ABO system?
Probably A positive, or A negative. B positive, B negative,
O positive, O negative, or AB positive and AB negative.
But to get those positives and negatives,
you must combine the ABO system with the Rh system.
Because the Rh antigen is what gives the plus
or minus to blood type.
Let's start here, we have one cell
that is showing type A blood.
One showing type B, one showing type AB, one showing type O.
Well they put these little spiky things on.
I'm gonna call those the A antigens.
So those little triangles are going
to be the cell surface markers
that identify this as a type A blood.
Well, think about those look like they've filled A in.
In reality, no the antigens do not look like triangles.
But, I can't quite show you a three-dimensional view
of this chemical coming out of your screen so
we're compromising.
Triangles and half circles.
The B antigen is going to be a half circle.
This A blood better have this A antigen.
And the B blood, better have this B antigen.
What do you think AB blood is going to have?
Well, if you are thinking it will have A
and B, you're right.
But type O?
Type O will not have any AB antigen.
So we have, A and A antigens, B and B antigens.
AB with A and B antigens.
Then no AB antigens on the surface of O.
Does that mean there are not any antigens on O?
No, there are still antigens just not the A or the B.
So how about this, add up that little kind
of wide-shaped antibody now.
Looks like it fits pretty well on top of the A antigen.
Is that a good thing?
Remember, antibodies are meant to recognize
and whatever they recognize, they destroy.
See, probably don't want to have the A antibody
with the A antigen.
It markets for destruction.
B antibody with B antigen, nah, bad idea.
What ends up happening is,
you get the B antibody with the A antigen.
The B antibody can't recognize it so therefore it's safe.
The A antibody goes with the B antigen.
Again, cannot recognize so it's safe.
O, got everything, AB nothing.
Does that make sense?
Yeah, think about it.
If you have A and you have B antigens,
could either the A or the B actually live there
and not attack it's own cell, no it can't.
There is no AB antibodies.
But on type O blood,
you have the A and the B antibodies.
The reason you have both is there's no antigens.
What we've done here, is that the whole
ABO blood typing system?
Nah, we have to get in plus and minuses.
So let's make AB positive.
If you know it, just add in those two black rectangles.
The rectangles are gonna be the antigen for the Rh factor.
So the Rh factor now gives a positive or plus.
What about the other three?
Well, for simplicity purposes,
we could make them all negative.
If they're negative, that means that
they do not have the Rh antigen.
They do not have that square or rectangular block.
This is just a different way of looking at the
A antigen with the B antibodies.
Or the B antigens with the A antibodies.
Trying to show how they relate,
how they compare to each other.
In the bottom figure, you can notice
those are real blood samples.
Type A, type B, type AB, and type O.
Well, the anti A antibodies, the type A blood
is gonna agglutinate or clump together.
That's because the A antibodies recognize
the type A antigen
but did the B antibodies do anything under type A?
No, they had nothing to react with.
So this the inverse with type B.
The anti A was fine because it interact
with the cells, the body, no problem.
But the anti B was an issue.
Because the anti B now, did agglutinate, or clump up.
Type AB, well if you have type A antibody,
you have type B antibody.
Well they're both there, 'cause they both have antigens.
So put type AB blood and mix it with anti A,
anti B antibodies, it's gonna react.
Both times.
While the type O blood does not react.
Because remember type O does not have the A
or the B antigen.
That means it cannot react with what it does not have.
Hemolytic Disease of the Newborn,
this is only possible if the mother is Rh negative.
So, A negative, B negative, AB negative, O negative.
And the father is going to be Rh positive.
Now the father being Rh positive, could be A positive,
B positive, O positive, AB positive.
Now so only the problem, if the developing infant
ends up being the Rh positive, like the father.
'Cause, during this developing infant,
as long as it's the first one,
during this infant's development the antibodies
really shouldn't mix with the mother and the fetal.
The fetal red blood cells stay on one side of the placenta,
paternal blood cells stay on the other side of the placenta.
So usually, there's not really much mixture here.
Which is a good thing.
But now once childbirth occurs, usually,
a little bit of that infant's blood is going to mix
with Mom's blood.
Whether it be from a tear in the placenta,
a tear in the uterine or vaginal wall,
something is going to cause blood to mix.
Well, once that blood mixes,
that means it's Rh positive, mixing into Rh negative.
What ends up happening is, the foreign Rh
is gonna end up causing an Rh antibody reaction.
These Rh antibodies aren't gonna hurt the Mom
'cause she's already negative.
What it will do is the antibodies will remove any positive.
So all of a sudden maybe, some other different blood type
that was a positive Rh, from the Dad for instance,
that would be removed.
No big deal for the Mom, she can function normally.
The problem is, if that Mom is still Rh negative,
which more often than not, will be,
and a second infant, is developed,
and this infant is also Rh positive.
Well now it happens, those special anti Rh antibodies
can actually cross through the placenta
and get right into the fetal circulation.
Well in fetal circulation you have Rh antibodies,
that can recognize and destroy other parts of the system.
Well, you gotta be careful here
because that could actually cause the entire child
to end up being destroyed from the inside out.
Not a pleasant idea.
Thankfully the simple shot called rhogam can be given
during pregnancy to help block the Rh positive blood cells
from triggering this reaction to make the antibodies.
Anemia really isn't one individual disorder,
it's a family or grouping of disorders.
All the different types of anemia carry one common feature.
They all have a reduction in oxygen-carrying capacity.
Now this reduction in oxygen-carrying capacity
could be because there's not enough red blood cells.
There might not be enough hemoglobin.
Something might be formed the wrong way.
So one type is iron-deficiency anemia.
Iron, who cares about iron?
Remember, iron was in the hemoglobin molecules.
It was for our molecules per hemoglobin
that's where the gas bound.
So there's not enough iron
simply can't have enough binding of oxygen.
Hemorrhagic anemia caused by massive blood loss.
A hemorrhage, a massive cut
and also the blood just pouring out.
I have this massive blood loss,
you can not keep enough oxygen in the system.
Pernicious anemia, it's a vitamin B-12 deficiency.
So not enough vitamin B-12,
you cannot make enough red blood cells.
And hemolytic anemia, in this case, the red blood cells
are being damaged and killed off too quickly.
So it's destruction of the red blood cells.
Leukemia, it's a form of cancer unfortunately.
It's a form of cancer of the white blood cells.
The white blood cells are going to be very numerous,
just the problem is, they're not all functional.
So you have tons and tons and tons
of immature white blood cells.
Means they can't fight.
Mononucleosis.
This is actually a virus called the Epstein-Barr virus.
It's the infection of your lymphocytes.
Well, mononucleosis can be very problem-some
because it caused the person to be very weak, very fatigued.
And recovery can be quick or it can drag on
sometimes for a couple of months.
So, mononucleosis.
Septicemia or blood poisoning.
The bacteria is growing in your blood.
'Cause your blood is warm, dark, nutrient-rich,
so the bacteria just proliferate,
they grow like crazy in here
overwhelming your body's defenses.
And then thrombocytopenia, the platelet number is down.
If you don't have enough platelets,
you have unusual bleeding, unusual bruising.
Because your body cannot clot,
cannot cause the standard reaction.
So thrombocytopenia, reduction in number of platelets.