Microcytic anemia | Hematologic System Diseases | NCLEX-RN | Khan Academy

– [Voiceover] Have you
ever tried to memorize all of the different types of anemias? If you have you know that that’s a really, really hard thing to do. And that’s because there are lots of different types of anemias. So to make the job a
little bit easier for us, what they’ve done is they’ve split up all of the different types of anemias into three large categories. So just to catch up everybody to speed, anemia refers to when you
have too few red blood cells. Too few red blood cells in the body. And like I said, there are
three large groups of anemias. The first group. First group of anemias is
called the microcytic anemias. The second group is
called normocytic anemias. And the third group, the
final group is called macrocytic anemias. And these three groups are split up according to the size
of the red blood cell. So what do I mean by that? Well in microcytic anemia,
you have micro, small, cytic cells. So you have small cells. Small red blood cells. Well how small is small? A normal red blood cell is anywhere between 80 to 100 micrometers cubed. So in microcytic anemia, you end up with red blood cells that are less than 80 micrometers cubed. The second group is a normocytic anemia. So normo means normal, cytic means cell. So these are red blood cells
that are normal in size. So their size ranges anywhere between 80 to 100 micrometers cubed, okay? And finally, you have macrocytic anemia. So macro means large, cytic means cell so you have large red blood cells in this type of anemia. So these red blood cells are greater than 100 micrometers cubed. So these anemias are split up according to the size of the red blood cells. And it turns out that that has a lot to do with the cause of the anemia. With the underlying cause of the anemia. In this video, we’re gonna talk about the microcytic anemia. So these guys right here. And I’m just gonna go ahead
and put it all out there. I’m gonna tell you that
all microcytic anemias, all of them are due to a problem. They’re due to a problem in making, making hemoglobin, okay? So all microcytic anemias
are due to a problem in making hemoglobin. And I guess I can’t just say that. I should explain it a little bit, right? So let’s start from the very beginning. What is hemoglobin? Well we do know that red blood cells, red blood cells are full of hemoglobin. Are full of hemoglobin. Okay and I know I’m spelling
that a little funny. So red blood cells are full of hemoglobin and hemoglobin is actually
what binds to the oxygen. So it’s what gives a red blood cell the ability or the
capacity to carry oxygen. So what is hemoglobin? Well I spelled it a little funny here to show you that hemoglobin
has two main components. Two sub units, the first is heme. And the second as you may have guessed it is called globin. And globin is a polypeptide. So what that means is it’s
a chain of amino acids. And this chain isn’t big enough or it isn’t complex enough
to be called a protein so it’s called a polypeptide. And globin comes in two flavors inside hemoglobin. So there are two flavors of globin. The first is alphaglobin. And the second is called betaglobin. So these are the two main
types of globin molecules inside hemoglobin. So the second component
of hemoglobin is heme. And that itself has two sub units. Or two components. The first is protoporpherin. This is a picture of protoporpherin. And you can tell that it’s
a really complex molecule and it has this ring shape. It has this ring shape. And in the center there’s this space. And that space is reserved
for the second component of heme, which is iron. So in this space you’re
gonna find iron, okay? So in a nutshell that is
the structure of hemoglobin, the different sub units to hemoglobin. But what does any of this have to do with binding oxygen? We said that hemoglobin
is what binds the oxygen so where’s the oxygen in this picture? Well it’s actually found over
here bound to the iron, okay? So iron serves a really,
really important role in not only the structure
but also the function of hemoglobin. So like I said, microcytic anemias, all the microcytic anemias
are due to a problem in making hemoglobin. So what are some of the different ways in which you could end up with a problem in making hemoglobin? Well let’s start from the bottom with the globin molecules. So if you had a problem
with making globin, right? That would lead to a problem
in making hemoglobin. And when we have a problem
in making hemoglobin we end up with microcytic anemia. So those group of diseases in which you have a problem in making hemoglobin tend to be hereditary. They tend to be genetic. And they’re referred to
as the thalassemians. So these are a group of microcytic anemias in which you have due to a
problem in making globin. Well moving up, what if we had a shortage of iron in the body? Okay. That would lead to a
problem in making heme and hence a problem in making hemoglobin leading to microcytic anemia. Well that disease in which
you have a shortage in iron leading to microcytic anemia is called iron deficiency anemia. I know very clever name, right? So iron deficiency anemia. Another very similar disease
is anemia of chronic disease. And this is a type of
microcytic anemia once again in which the body has enough iron, but for some reason or another, the red blood cells aren’t
able to access that iron to make hemoglobin. And so you end up with
a microcytic anemia. Finally, if the body had a difficult time making protoporpherin,
that would once again lead to a problem in making hemoglobin, subsequently causing a microcytic anemia. And that disease in
which you have a problem in making protoporpherin is called cyteroblastic anemia. So these are different
types of microcytic anemia. And we’re gonna flesh out the details of these different
anemias in later videos. But for right now it’s good to know the different ways in
which you could end up with a problem in making hemoglobin. So I guess the one thing
I really haven’t adressed to this point is why is it when you have a problem in making hemoglobin you end up with a microcytic anemia? Or an anemia where you have
really small red blood cells. Well to explain that I’m gonna draw a normal red blood cell. And let’s say this normal red blood cell has I don’t know let’s pick
a random number like six. Let’s say it has six hemoglobin molecules. So that’s three, four,
five, and six, okay? In a microcytic anemia, we would end up with a red blood cell that has too few hemoglobin molecules, right? Because we have a problem
in making hemoglobin. So let’s say instead of six we have four. Three, four hemoglobin molecules, okay? Well the body looks at this red blood cell and says that’s a problem. We can’t have that. We can’t have this big old red blood cell with too few hemoglobin
molecules inside it. And it says that if we can’t have a good number of hemoglobin molecules inside each red blood cell, we should at least, at the very least try to get the concentration
of hemoglobin molecules inside the red blood
cells as close to normal as we can. And it does this by
allowing the red blood cells to undergo essentially an
extra, an extra division. Extra division. And this isn’t exactly what happens but it’s a really good
way of thinking of it. So the red blood cell
undergoes this extra division and you end up with two
smaller red blood cells and each of them is gonna have two hemoglobin molecules inside. So as you can see from this picture, you end up with small red blood cells and each of those red blood cells has a fewer number of
hemoglobin molecules inside. But as you can imagine, the concentration of hemoglobin inside these cells, because the cells are
smaller, is closer to normal than with the cell over here. And so that’s why, when you
have a problem in making hemoglobin, you end up with a microcytic. A microcytic anemia. Or an anemia in which the red blood cells are much smaller than normal, okay? And like we discussed, these
are the different types of microcytic anemia. The different ways in which you can end up with a
problem in making hemoglobin.

40 Replies to “Microcytic anemia | Hematologic System Diseases | NCLEX-RN | Khan Academy”

  1. good presentation but too your other vids are too scattered, please do one presentation  for macro, one for norm and one for micro, and then one just for destruction anemias.

  2. Anaemia, as defined by WHO, is not too few RBCs but rather a reduction of haemoglobin below normal ranges for the individual. Other than that this is a very useful revision tool 🙂

  3. Great videos on anaemia… Thank you so much for making things easier… Please upload one on Macrocytic anemia and one on Normoytic… That will really be helpful.

  4. Thank you so much for the video. I'd really understood well. Can I know whether there's videos on microcytic anemia and normocytic anemia?

  5. well defined about microcytic anemia! but I confuse about the term abbreviation for hemoglobin whether is it Hb or Hg. thanks

  6. Lead causes sideroblastic anemia at the same time increases the level of protoporphyrin. In the video you mentioned "if the body has difficult time making protoporphyrin, it results in sideroblastic anemia". can you please explain this

  7. You mentioned of RBCs undergoes an “extra division”. Will you please tell me in a molecular basis on how was this possible?

  8. ?i have a question, first of all, why a small RBC it's a problem for the patient
    ?and the second question if we do the extra division so why we end up with a lesser RBC

  9. Great video on anemia thank you very much. May i ask u a question:
    You said microcytic anemia is all about a problem in making hemoglobin; so my question is how a sideroblastic anemia could be a problem in making a protoporphyrin part..? Please make it clear for me beacause my teacher told me that it's a condition that the body has enough iron but the cell can't use that iron so im confused plse help me.

  10. Simply excellent. Very grateful for clear, concise and well presented video. Thank you for the great channel. 13/8/2018 😊

  11. In book it is given that protein deficiency leads to hypochromic "macrocytic" anemia.
    It shouldn't be microcytic instead of macrocytic

  12. Very very good presentation 👏🏼 I’ve always mixed them up 😅 But I’ve really understood it all .. Thank youu for your efforts and good teaching 💓

  13. 7:38
    one RBC can have only four hemoglobins. Not six!!
    And Hemoglobin is Hb, not Hg
    Good video though!!!

  14. please don't say everything twice…."the first is heme, the first is hemoglobin"…"the thala, the thalassemias, the thalassemias" ….otherwise good job

  15. Everything is good except for the fact that u keep on saying the same thing twice over.. It gets to ur nerves as we keep on listening.. So kindly avoid that.. Otherwise very good presentation made evrything so simple

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