Transcription
Welcome everybody. Let's continue our review of hematology/oncology. We are talking now about anemia. There's a playlist where you can watch the previous videos, which I will link in the description. So, erythrocyte indices. What's an erythrocyte? Erythro means red, cyte means cell, and this is, of course, the plural of index. If you do not know that, there is no hope for you.
Let's start with RBC count. Erythrocyte count: the number of red blood cells per unit volume of blood. Imagine that you have like a pool; okay, this pool is full of red blood cells. You count the total, and that's the RBC count. In males, normally you have 4.5 to 6 times 10 to the power 12 per liter, or you can say times 10 to the power 6 per microliter. Okay, so you have kind of 5,000,000 red blood cells per microliter in a male. In a female, it's less: 4 to 5 times 10 to the power 12 per liter.
Next, we have the hemoglobin concentration. Any concentration in physics, there is a rule: the amount equals volume times concentration, so concentration equals amount divided by the volume. Okay. g/dL. We measure the amount in grams and volume in liters or dL. So, in males, that hemoglobin concentration is 14 to 17. What's the measurement unit? Measuring unit: gram per deciliter. Females: 12 to 15. You can remember males as an average of 15 and females an average of, for example, 13.
What else? Hematocrit value. Okay, it's the ratio: volume of RBCs over volume of blood. So we have blood; it has two main components: red blood cells and plasma. The ratio of the red blood cells to the whole blood—now the plasma—the whole blood is the hematocrit. So this—the RBCs—will be kind of 45%, okay, and this will be the 100, and the RBC will be the 45. So 45% is that hematocrit. Normally, males around 45% and females around 40%. Volume of RBCs over volume of blood, not plasma.
Then we have the mean corpuscular volume. Corpuscle means curved body or a cell. So the mean corpuscular volume is the volume, or the average volume of the cell, the red blood cell. So it's the average volume. A small cell will give us a low MCV; a large cell will give us a high MCV. That's a no-brainer. Normal MCV is 80 to 100 fL. So let's say that we have a small cell; it will be what? Low MCV. Large cell? High MCV. That's why we have low MCV microcytic anemia; high MCV macrocytic anemia.
Now let's talk about others: mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. First, the MCH. It's the average content or weight of hemoglobin per red cell. This is the red cell; this is the hemoglobin. Okay, weight of the hemoglobin over the RBCs. So it's the hemoglobin mass or weight or content over the RBC count. Let's say that hemoglobin, we said normally around 15 for males and RBC count, let's say five million, okay, or five times ten to the power of 12, okay, as we said before. 15 over five times ten is 30. 30 what? We call them picograms. That's it. Okay. So hemoglobin mass over RBC count. Mean corpuscular hemoglobin concentration is different. It's the average content of hemoglobin, not per red cell, no, per a volume of blood that has red blood cells. So let's say that I gave you a test tube that has a certain volume of red blood cells. Okay, what's the weight? What's the mass of hemoglobin inside the whole volume, not inside an individual red blood cell. So it's hemoglobin mass over RBC volume, not count, volume. And if you're good at physics, mass over volume is called, yes, density. Okay. So MCHC: hemoglobin to measure or to calculate it, who is an equation? Hemoglobin over the hematocrit, because the RBC volume, okay, with respect to the plasma volume, is called hematocrit times 100. We get 15, the normal hemoglobin, over 45, the normal hematocrit. We get 1/3 times 100 is around 33 grams per deciliter. So the normal MCH is around 30; the normal MCHC is around 33. They're very close. You can remember 30 or 32 and you'll be good.
But I'm still confused. Let's take an analogy: the tale of the tube in the river water. Okay, so we love swimming; we use tubes in the beginning. So imagine that we have a tube filled with air floating in water. So the RBC count will be how many tubes are there? Number of tubes per unit volume of water. That's the RBC count. Okay. Hemoglobin concentration is different. It's the weight of air inside the tubes per unit volume of water. Hematocrit is the volume of the tubes, okay, not the weight, the volume of tubes, which is the same as the volume of air inside the tubes per unit volume of water. MCV will be the average size of tube. Okay, is this tube large? High MCV. Or small? Low MCV. MCH is the average weight of air in every tube. MCHC, we sense the average density of air in every tube.
These are the erythrocyte indices. Hope it helps. Please subscribe; there are new videos coming every week. We are talking about hematology subjects, so please subscribe and watch the whole playlist. Thank you very much.