Transcription
It's Medicos is Perfection Alice. Here we are. Done with anemia. We are going to discuss leukemia. In the previous video, we have talked about the complete blood count. Today, let's talk about the white blood cells in an introduction to leukemia and lymphoma. Coming up, Medicos is Perfection Alice.
But first, what is the function of your white blood cell? It's the military. It defends your body against foreign invaders. If they went nuts and starting attacking your own body, this is an autoimmune disease. If they went nuts and started dividing repeatedly, excessively, in a crazy way, this is called cancer, such as leukemia or lymphoma.
Here are your white blood cells. You have neutrophil, which is neutral. Base of fill with basophilic granules. A us NFL with Ilse no ferric granules. We call all of these together granulocytes. Here we have the agranulocytes. No granules. Magnet shaped. Magnet horseshoe. Monocytes. This is your lymphocyte with very little rim of the cytoplasm left. You cannot differentiate between B lymphocytes and T lymphocytes on the peripheral smear. It's impossible. That's why we need something called flow cytometry, as we will discuss later.
Or learning about any topic for the first time. What's the first question? What's the definition of white blood cells? They are cells. Oh, really? Oh, okay. That's uh, that was nice. Spoiler alert. They are blood cells that are part of the immune system that defends your body against foreign invaders. That's fine. They are nucleated, unlike red blood cells, which were anucleated, unlike platelets, which are not even cells. Platelets are just fragments of the cytoplasm of their parent called megakaryocyte. White blood cells are derived from stem cells called multipotent stem cells. This is their type. This multipotent hematopoietic stem cells will give you the myeloid lineage and the lymphoid lineage. Myeloid include the red blood cells, the platelets, and some white blood cells, such as neutrophils, basophils, eosinophils, and the monocyte. And the lymphoid include the B lymphocyte and the T lymphocyte. Say no distinction by the naked eye using microscopy. That's why we need flow cytometry. Okay. These are the granulocytes. These are the non-granulocytes.
Now, if you understand this slide, you will surf through the sea of Leukemia and Lymphoma seamlessly. So please pay attention. Leukocytes. Luko means white. Cytes means cells. Some people write it with a K, some use a C. I don't care. Okay. Leukocytes. Where can you find white blood cells? You can find them in the blood and in the lymph. What is the blood and what's the lymph? That's easy. They are part of your circulatory system. The blood system is a closed system. It starts in the heart and it ends in the heart. So let's do it from the right side of the heart comes deoxygenated blood to the lung. The lung oxygenates this blood using oxygen that you breathe and returns nice red oxygenated blood to your left side of the heart. Pump it through the aorta to the rest of your body. And then the rest of your body uses blood, uses oxygen, and produces CO2, goes to the superior and inferior vena cava to the right side of your heart. Welcome back home. Starts in the heart, ends in the heart. Closed system. That's blah.
How about the lymphatic system? It's not a closed system. Which means they start at the capillary interface. As your blood is getting filtered through these capillaries, the cells will stay behind and the plasma will diffuse. When the plasma tries to come back, some of them, or let's say the huge bulk goes through the vein or the venule. And a minority of this plasma gets filtered into the lymphatic system. The lymphatic system, again, same reason. They fight infection. They find foreigners. But they have military bases where there are a lot of the army, a lot of the Navy, a lot of the soldiers there to fight infection. These are called lymph nodes. That's fine. So if you have abnormal white blood cells in your blood, this is leukemia. Abnormal red blood cells in your lymph nodes, this is lymphoma. Period. End of issue.
Okay. Now, where is the factory that produces your blood? It's called the bone marrow. That's why leukemia will be in the bone marrow and in the blood smear. So how to diagnose it? Again, get a peripheral smear and get a bone marrow biopsy. How to diagnose lymphoma? You need a lymph node biopsy. We are done. If you understand this, you get the whole concept clearly. It's an oversimplification, but I'd like you to get a grasp of the basis because some students go mad without knowing the basis. Oh, I'm confused. What's the difference between acute lymphocytic leukemia and non-Burkitt's lymphoma? Hey, honey, calm down. Understand the basics first. Goodness gracious. Leukemia in the bone marrow and in the bloodstream. Lymphoma in the lymph node. Okay, fine.
Now, let's take a blood sample and do centrifugation. Okay. Red blood cells are the heavier, the highest density, so they go to the bottom. Okay. If we remember anything about physics, RBCs are 45% of the whole blood. Okay. That's why your hematocrit was 45%. Hello. Okay. The plasma is lighter, less density, it goes to the top. 55%. Now, there is a very teeny tiny, tiny, less than 1% here called the buffy coat. It contains both the white blood cells and the platelets. Okay. That's why we called white blood cells, white blood cells, because they appear white. Okay. Here now, sometimes this layer appears green. Why? What are the most numerous white blood cells? The neutrophils. What do they have in them? The myeloperoxidase enzyme. Oh, that's why they're green.
Okay. Talked about the CBC in the previous video. We want to know the white blood cells, the platelets, and the red blood cells. If you order a peripheral blood smear, you use a stain called Romanowsky or Wright-Giemsa stain. You may need special stains for some stuff, but this is the general rule. Okay. So, as you know, the white blood cells constitute less than 1% of the total blood cell population. Oh, so why do we care? Because they are part of your immune system, dummy. That's why. The normal white blood cell count is between 4,000 and 11,000 white blood cells per microliter of blood. Now, on the other hand, our bases are fortified millions, not thousands. That's how numerous red blood cells are. Less than 4,000, and you have a condition called leukopenia. Peni means few or a deficiency. More than 11,000, you have a leukocytosis.
Classification of the red blood cell, as you know, depending on the lineage, you have myeloid or lymphoid. According to the structures, you have granulocytes or agranulocytes. Granulocytes include neutrophils with their neutral granules, eosinophils with their eosinophilic granules, basophils with their basophilic granules. Agranulocytes, anything else, such as monocytes and lymphocytes. Now, there is a condition called agranulocytosis. Okay. Now, students get confused. What do you mean by agranulocytosis? Do you mean that the agranulocytes are increased, or that the granulocytes are non-existent? Like, is the 'a' here negative, which means agranulocytes, or is it 'a' negative means there are no granulocytes? Okay. Indeed, agranulocytosis means less granulocytes in your blood. Don't be confused. Granulocytes. Okay. Neutrophils, basophils, eosinophils are absent or decreased in your blood. Basically, agranulocytosis is just neutropenia. That's it.
Okay, we're done. A quick introduction about the white blood cells. In the next video, we will discuss. This was a quick discussion on white blood cells, and the next video we'll discuss lymphocytes. Until next time, be safe, stay happy, and study hard.