Transcription
Okay, hematopoiesis. This is a very crucial topic to understand hematology, or blood. So, all of the blood cells that we know and love start from the bone marrow. This is the factory that produces blood cells. So, there are stem cells in the bone marrow, and the type of these stem cells are pluripotent pluripotent stem cells. What are the different types of stem cells? That's an entirely different subject. Okay.
Hopefully, a very crucial topic to understand hematology or blood. So all of our blood cells that we know and love start from the bone marrow. That's the factory from stem cells called multipotent stem cells. So what are the different types of stem cells? That's an entirely different topic, which is beyond the scope of this video. For now, just know they are multipotent, which means they can produce many different cells. Okay.
Then, this multipotent stem cell will produce a myeloid stem cell and lymphoid stem cell. The myeloid will further subdivide into four things: proerythroblast, myeloblast, monoblast, and megakaryoblast. Okay.
What about the lymphoid stem cells? They will give B lymphocytes and T lymphocytes, and that's it. Okay.
The myeloid proerythroblast has the word "erythro," which means red, so it will give the red blood cells, also known as erythrocytes. "Site" means cell; "blast" is a big cell that will form this small cell. So this is the parent; this is the child. So, proerythroblast, normoblast, reticulocyte, erythrocyte. Okay.
What about this one? Myeloblast. Myeloblast will produce promyelocytes, and that will differentiate to three different types: neutrophilic myelocytes, basophilic myelocytes, eosinophilic myelocytes. Each of them will change into neutrophilic metamyelocytes, basophilic metamyelocytes, eosinophilic metamyelocytes, then into the cell: neutrophils, basophils, eosinophils. If you pay attention, you will see some dots here; these are granules. Granules. These spots are the granules. Granules, granules. So, as like those three combined will be called granulocytes. Granulocytes. It will be important when we study a disease called agranulocytosis, which means absence of the granulocytes. Okay, but that's an entirely different subject. Okay.
What about now? Now we have the monoblast. Will change into promonocyte, then into the monocyte. There are no granules here, so those are agranulocytes, okay, or non-granular cells. Megakaryoblast. Megakaryoblast will change into promegakaryocyte, then megakaryocyte, then platelets. Okay.
Take care. Only the white blood cells here, only those white blood cells from here to here. Okay, and those also are white blood cells. Those have a nucleus; the others are anuclear. Okay, that's it.
So what's the function of every single cell of these? So the red blood cell, as you know, they transfer oxygen to the tissue. What about the platelets? They will help in the primary hemostasis, which is the control of bleeding. Okay, the clotting mechanisms. Fine. What about these granulocytes? So, as the granular, as for the granulocytes, the neutrophil will be will fight bacteria and fungus. The basophil will produce histamine. What about the eosinophils? They will fight large parasites, and they will modulate some inflam- some allergic inflammatory responses. What about the lymphocytes? The B cell is responsible for the humoral immunity, and the T cell is responsible for the cell-mediated immunity, or cell-mediated immunity. That's it. Enjoy hematopoiesis. Multipotent stem cells. Wow, that's great.