Transcription
What is going on, wonderful people? It's Medicosis Perfectionalis, where medicine makes perfect sense. Welcome back to my hematology playlist, which is the most famous playlist on my channel.
This playlist has a lot of videos, but I wanted to give you a general idea of what happens in hematology. Hema means blood, ology means the study of. So, hematology literally means the study of the blood. And as you know, your blood cells come from the bone marrow. By blood cells, I mean red blood cells, white blood cells, and platelets. Click the like button, click the subscribe button, and let's get started. You'll find every topic you need in my hematology playlist.
Here's what we're going to discuss in today's video: introduction to hematology. What is the blood? Well, blood is made of plasma and a bunch of blood cells. We'll talk about the plasma, the plasma proteins, the antibodies, which are gamma globulins, meaning a subtype of plasma proteins. And after we finish talking about the plasma, we'll talk about the blood cells. The blood cells include red blood cells or erythrocytes, white blood cells or leukocytes, platelets or thrombocytes.
All of that was normal, i.e., physiology. But how about the abnormal, pathology? If your red blood cells are low, it's a condition known as anemia. If they're too high, it's polycythemia or erythrocytosis. The cancer of which is called polycythemia vera. If your white blood cells are too low, it's leukopenia. If they're too high, it's leukocytosis. The cancer of which is leukemia or lymphoma. And there are differences between leukemias and lymphomas. If the platelets are low, it's thrombocytopenia. If the platelets are high, it's thrombocytosis. The cancer of which is called essential thrombocytosis, which is essentially a cancer. Cancer of whom? Cancer of the bone marrow because the bone marrow is the source of your blood cells. And of course, if the bone marrow has cancer, the bone marrow will dish all of these abnormal blood cells into the peripheral bloodstream. So, you'll see the cancer cells in the peripheral smear as well. But if you want to find the source, you go to the bone marrow. And that's why in hematology, there are two famous tests to do. Number one is CBC with peripheral smear to look at the periphery. Number two is a bone marrow biopsy to look at the center, i.e., at the bone marrow, the source of all of your blessings or all of your curses, hematologically speaking.
Fun fact, if you take your blood and put it in a test tube and just wait, let it sit or let it stand, what's going to happen? Well, eventually the red blood cells will sink to the bottom and the plasma will float on top. This is called sedimentation of red blood cells, which is a completely normal phenomenon. Could it be abnormal? Yes, depending on your sedimentation rate, meaning erythrocyte sedimentation rate, because your rate could be faster than normal, slower than normal, or just normal. Hence the test, ESR, which I've talked about in a separate video.
Now, let's start. What is the blood? Your blood is made of plasma and blood cells. The plasma is made of water with electrolytes and plasma proteins. The plasma proteins could be albumin or globulins. Globulins are not one, but many. You have alpha globulins, you have beta globulins, and you have gamma globulins. Next, the blood cells. Your blood cells are red blood cells, white blood cells, and platelets. If you just take a look at the plasma versus blood cells, which one is more abundant? The answer is the plasma. It's 55%, so I can draw on that test tube that the plasma from here to here is about 55%, whereas the red blood cells from here to here are only 45% usually. Add them together, you get 100% of course. 45 / 100 is 45%, which is the percentage of red blood cell relative to your blood as a whole, w.h.o.l.e. And this is called the hematocrit value. Hematocrit value is the percentage of your red blood cells compared to all of your blood. So, the numerator has the blood cells, the denominator has all of the blood. You put the red blood cells in the numerator just like this, and you put all of the blood in the denominator just like that. You divide, you give me the percentage. That's 45%, and that is the hematocrit value.
Back to the blood cells, which are not the most numerous. They are divided into red blood cells, white blood cells, and platelets. Among these three, which one is the most abundant? The answer is red blood cells, of course. You have millions and millions and millions of red blood cells per microliter. And of course, you have a lot of microliters in your blood. For dummies, 1 liter has a million microliters. You have about 5 liters of blood. Each liter of blood contains 1 million microliters of blood. Each one microliter of blood contains 5 million red blood cells. That's how abundant the red blood cells are. They are the most numerous cells in your blood. Some argue that they are the most numerous cells in the entire body, but that's something that is very tough to measure. Everything is estimated.
Next, white blood cells. Normal white blood cell count is between 4,000 and 11,000 white blood cells per microliter. Of course, that's nothing when compared to the millions and millions and millions of red blood cells. How about platelets? 150,000 to 400,000 platelets per microliter. Now, it's very clear that your white blood cells are very tiny and the platelets are very tiny when compared to the humongously abundant red blood cells. And that's why in this doozy test tube that I drew here, all of this is your blood cell. The red portion is the red blood cells. This white area, this thin white strip known as the buffy coat, contains both the white blood cells and the platelets. That's how abundant the red blood cells are. That's how tiny the white blood cells and the platelets are in proportion to the red blood cells.
For the physics connoisseurs out there, there is no difference whatsoever between saying microliters and cubic millimeters because 1 microliter is the same as 1 cubic millimeter. They're exactly the same. So, I can say that I have 5 million red blood cells per microliter, or I can say I have 5 million red blood cells per cubic millimeter. Some labs will report the results per microliters, others will report the results per cubic millimeter. The doofus doctor is the one who does not know that these two values are equivalent. Shame. If you want to know how to convert units, please refer to my physics playlist.
And that's it for the blood. Our next topic is the plasma. Please pause and review. Your plasma contains water, electrolytes, and plasma proteins. Water is about 90% of the plasma. The electrolytes include cations like sodium, potassium, calcium, magnesium, and like anions such as chloride, bicarbonate, phosphate, sulfate, etc. What is the most abundant cation in the plasma? The answer is sodium, of course. What is the most abundant anion in the plasma? That's chloride. Please say chloride, not chlorine. Chlorine is a poison. You do not have chlorine in your body. That's toxic, but you do have chloride. And that's why medical textbooks are the only type of books that can kill you from a typo. So, pay attention while writing and while reading. Please do not be another doofus with a stethoscope. We have enough of these already.
The plasma proteins include albumin and globulins. Globulins are many such as alpha globulins, beta globulins, and gamma globulins. Then we have some plasma lipids, cholesterol, triglycerides, phospholipids, a bunch of lipoproteins, and miscellaneous. Blood sugar, amino acids, vitamins, etc. Gases can be soluble in the plasma, or they can be bound to hemoglobin. Gases that are soluble in the plasma include oxygen and carbon dioxide.
If you wish to see more videos like this in the future, drop a heart emoji in the comments. If you wish to download these colorful notes, go to medicosisperfectionalis.com. I help you learn, understand, and pass exams. If you want me to personally tutor you, reach out to me on my website. Oh, by the way, today's just an introduction. If you want the ultimate review, go to my "In 90 Minutes Quick Review" playlist, where you'll find review videos for hematology, cardiology, neurology, pulmonology, endocrinology, and all kinds of topics you can imagine. Review videos for all of the regions in anatomy. Review videos for physiology, biochemistry, molecular biology, genetics, pharmacology, pathology, obstetrics and gynecology, psychology, psychiatry, physics, chemistry, statistics, and much more. The name of the playlist is "In 90 Minutes Quick Review." It has the best videos I've ever made yet.
That's it for the blood and the plasma. Now, let's talk about the plasma proteins. Plasma proteins are albumin and globulins. Globulins are many, including alpha globulins, beta globulins, and gamma globulins. The gamma are the antibodies. Alpha and beta-globulins include coagulation factors such as fibrinogen, which is factor one, prothrombin, which is coagulation factor number two. Albumin is about four, not milligrams, but grams per deciliter. Let me tell you something. What does deci mean? Deci means 1/10 of anything. So, deciliter is 1/10 of a liter, meaning 1 liter contains 10 deciliters. To make sure that you understood this, what is a decimeter? A decimeter is 1/10 of a meter, meaning 1 meter contains 10 decimeters. What is a decamillionaire? It's someone whose net worth is 1/10 of a million, i.e., 100,000. I consider myself not a millionaire, not even but something like a centimillionaire. A centi of anything is 1/100 of that thing. So, a centimeter is 1/100 of a meter. A centimillionaire is 1/100 of a million, i.e., 10,000. 10,000 Zimbabwean dollars. That's my net worth. Why Zimbabwean? Well, just a reference to inflation. That's a topic in economics that I'll tell you about in my economics playlist. Boy, do I have some stories for you.
The globulins are many, including alpha-globulins, which are divided into alpha-1 and alpha-2 globulins, beta-globulins, and gamma-globulins. Alpha-1 globulins include the famous alpha-1 antitrypsin. Alpha-2 globulins include angiotensinogen. These are just examples. The alpha-1 globulins are many, the alpha-2 are many, etc. Beta-globulins include coagulation factor, but to be very honest with you, many coagulation factors are actually alpha-globulins. And then the gamma-globulins are the antibodies, otherwise known as immunoglobulins.
This story is beautiful when you see it on the graph. This is called plasma protein electrophoresis. It tells you that albumin is the most abundant plasma protein in your blood. The others are very tiny when compared to Mr. Albumin. You have alpha-1 globulins, alpha-2 globulins, beta-globulins, and gamma-globulins. Normally, the gamma-globulins are way less than the albumin. But, there is a disease known as multiple myeloma in which the gamma-globulins become abnormally high like this. They spike. Since this is multiple myeloma, we call this the M spike. Or maybe they call the M spike because when you look at this and this together, they make the letter of an M.
How about those immunoglobulins? Well, let's talk about them. But before you do, I need to tell you that you have a bone marrow. The bone marrow has pluripotent stem cells. It will give you all of the blood cells that you can imagine, including B lymphocytes, because these B lymphocytes are the ones that will later develop into plasma cells, and the plasma cells will make antibodies. I am ready to learn about these antibodies, also known as immunoglobulins, otherwise known as gamma-globulins. There is a body and there is an antibody, just like matter and antimatter in physics. Just kidding, it's not like physics. Modern physics has become another metaphysics. It's crazy out there.
Again, your lymphocytes include B lymphocytes and T lymphocytes. The B lymphocytes will become plasma cells, and the plasma cells will make the antibodies for you. How many antibodies do you have? We have five subtypes: IgM, IgA, IgG, IgE, and IgD. Together, they form the Arabic name Majed. Each antibody has heavy chains, the dark blue color, and light chain, the light blue color in this case. Just like the door, the heavy chain has a hinge with a disulfide bond in between. Disulfide, two sulfurs. This is the variable portion. This is the constant portion. V stands for variable, and C stands for constant. The antigen is going to bind here. That's why we say antigen-antibody reaction. Variable is here, constant is here. This is the antigen-binding site. This part binds with the antigen. The antigen is a piece of the invading bacteria or virus, etc. This is the foreign invader. A piece of it is the antigen. It binds to the antibody, hence the antigen-antibody reaction. As for the cell, which could be your macrophage, that is going to bind here. So, the macrophage will bind here, the antigen will bind here, and the complement will bind here. Why do we call it the complement system? Because it complements the function of the antibody. I've talked about the complement pathways in great detail in a video titled "Complement," which you can find in my immunology playlist.
Here's the macrophage binding to this part of the antibody. This is the antigen-binding site. The antigen is a piece of the foreign invader that you're trying to destroy. The antigen will bind with the antibody, forming the antigen-antibody complex. We call this agglutination. The complement will come to help and do complement the function of the antibody. IgG, IgM, IgA, IgD, and IgE. Each one has a separate function, and I've talked about them in great detail in my video titled "Antibodies." See my physiology playlist.
Next, let's talk about blood cells. The blood cells come from the pluripotent stem cells of the bone marrow. These divide into myeloid lineage and lymphoid lineage. The myeloid stem cells are going to give you your red blood cells and your platelets and many of your white blood cells, basically all of your white blood cells except the lymphocytes and the natural killer cells. Those come from the lymphoblasts. Speaking of myeloid stem cells, they give us proerythroblasts, erythroblasts, normoblasts, reticulocytes, then erythrocytes. Up here, we're very premature or immature. Down here, we're very mature. As you go down and down and down from the immature to the mature, the size of the cell decreases and decreases and decreases some more.
Next, the myeloblasts will give us the myelocytes. These will give us granulocytes. What are the granulocytes? Granulocytes are BEN: B, E, N – basophils, eosinophils, neutrophils. Why do you call them basophils? Because they have basophilic granules. Why do you call these eosinophils? Because they have eosinophilic granules. By the way, basophilic means blue, eosinophilic means pink if we use a certain stain. But what does neutrophils mean? It means that they have neutral granules that are neither blue nor pink, neither acidophilic nor basophilic. The monoblasts will give us the monocytes. The megakaryoblasts will give us megakaryocytes, and the megakaryocyte will literally explode into a thousand pieces. Each piece is called a platelet. All of that was the myeloid lineage.
How about the lymphoid lineage or the lymphoid stem cells? They give us lymphoblasts, and the lymphoblast will give us lymphocytes and natural killer cells. Don't forget that the B lymphocyte will become a plasma cell, and the plasma cell will make antibodies. We can divide white blood cells into granulocytes and non-granulocytes. The granulocytes are BEN: B, E, N – basophils, neutrophils, eosinophils. Basophilic granules, eosinophilic granules, neutral granules. Basic, acidic, neutral. The non-granulocytes include the monocytes and the lymphocytes.
There is a certain factor or a protein or a peptide that can stimulate the growth and development and proliferation of granulocytes. This is known as G-CSF, granulocyte colony-stimulating factor. But what if I want to boost these other guys? You have M-CSF, the monocyte colony-stimulating factor, to stimulate the monocyte. What if I want to stimulate both sides? Then you have GM. Here's the G, here's the M-CSF.
There is a condition in pathology known as agranulocytosis. Break that down for me. What does -osis mean? Condition. What does granulocyte mean? A cell with granules like these three: basophils, eosinophils, neutrophils. What does A mean? A means no. So, this is a condition of absence of granulocytes. The patient does not have enough basophils, neutrophils, eosinophils. That is agranulocytosis. You can also call it granulocytopenia. Granulocytes, -penia. -Penia means less or fewer or lower than normal.
Speaking of white blood cells, we have neutrophils, lymphocytes, monocytes, eosinophils, and basophils. I have rearranged them from the most abundant in your blood to the least abundant in your peripheral blood. Neutrophils are about 60% of the white blood cells. Lymphocytes, about 30% of the total leukocytic count. Remember that leukocyte means white cells. So, white blood cells are the leukocytes. The total leukocytic count is the total number of all of the white blood cells. Monocytes, 3 to 7% of the total leukocytic count. Eosinophils, 1 to 3% of the total white blood cell count. Basophils, 0 to 1% of the total white blood cell count.
If I told you that the total leukocyte count is between 4,000 and 11,000 white blood cells per microliter, let's take an average, say 5,000. If you multiply the 5,000 by the relative count of neutrophils, you're going to get the absolute count of neutrophils. Multiply 60% by 5,000 is about 3,000. So, the 3,000 will be the absolute neutrophilic count, whereas the 60% is the relative neutrophilic count, meaning relative to the total leukocyte count.
Your neutrophils fight bacteria. These are the cells that make pus. These are the cells of the acute inflammation. The lymphocytes attack viruses, fungi. These are the cells of chronic inflammation. These are the cells of the granuloma. Monocytes become macrophages in the tissue. They too can help you make a granuloma. Eosinophils attack parasites. Eosinophils with the E, think "Ew." Everything is ew, it's gross, it's allergy, ew, anaphylaxis, ew, hypersensitivity, double, triple ew. Basophils are ones that make histamine. Basophils are kind of similar to mast cells. They are not identical, but they are kind of similar.
Monocytes in the blood are the equivalent to macrophages in the tissue. They're equivalent to the Kupffer cells in the liver, to the microglia of the nervous system, to the osteoclasts in the bone. These love to eat stuff and break down stuff. So, the osteoclasts will break down bones. The microglia will destroy the invaders that try to invade your nervous system. The cells of acute inflammation are mainly the neutrophils. These are polymorphonuclear cells, or PMNs for short. Whereas, the lymphocytes are the main cells of chronic inflammation. These are mononuclear cells because their nucleus has one shape, whereas the PMNs have different segments and different shapes.
Here are the sequelae of acute inflammation. Here are the consequences of chronic inflammation. Don't you know that chronic inflammation can lead to malignant transformation? So, chronic inflammation of the liver, chronic hepatitis, can later become cancer of the liver, hepatocellular carcinoma. And chronic inflammation of your stomach, chronic gastritis by H. pylori, can later become a gastric cancer. To learn more about acute versus chronic inflammation, see my video titled "Acute Versus Chronic Inflammation" in my pathology playlist.
A quick note on the immune system. Your B lymphocytes are responsible for humoral immunity. What does humoral mean? Here is a lesson in history. Do you remember the ancient Greek theory of the four humors? Blood, phlegm, yellow bile, black bile. Do you remember that? These were known as the four humors, humors, fluids. Why? Because the B lymphocytes become plasma cells, and the plasma cells secrete antibodies into the bodily fluids, such as the plasma, such as your tears, such as breast milk, such as all of the mucosal secretions, etc., etc., etc. As for the T lymphocytes, they do not secrete antibodies, but rather they punch the invader in the face, cell to cell, or cell-mediated immunity, or cellular immunity. You punch the fungus in the face, punch the cancer cell in the face, punch the virus-infected cell in the face. As for the B lymphocytes, they help us fight bacteria, whereas the T lymphocytes will help us fight virus-infected cells, fungi, and cancer cells. Meaning, if you have a strong immune system, you will have a lower risk of cancer. Conversely, if you have a poor immune system, you will have a greater risk of cancer. Thus, take care of your immune system, your immune system takes care of you.
Here are the B lymphocytes, and here are the T lymphocytes. The question is, who made them? What is the site of production? The answer is, it's the bone marrow for the B cell and for the T cell. But, where do they mature and grow up and get their training? Now, there will be a difference. The B cells grow up in the bone marrow, whereas the T cells grow up in the thymus, the thymus gland. Or as my professor used to say, the thymus. After they get their training in school, they need to go out to the real world and practice their craft. Well, you will find the B lymphocytes working in the lymph nodes and also in the spleen. How about the T lymphocytes? Same thing, they will work in the lymph node and in the spleen. The B cells exist to help you fight bacteria and to make plasma cells to make antibodies. The T cells exist to help you fight virus-infected cells, fungi, and cancer cells. Lucky for your lymphocytes, they do not have to deal with Karens in HR. But, they have to deal with tuberculosis, syphilis, salmonella, shigella, measles, mumps, and rubella.
Do these white blood cells talk to each other? Yes. Unlike your doctors, your white blood cells are very good at communicating by means of interleukins. Break that down for me. Why does it end in -in? Because it's a protein, or at least a peptide. Why leuk? Because it's a reference to leukocytes, or the white blood cells. And inter means between. So, think of the interleukin as the internet of your leukocytes that helps them communicate. And these are proteins or peptides. Interleukins belong to a bigger group of molecules known as the cytokines. What does that mean? Cyto means cells. Kines from kinetic, to move. Oh, meaning to influence the cells to produce a certain function. Cytokines are many. They include interleukins, colony-stimulating factors, we just saw G-CSF versus GM-CSF, as well as tumor necrosis factors, or TNF. I've talked about these doozies in my pathology playlist. I have a very comprehensive video on the interleukins, which was epic.
Is the baby genetically identical to the mother? The answer is absolutely not. Then how come the mother's immune system does not recognize and destroy the fetus? Well, the answer is, during pregnancy, the mother puts herself in a state of immunosuppression, i.e., she makes fewer antibodies, etc., etc., etc. And that's why the mother does not attack the fetus. And since the mother is in a state of immunodeficiency during pregnancy, we will not give the mother live attenuated vaccines during pregnancy, because the mother's immune system during pregnancy is weak, and she can't handle the truth. I mean, she can't handle the live attenuated vaccines. Not only is the fetus genetically different from the mother, the fetus is also immunologically different from the mother. A fact that has immense clinical significance when you learn about the disease known as Rh incompatibility, discussed in my hematology playlist.
Your immune system is strong. The question is, why does it kill foreign invaders but not you? Well, the answer is, because my immune system can recognize me. It can recognize my cells and avoid destroying them. And it can recognize the foreign invaders and beat the living hell out of them. The ability of my immune system to recognize my cells is called recognition of the self. It's thanks to the great help of the T regulatory cells, formerly known as the T suppressor cells, because they suppress your immune system when you recognize you. When you recognize your cell, you should not kill. And this is called self-tolerance, or tolerance to your own cells. This is absolutely normal. What if this mechanism of self-recognition and self-tolerance is busted? Well, you will have the opposite. You will attack yourself, and that's a disease. It's a bunch of diseases known as autoimmune diseases. Auto means self, immune. Oh, my immune system is attacking myself, and that's a disease. Autoimmune diseases are many. Here are just a few examples: Type 1 diabetes, where you have nasty antibodies attacking your pancreas. Myasthenia gravis, where you have nasty antibodies attacking your nicotinic sub M acetylcholine receptor at the neuromuscular junction, or the motor end plate. Celiac disease, where you have awful antibodies attacking tissue transglutaminase in the small intestines. Don't forget rheumatoid arthritis, systemic lupus erythematosus, and many other diseases. I've talked about the autoimmune diseases in my rheumatology playlist. You can learn more about the MHC, lymph, lymph vessels, lymph nodes, and more in my hematology playlist. To learn about the immune system, check out my immunology playlist.
We're done with the normal physiology. Let me introduce you to the diseases. If you have too few red blood cells, that's anemia. Too many, that's polycythemia, or erythrocytosis. Poly means many. Cythemia means red cells in the blood. To be honest, cyte just means cells, not necessarily red blood cells, but here it means red blood cell, especially when you later learn about the condition polycythemia rubra vera. Rubra is red, and cyte is cell. So, rubra and cyte, that's a red blood cell. Erythro means red. Cyte is cell. -osis is a condition. It's a condition of having too many erythrocytes or too many red blood cells in your blood. How about white blood cells? Too few, leukopenia. Leuko- means leukocytes or white blood cells. -penia means few or little or less than normal. What if I have too many? That is leukocytosis. How about platelets? Too little, thrombocytopenia. Thrombocytes, the cells of thrombosis, i.e., the platelets. -penia means little or few. What about having too many platelets? This is called thrombocytosis or thrombocythemia.
Now, if the red blood cells are too many, this could be not cancer or it could be cancer. If it's cancer, it's called polycythemia vera. If you have too many white blood cells, it could be not cancer, such as the leukemoid reaction, but it could also be cancer, such as leukemia and lymphoma. Leukemia is to the bone marrow what lymphoma is to the lymph node. The site of production of your lymphocytes versus the site of maturation of your lymphocytes. If the platelets are too high, this could be not cancer or it could be cancer. If it's cancer, we call it essential thrombocytosis. The cancers are written in square brackets.
You see this? These are your red blood cells or erythrocytes. If you have too few, that's anemia. Too many, that's polycythemia or erythrocytosis. If it's cancer, it's polycythemia vera or polycythemia rubra vera. Rubra means red. Erythro- means red. Educated people do not use the word red to describe this color. Instead, they use rubra or erythro. Don't say that in a supermarket because you might get arrested. No one is going to understand you. After watching many of my videos, my students are as high as a kite.
How about platelets? These are the platelets. If you have too few, thrombocytopenia. Too many, thrombocytosis or thrombocythemia. How about my white blood cells? Too little, leukopenia. Too many, leukocytosis.
So, let me give you a very quick synopsis on anemia, a quick summary on polycythemia. Anemia, what's going on? Well, in anemia by definition, you have less red blood cells than normal. This means decreased red blood cell mass. But, it's very difficult to measure red blood cell mass. This implies that I measure all all of the red blood cells in all of your body. Do you want me to empty your body from every single drop of blood? Hell, no. So, what do I do if I cannot accurately measure them? Well, you can estimate them by measuring the red blood cell count in a sample of blood, just a sample. You can measure hemoglobin concentration in a sample of blood, just a sample. And you can measure the hematocrit value in a sample of blood. In all of these tests, red blood cells are low, hemoglobin is low, hematocrit is low if you suffer from anemia.
What does anemia mean? An- means no, -emia means blood. So, anemia literally means no blood. In reality, it means less red blood cells. One of the functions of red blood cells is to carry oxygen throughout your body and give that oxygen to the tissue. But, what if you have less red blood cells? Then you will carry less oxygen and therefore you will be tired and pale, pale and tired. So, what's the definition of anemia? Etymologically, an-emia, it means no blood. Pathologically, anemia is defined as decreased total red blood cell mass, which is a type of decreased oxygen carrying capacity of the blood. What is the laboratory diagnosis of anemia? Decreased red blood cell count, decreased hemoglobin, and decreased hematocrit. What is the clinical definition of anemia? Tired and pale, pale and tired. Sometimes I have angina. Sometimes I get a murmur. I'm dizzy. I'm exercise intolerant. I'm short of breath, etc., etc., etc. The difference between oxygen content, oxygen saturation, partial pressure of arterial oxygen, hemoglobin concentration were discussed in great detail in my pulmonology playlist.
Here are the signs and symptoms of anemias. All of the anemias, whatever the cause, whatever the type, can give you tired and pale, pale and tired, short of breath, dizzy. Sometimes you get a murmur. It's an innocent systolic flow murmur. The murmur of anemia is always systolic and never diastolic. The valves are not sick. It's just an innocent murmur. Maybe you get a headache. Maybe exercise intolerance and a hyperdynamic circulation. Because if you have fewer red blood cells than normal, you will be able to carry less oxygen. So, at least you can make them circulate faster in response to the low red blood cells.
We divide anemias into microcytic, normocytic, and macrocytic. What does microcytic mean? It means that each cell is small. Normocytic, the cells are normal in size. Macrocytic, these red blood cells are huge, macro. How can you measure the volume of the cell? Well, I do not measure the volume of a singular cell, but of a group of cells. And this is the mean corpuscular volume. Mean here means average, not as in why are people so mean. Corpuscular, oh, the corpuscle in medicine refers to the red blood cell. But, if you're talking about renal corpuscle, it refers to the glomerulus of the kidney. When Sir Isaac Newton was talking about a corpuscle of light, it was a reference to the particle of light, what we now call the photon. Isaac Newton did not see light as waves. Shame on you, sir. See my physics playlist to learn more. If the mean corpuscular volume is normal, it's normocytic. If it's low, it's microcytic. If it's high, it's macrocytic. Because it's the volume of your red blood cells.
What causes anemia? There are many causes of anemia. Except for acute blood loss or splenic sequestration of blood, most common causes of anemia are either hypoproliferative in nature or a defect in survival. Causes of anemia could be less production than normal or maturation defect or survival defect or sequestration in the spleen or loss of blood. Maybe in a car accident or maybe you're bleeding from your gut. In this series of hematology, you will hear this a lot that anemia is either caused by underproduction or overdestruction, particularly the normocytic anemia.
What causes microcytic anemia? Well, your red blood cells have hemoglobin. Hemoglobin is made of heme and globin. Heme is made of iron and protoporphyrin. Therefore, microcytic anemia could be caused by iron deficiency or anemia of chronic disease. In iron deficiency, you do not have enough iron. In anemia of chronic disease, you do have iron, but you cannot use it. Or maybe you have sideroblastic anemia, a problem in the protoporphyrin. Or maybe you have thalassemia, a problem in the globin. There are two types of globin. There is alpha globin and beta globin. If the defect is in the alpha globin, we call it alpha thalassemia. If the defect is in the beta globin, we call it beta thalassemia. What does thalassemia mean? -emia means blood. Thalassus is the Mediterranean Sea, and that's why thalassemia, particularly beta thalassemia, is common around the Mediterranean. This is where I came from.
Can sickle cell disease cause anemia? Yes, it's a hemolytic anemia, usually normocytic. Can you answer these questions about sickle cell anemia? If you know, comment below. You'll find the answer key in this hematology playlist.
Next, quick notes on polycythemia. If I just say polycythemia or erythrocytosis, it could be cancer or not. But, when I say polycythemia vera, this is cancer, cancer of the bone marrow. Polycythemia vera is a cancer of the bone marrow that makes too many red blood cells. It also makes too many platelets and white blood cells. That's why it's a myeloproliferative disorder. Normally, there is something that comes out of your kidneys known as EPO or erythropoietin. Normally, erythropoietin goes to your bone marrow and tells your bone marrow to make more red blood cells. But, if you have cancer in the bone marrow that already makes too many red blood cells, then this will decrease the secretion of EPO from the kidney as a negative feedback loop.
Next, what's the difference between leukemia versus lymphoma? Leukemia is a cancer in the bone marrow. Lymphoma is a cancer in the lymph nodes. When the cancer is in the bone marrow, as in the case of leukemia, all of these malignant cells that start in the bone marrow will eventually go to the blood because the bone marrow is the source of all of the blood cells. In lymphoma, you'll find the cancer cells in the lymph node. So, if you want to diagnose leukemia, what do you do? You biopsy the bone marrow. If you want to diagnose lymphoma, what do you do? You biopsy the lymph node. There is a famous video in my hematology playlist called "Leukemia Versus Lymphoma Distinctions in Oncology," in which I've told you that leukemia is like a lemonade, whereas lymphoma is like a lemon. One is liquid, the other is solid, a solid lymph node. Don't forget to watch this video.
A quick note on thrombocytopenia. Thrombocytopenia, less thrombocytes, which means less platelets. The textbook definition of thrombocytopenia is platelet count less than 150,000 platelets per microliter. In reality, or clinically speaking, doctors don't care that much about your platelets until they drop below 50,000. That's when the patient starts to have symptoms. The lower the platelets count, the worse the symptoms. Less than 5,000, that is really bad. Many surgeons will refuse to operate on you until you bring your platelet count to 50,000 or higher, 50,000 per microliter. Why are these surgeons so cowardly? Well, because if your platelet count is too low, you're going to bleed, and you will not be able to handle the truth. I mean, the surgery.
Let's talk about thrombocytosis. Thrombocytosis means too many platelets, exceeding 400,000 platelets per microliter. Thrombocytosis could be cancer, or maybe not. But, when I say essential thrombocytosis, that's a cancer. A cancer of the bone marrow that makes too many platelets. It also makes too many red blood cells and white blood cells, meaning it's another myeloproliferative disorder, just like polycythemia vera. You can learn about all of these doozies in my hematology playlist.
Hopefully, you learned something today. In this video, we talked about your blood, which is made of plasma and blood cells. The plasma is made of water, electrolytes, and plasma proteins. The plasma proteins are albumin and globulins. The globulins are many, including alpha globulin, beta globulin, and gamma globulins. Gamma globulins are the antibodies, or the immunoglobulins, made by the plasma cells. Plasma cells came from the B lymphocytes. B lymphocytes are white blood cells. Your blood cells are red blood cells, white blood cells, and platelets. Disorders of the red blood cells could be anemia or polycythemia. Disorders of the white blood cells could be leukopenia or leukocytosis. Diseases of the platelets could be thrombocytopenia or thrombocytosis.
On my website, I have a notebook that summarizes all of the lymphomas for you. I call it "Perfectionalis Ultimate Notebook," or PUN lymphoma. You can download it at medicosisperfectionalis.com. You download it once, and you keep it for you forever. And, I have another notebook on leukemia, medicosisperfectionalis.com. And, I have 50 cases on bleeding and coagulation disorders, also on my website. If you value what I do, help me make more videos by supporting the channel. Go to buymeacoffee.com/medicosis. There are more than 750 premium videos available on this channel when you click the join button and choose the highest tier. Please subscribe, hit the bell, smash like, support my channel on Patreon, PayPal, or Venmo. Go to my website to download my courses, notes, and cases, or if you would like me to personally tutor you. Be safe, stay happy, study hard. This is Medicosis Perfectionalis, where medicine, chemistry, math, and physics make perfect sense.