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Current time:0:00Total duration:10:19

Video transcript

so as their name suggests red blood cells are actually red and they're found in the blood so this little blood vessel and that's a blood inside so red blood cells are found in the blood but this is actually the end of the story right because red blood cells even though they're found in the blood they're actually not made there they're actually made inside bone right so this is a picture of a bone not a really good one but that's a picture of a bone and inside the bone you have this this cavity in the center of the bone so much so that if you took a slice of the bone like that and you were to look into it look kind of like head on to it you'd see that on the outside of bone there's this hard part this hard white part that we all know about but in the center there's this red spongy tissue and that stuff that red spongy tissue is called bone marrow bone marrow marrow and bone marrow is where all of the different blood cells are made including red blood cells that's where they're made now even this isn't the start of the story because the bone marrow is instructed by the kidney to make the red blood cell so here's the kidney and the kidney releases this molecule this hormone called erisa row called urethral with row PO Eaton PO Eaton that's often abbreviated e P o write and erase or point until erisa row a wrist roll with row means red and erythropoiesis very similar word or it's or poesis means to make red blood cells so erythropoietin is a hormone that's released from the kidney that tells the bone marrow to make red blood cells okay but how does it do that well inside the bone marrow there's this cell the main cell if you will of the bone marrow is called the cell right here it's called a hematopoietic mado poetic wedeck stem cell right stem cell and this stem cell gives rise to all of the different blood cells whether it's a red blood cell a white blood cell or platelet they all originate from a hematopoietic stem cell so erisa ropo eaten released from the kidney once again instructs the hematopoietic stem cell to form a red blood cell so the hematopoietic stem cell then develops into an immature red blood cell that's what I'm drawing it over here so it's a pretty big cell right and inside the cell there's a nucleus that's a nucleus right there and nucleus contains DNA so that's a cell's DNA and this immature red blood cell this precursor red blood cell is called in erythro blast a RIF ro blast okay and the erythro blast is it's an immature cell eventually it matures into a mature red blood cell and a mature red blood cell is called an erythro it's called an erythrocyte right erythro again means red site means cell so there's a red blood cell and as you can tell the erythrocyte looks pretty different from an oral blast for one thing there's no nucleus inside the erythrocytes and hence it has no DNA no DNA also you can see that there is no site has no organelles so it has no mitochondria no ribosomes it's given all of that stuff up so what does the erythrocyte have inside well there is ro site has inside of it lots and lots of hemoglobin hemoglobin and what is hemoglobin well hemoglobin is a protein that binds to oxygen so we know that red blood cells serve the function of of carrying and delivering oxygen and it's hemoglobin that allows the red blood cells to serve that function because it's the hemoglobin that actually binds to the oxygen and you can see that red blood cells are pretty committed to their job of carrying oxygen because they empty their selves pretty much anything else fill themselves up of hemoglobin so that all they do is carry oxygen so all in all this is what the lifecycle of a red blood cell looks like and this blood cell will live for 120 days before it's taken out of commission so we were talking before about anemia anemia and how anemia refers to a decrease of shortage in a number of red blood cells so there are too few red blood cells in the body and there are many different causes of anemia so much so that we could probably spend the entire week talking about the different causes of anemia but the people who first described the anemias ask themselves a very important question they ask themselves is the decrease in the number of red blood cells because there's a problem in making the red blood cells or is it a problem of normal healthy red blood cells being destroyed so in essence they drew a line down the middle of this diagram that was fun so I'm going to do that again right so they drew a big line down the middle of this diagram where above this line you're looking at anemias that are caused by a problem with under production under production and below this line right you're looking at a problem where healthy normal red blood cells are being destroyed so you're looking at a problem of destruction destruction and we're going to go through the different types of under-production anemias and the different types of destruction anemias in great detail but for right now I just like to graze over the different types ok briefly and I'd like to use really bright colors so that's good so minty green so let's start off with the kidney so if let's say a person was suffering from renal failure from kidney failure and they weren't able to produce as much a restore point that would cause an under stimulation of this entire process right that would certainly lead to an under production anemia what about moving on what if what if the bone marrow was sick because it was infected by virus so what it feels too sick to produce red blood cells or what if it was taken over by tumor or or or fibrosis scar tissue and it didn't have enough room to produce red blood cells that would lead to an under production anemia and what if this original blast looking at this risk were blessed you see it has this huge nucleus and it has lots of DNA in the center what if we didn't have enough precursors to make all of this DNA well that would prevent us from making as many erythro blasts and his many erythrocyte so that would be a cause of an under production anemia and finally getting to this erythrocyte we said that it's filled Chuck filled of hemoglobin and hemoglobin has lots of different components to it what if there was a shortage of one of those component right or problem making the hemoglobin that would be one of the most common causes of an under production anemia now those are the different causes of under-production anemia what if we had healthy red blood cells and good quantities being released into the blood but our immune system started to attack the red blood cells start to destroy the red blood cells that would be a cause of a destruction anemia and what if instead of our immune system attacking the red blood cells what if what if pathogens such as viruses and bacteria started to attack the red blood cells that would be another cause of a destruction anemia and finally I'm going to complete the rest of this blood vessel what if we had what if we had a situation like this where you have this blood vessel and there's a hole in it a tear and the blood just starts to escape and hemorrhage out well that loss of red blood cells because of the loss of blood would be another cause of a destruction anemia so that's an overview a very brief overview of the different types of anemias that we're going to talk about in greater detail later but one point that I'd like to leave you with is that this this division is pretty intuitive then there's actually a hint that we can find in lab values that helps us to determine whether we're looking at an under production anemia or a destruction anemia if we have a destruction anemia you can imagine that the bone marrow and the kidney would work extra hard they would ramp up their processes to compensate for that loss they would try to pump out more and more red blood cells you'd start to see in fact immature red blood cells being released into the blood because the bone marrow is working so hard and so fast to release new red blood cells and those young red blood cells kind of a step between the river blasts and the erythrocytes are called are called reticulocyte reticulocyte reticulocytes ut lots of reticulocytes specifically greater than three percent because 3% is the amount that you normally see in blood if you see greater than 3% you can assume that we have a destruction anemia now in an under production anemia your bone marrow or kidney could be the problem so they're not able to compensate by increasing their production of young red blood cells so you'd see a decrease in the reticulocyte count so instead of having 3% which we said was normal right you'd have less than 3% and that's one really quick and easy way to tell the difference between whether you're looking at an under production anemia or a destruction anemia