HAEMOPOIESIS
HAEMOPOIES
by: Nurul Shafiqa
Have you guys ever wonder how does our blood being produced?
Do you know where exactly is the blood formation takes place?
I know some of you might not interested to know about this scientific processes, but as for me,it is fun to know what our body have gone through everyday. Although I used to be like that too when I was a kid, now i feel grateful that I have to learn this to pass my exams. It sounds like I was being forced, hahahaha somehow it's true.😝Nope, we shouldn't be like that! What we learn today must be very useful for our future. Not only we can get benefit from the knowledge, but we also learn on how to appreciate what does our God gives us and be more grateful of what we have compared to other people out there.
I still remember the time I fell from my bicycle. I was 6 that time. That is because I wasn't listening to my mom. I still wanna play with my friends although it was just few minutes after the rain stopped. I rode my bicycle down the hill to chase my friend. I forgot that the road was too slippery. I used all of my strength to push the pedals to increase my speed. But then, I couldn't control the handle as my left hand was holding my skirt. Yes, I was riding bicycle using one hand only. Now I realized, how stupid I was that time.
unfortunately, I fell down. I got bruises all over my body, and I can see blood everywhere. "exaggerated" hahaha. Can I know, what is the first thing you guys do when you got injured? Absolutely, you will call out your mom and running towards her to show the injured area right?
The sad part is, my mom would only say; "serves you right". Yes, I know she will respond like that but I still wanted to tell her first.
That was the beginning of my story. The point where I started to ask myself of how does our body function although there was many blood come out. The question only goes in my mind but never goes out. I know, if I ask my mom, she would answer that was created by God. That's all😑
As I am getting older, I have learnt so many things. That was how I got the answers of all my questions. I started to discover about myself and getting to know me better.
So, what I was trying to tell you guys is actually our blood doesn't stop producing since we were born until now. It keeps producing to replace other damaged blood cells. If there is break down of blood cell (catabolism) , there should also be production of blood cells (anabolism). This process called haemopoiesis and it mainly occurs in our bone marrow. Blood cells are not just about red blood cell(erythrocyte). They also contain 5 types of white blood cells(leukocyte) and platelet(thrombocyte).To those who doesn't know what are those 5 types of white blood cell, basically they are including Basophil, Neutrophil, Eosinophil, Lymphocyte and Monocyte.
Before that, let me briefly explain about haemopoiesis so that you guys could have some rough ideas about it before I explain it in details. Haemopoiesis or else known as hematopoisis is a process of blood cell formation, differentiation and development. Prenatally occurs in yolk sac then in liver and bone marrow. This is because bone marrow is not fully developed in fetus. In adults, it occurs in bone marrow and thymus.
Here is the mind map to simplify how does our blood being formed.
This process starts with pluripotential (immature) stem cells. This cell will divide into myeloid and lymphoid progenitor (parent) cells. Myeloid stem cells will further divide into red blood cell, white blood cell and platelet. Lymphoid stem cells will further divide into lymphocytes (B cell, T cell and natural killer cell) Why does our body use stem cells to do haemopoiesis? This is because stem cells have the ability to divide many times and different types.
To know more about the steps involve in haemopoises, you guys can have your own reading through this website (in the form of article);
http://www.blackwellpublishing.com/content/BPL_Images/Content_store/Sample_Chapter/9781405136495/9781405136495_01.pdf
Normal sites of haemopoiesis
Sites of haemopoiesis vary with human development such as during fetus, infants and adults.
In fetus, haemopoiesis begins at 19th day of life producing red blood cell (pool of blood island & big erythroblast) at yolk sac. After 2 months, cells migrate to liver and spleen, Then, after 4 months medullary haemopoiesis begins in bone marrow.
While after birth or in infants until 3 years old, haemopoiesis or haematopoiesis occurs in red bone marrow of almost every bone. Beginning at 4 years old, skeleton growth exceed the demand of red blood production. Therefore, haemopoietic activity moves to axial skeleton (flat bone, skulls, ribs, sternum, clavicle, vertebrae, pelvic) and proximal end of long bones (humerus and femur) completed at 18 years old.
As we getting older, our marrow cavities are replaced with fat (yellow bone marrow) and at age 40 years old, composition of our fat and haemopoietic tissue are equal.
But, in some cases extramedullary haemopoiesis can occur in adult if
When extramedullary haemopoiesis occur, we might having some problem or certain disease.
by: Nurul Shafiqa
Have you guys ever wonder how does our blood being produced?
Do you know where exactly is the blood formation takes place?
I know some of you might not interested to know about this scientific processes, but as for me,it is fun to know what our body have gone through everyday. Although I used to be like that too when I was a kid, now i feel grateful that I have to learn this to pass my exams. It sounds like I was being forced, hahahaha somehow it's true.😝Nope, we shouldn't be like that! What we learn today must be very useful for our future. Not only we can get benefit from the knowledge, but we also learn on how to appreciate what does our God gives us and be more grateful of what we have compared to other people out there.
I still remember the time I fell from my bicycle. I was 6 that time. That is because I wasn't listening to my mom. I still wanna play with my friends although it was just few minutes after the rain stopped. I rode my bicycle down the hill to chase my friend. I forgot that the road was too slippery. I used all of my strength to push the pedals to increase my speed. But then, I couldn't control the handle as my left hand was holding my skirt. Yes, I was riding bicycle using one hand only. Now I realized, how stupid I was that time.
unfortunately, I fell down. I got bruises all over my body, and I can see blood everywhere. "exaggerated" hahaha. Can I know, what is the first thing you guys do when you got injured? Absolutely, you will call out your mom and running towards her to show the injured area right?
The sad part is, my mom would only say; "serves you right". Yes, I know she will respond like that but I still wanted to tell her first.
That was the beginning of my story. The point where I started to ask myself of how does our body function although there was many blood come out. The question only goes in my mind but never goes out. I know, if I ask my mom, she would answer that was created by God. That's all😑
As I am getting older, I have learnt so many things. That was how I got the answers of all my questions. I started to discover about myself and getting to know me better.
So, what I was trying to tell you guys is actually our blood doesn't stop producing since we were born until now. It keeps producing to replace other damaged blood cells. If there is break down of blood cell (catabolism) , there should also be production of blood cells (anabolism). This process called haemopoiesis and it mainly occurs in our bone marrow. Blood cells are not just about red blood cell(erythrocyte). They also contain 5 types of white blood cells(leukocyte) and platelet(thrombocyte).To those who doesn't know what are those 5 types of white blood cell, basically they are including Basophil, Neutrophil, Eosinophil, Lymphocyte and Monocyte.
Before that, let me briefly explain about haemopoiesis so that you guys could have some rough ideas about it before I explain it in details. Haemopoiesis or else known as hematopoisis is a process of blood cell formation, differentiation and development. Prenatally occurs in yolk sac then in liver and bone marrow. This is because bone marrow is not fully developed in fetus. In adults, it occurs in bone marrow and thymus.
Here is the mind map to simplify how does our blood being formed.
This process starts with pluripotential (immature) stem cells. This cell will divide into myeloid and lymphoid progenitor (parent) cells. Myeloid stem cells will further divide into red blood cell, white blood cell and platelet. Lymphoid stem cells will further divide into lymphocytes (B cell, T cell and natural killer cell) Why does our body use stem cells to do haemopoiesis? This is because stem cells have the ability to divide many times and different types.
To know more about the steps involve in haemopoises, you guys can have your own reading through this website (in the form of article);
http://www.blackwellpublishing.com/content/BPL_Images/Content_store/Sample_Chapter/9781405136495/9781405136495_01.pdf
Normal sites of haemopoiesis
Sites of haemopoiesis vary with human development such as during fetus, infants and adults.
In fetus, haemopoiesis begins at 19th day of life producing red blood cell (pool of blood island & big erythroblast) at yolk sac. After 2 months, cells migrate to liver and spleen, Then, after 4 months medullary haemopoiesis begins in bone marrow.
While after birth or in infants until 3 years old, haemopoiesis or haematopoiesis occurs in red bone marrow of almost every bone. Beginning at 4 years old, skeleton growth exceed the demand of red blood production. Therefore, haemopoietic activity moves to axial skeleton (flat bone, skulls, ribs, sternum, clavicle, vertebrae, pelvic) and proximal end of long bones (humerus and femur) completed at 18 years old.
As we getting older, our marrow cavities are replaced with fat (yellow bone marrow) and at age 40 years old, composition of our fat and haemopoietic tissue are equal.
But, in some cases extramedullary haemopoiesis can occur in adult if
- bone marrow is no longer functional
- bone marrow cant keep up with the demand for our blood cells.
When extramedullary haemopoiesis occur, we might having some problem or certain disease.
Haematopoiesis sites in disease
Haematopoiesis can take place in the liver, spleen, lymph node, kidney and posterior mediastinum when the bone marrow function is insufficient. Rarely, involvement of other organs including adrenal gland, central nervous system, skin and spine have been described. Extramedullary erythropoiesis is seen where bone marrow is diseased or overwhelmed.
- Diseased bone marrow: Bone marrow diseases like myelofibrosis and bone marrow infiltrations limit the marrow available for haematopoiesis forcing haematopoiesis to extramedullary sites.
- Overwhelmed bone marrow: Patients with chronic haemolytic anaemia and thalassaemias have bone marrow expansion to cope up with increased demand of erythrocytes. Extramedullary erythropoiesis may be seen in patients whose needs are not met with full marrow expansion.
Extramedullary haematopoiesis can cause symptoms including
- Leukoerythroblastic anaemia and the presence of tear drop erythrocytes.
- Symptoms caused by splenomegaly:
- Spinal cord compression (usually thoracic)
- Rare manifestation include effusion due to involvement of the serious membranes and compression by masses arising from the skull and the paranasal sinuses
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