Hemoglobin Synthesis

 blood transfusion 

     A blood transfusion is a routine medical procedure in which blood is given from a donor through a small tube placed in a vein in the arm.This potentially life-saving procedure helps replace blood lost through surgery or injury. Blood transfusions are also useful when disease prevents the body from making blood or some of its components properly increase.Transfusion usually proceeds without complications. When complications do occur, they are usually mild.Blood transfusion is performed for various reasons, such as surgery, injury, illness, and hemorrhagic diseases.

     Blood has several component such as erythrocytes carry oxygen and help to remove waste products.Leukocytes help your body fights with infection.Plasma is the liquid part of blood.Platelets help blood clot properly.Blood transfusion provides a part of the necessary blood, but the most generally transfused is red blood cells. You can receive all blood, including all components, but all blood transfusion is not common. Although blood transfusions are generally considered safe, there are risks of complications. Mild and rarely severe complications may occur during the transfusion or for a few days or longer after the transfusion.A more common reaction is an allergic reaction that causes hives, itching, and fever.

         

     However , blood transfusion is really vital to anemia patients . The doctor may use this procedure to manage and treat their specific form of anemia such as Sickle cell anemia. This condition affects hemoglobin and distorts the shape of red blood cells. Blood transfusions are especially helpful in critical situations. Doctors can use blood transfusions to treat pain, chest problems, leg pain, and to prevent strokes.Aplastic anemia when the bone marrow does not make enough blood cells, blood transfusions help prevent infection, bleeding, and fatigue.Thalassemia for people with this condition, when the body doesn't make enough normal hemoglobin, a blood transfusion helps the body keep the oxygen-carrying blood.

    There are a few procedures before the transfusion process occurs such as First, the doctor determines the type of transfusion needed and tests the patient's blood to determine blood type. We need this information to ensure we find the right transfusion partner.A health care provider uses a needle to insert an intravenous (IV) line into a blood vessel to allow new blood or blood products to flow into a person's veins.Doctors closely monitor people receiving blood transfusions for side effects. Once the transfusion is complete, remove the IV line. The duration of transfusions varies. This depends, among other things, on the amount of blood a person needs and the types of blood products required.For anemia, red blood cell transfusions are given, which take longer than plasma or platelet transfusions. The usual duration of such a procedure is about 4 hours.

        

        

Do you ever heard about haemopoiesis??

Haemopoiesis is the process through which all the blood and plasma cellular components are produced. It occurs inside the haemopoietic system, a collection of organs and tissues that includes the bone marrow, liver, and spleen.

WHAT IS BONE MARROW? 

The interior of most bones has a soft, spongy tissue with numerous blood veins. Red and yellow bone marrow are the two different colours. Blood stem cells that can develop into red blood cells, white blood cells, or platelets are found in red bone marrow. Stem cells that can develop into cartilage, fat, or bone cells are found in the yellow bone marrow, which is primarily constituted of fat.

FUNCTION OF BONE MARROW?

Almost every component of your blood is created in your bone marrow. Along with white blood cells and platelets, it is in charge of producing billions of red blood cells every day. Additionally, fat that can be converted into energy is stored in the bone marrow.

PROCESS OF HEMOPOIESIS

• It is start with pluripotential stem cells
• This cells will be divided into myeloid progenitor cells and lymphoid progenitor cells
• Myeloid progenitor cells will further divide into red blood cell, white blood cell, and platelet while lymphoid progenitor cell will divide into lymphocytes (B cell, T cell and Natural killer cell)

DEVELOPMENT OF HAEMOPOIESIS

The sites of haemopoiesis develop in the fetus from 0 to 2 months of age in the yolk sac, and from 2 to 7 months of age in the liver and spleen, until 2 weeks after delivery, respectively. However, when the bone marrow has finished developing, which takes place between the ages of 5 and 9 months following conception, haemopoiesis may take place in the foetus's bone marrow. Extramedullary haemopoiesis refers to this phase because it is the initial stage of blood synthesis in the human body. In the human body, it is the initial phase of blood production.

The majority of the red blood cells, white blood cells, and platelets are created from stem cells in the bone marrow during the baby and child stage, which is when medullary haemopoiesis takes place. At this stage, red marrow, which is typical of this period, fills the bulk of the bones in the babies' skeletal system.

By the time a person reaches the age of 40, however, the bone marrow cavities have been replaced by yellow bone marrow, which is mostly made up of fat, with the proportions of fat and hemopoietic tissue being equal. Adults may have extramedullary haemopoiesis if their bone marrow is compromised or unable to produce enough blood cells to meet their needs. The result of this condition is that the liver and spleen will enlarge.

 

The summary of haemopoiesis cycle

Let's Know More About Erythropoiesis!

WHAT IS 

ERYTHROPOIESIS?

The process of producing blood-circulating cells is known as erythropoiesis. The process through which red blood cells are made is called erythropoiesis. To put it another way, the process of creating red blood cells is closely controlled to ensure that tissues receive an adequate amount of oxygen.

WHERE ARE THE SITES OF RED BLOOD CELLS BEING PRODUCED?

The marrow of some bones constantly produces red blood cells. As previously mentioned, the marrow spaces of the vertebrae, ribs, breastbone, and pelvis are the primary sites of red cell generation, or erythropoiesis. The kidney is the primary infrarenal location of erythropoiesis production, whereas the liver is the primary extrarenal site while brain and uterus take part in the production but produces only little amount. In the kidney, interstitial fibroblasts work closely with the proximal convoluted tubule and peritubular capillary to create erythropoietin. Additionally, the liver's perisinusoidal cells generate it. The body ensures that there is a sufficient amount of the hormone erythropoietin, which is produced by the kidney, to allow for the production of red blood cells. The erythroblast, a nucleated cell that lacks haemoglobin, is the fundamental progenitor from which the red blood cell is produced in the bone marrow. Multiple successive cell divisions lead to growth. 

Throughout life, erythropoiesis takes place at several sites. It takes place in the yolk sac in the very young developing fetus. From 2 to 5 months of pregnancy, it develops in the liver and spleen before settling about 5 months of pregnancy in the bone marrow. The bone marrow of the majority of children's bones may support erythropoiesis. Adults, on the other hand, only experience it in the proximal femur, ribs, sternum, sacrum, and bone marrow of the vertebrae. Extra medullary haematopoiesis may result from insufficient erythropoiesis in the bone marrow.

WHAT ARE THE FACTORS AFFECTING ERYTHROPOIESIS? 

✅ Tissue Oxygenation:

Red blood cells must be healthy and in sufficient numbers for your body to receive enough oxygen, which is a condition known as anemia. The main causes of anemia are blood loss, a lack of red blood cell production, and high levels of red blood cell breakdown. There are many different forms of anemia, including iron-deficiency anemia, pernicious anemia, hemo-lytic anemia, and aplastic anemia, which causes the immune system's stem cells to be attacked in the bone marrow that can be classified under bone marrow destruction whereas hypoxia, the production of mature red blood cell from the bone marrow is stimulated by the systemic increase in erythropoietin levels brought on by hypoxia.

Anemia

Bone Marrow Destruction

Hypoxia

✅ Vitamins:

Erythropoiesis is the process by which new red blood cells are produced by replacing old erythrocytes with new ones, which are phagocytosed and destroyed on a daily basis. Elements such as vitamin B12,iron, and folate play important roles in the process of producing red blood cells. As a result, erythroblasts require folate and vitamin B12 to proliferate during differentiation. A lack of folate and vitamin B12 causes erythroblast apoptosis, resulting in anemia from erythropoiesis not functioning because haemoglobin synthesis requires an excessive amount of iron. With haemoglobin breakdown from destroying the old erythrocytes, the iron is used all over again. Many newly discovered proteins play a role in nonheme iron absorption, storage, and cellular export, as well as iron uptake and usage in erythroblasts. Erythroblast heme levels regulate iron and globin synthesis, so iron deficiency causes anemia by slowing production rates, which results in smaller, less hemoglobinized erythrocytes. Other than the vitamin mentioned above, these molecules are also involve in the making of red blood cell which are vitamin C, a coenzyme called pyridoxine is involved in the condensation of succinyl-CoA and glycine , riboflavin and pantothenic acid involved in the production of heme, which is necessary for both cell growth and division and the production of iron for red blood cells.

✅ Proteins:

For the human body to maintain the normal level of erythropoiesis for the normal rate of globin formation, an adequate protein diet is totally necessary. It is by eating food which is rich with protein. 

✅ Hormones:

Red blood cell regulation involves hormones like testosterone, growth hormone, cortisol, and adrenocorticotrophic hormone.

✅ Minerals and Metals:

The production of blood during erythropoiesis depends on iron. The transferrin carrier, transferrin receptor endosomal cycle, and appropriate mitochondrial iron consumption are essential for the best iron supply. Different kinds of anemia, including those involving iron, copper, cobalt, nickel, and manganese, are caused by iron and iron protein shortages. As a result of binding to transferrin, the oxygen and iron that are combined during absorption are then transported into the plasma of the blood. In addition, all bodily cells need iron and transferrin as needed since they are used to make haemoglobin, which is then stored in the liver, spleen, and bone marrow.

✅ Other Factors:

According to the relationship between menstruation and erythropoiesis, haemoglobin and iron concentrations dropped during menstruation and further reduced in the ovulation, but haemoglobin rose. Due to anemia, which can result from significant menstrual bleeding, heavy periods cause long-term blood loss. Thus, erythropoiesis can also be affected by menopause, exercise, excitement, and pregnancy.

REFERENCES:

Erythropoiesis - an overview | ScienceDirect Topics. (n.d.). Www.sciencedirect.com. https://www.sciencedirect.com/topics/neuroscience/erythropoiesis

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Component of blood, morphology and functions of each blood cell

        Blood is the primary transport medium that is responsible for supplying nutrients and oxygen to the cells in the body. The three functions of the blood are transportation, regulation and protection. The blood is about 45% formed fragments and 55% blood plasma. The formed elements are the cellular components of the blood while the liquid part is plasma. Blood consists of four major components :

 

1)    Red Blood Cells (Erythrocytes)

2)    White Blood Cell (Leukocytes)

3)    Platelets (Thrombocytes)

4)    Plasma

 

ERYTHROCYTES

        First and foremost the erythrocytes or also known as the red blood cell. It is a biconcave disc shaped cell that contains oxygen carrying protein called haemoglobin. The haemoglobin is what gives the red colour of the blood. The biconcave discs diameter is around 7-8μm and the function of its shape is to increase the surface area for oxygen and carbon dioxide diffusion. Erythrocytes does not have a nucleus and it cant reproduce. The red blood cell is produced in the bone marrow. The structure is highly elastic and are able to squeeze through capillary walls without rupturing. Red blood cells function is to transport oxygen to the tissues and transport carbon dioxide to the lungs. The RBC only live about 120 days because of the squeezing through the capillaries. It is then destroyed within the spleen and liver.

 

LEUKOCYTES

 

        Next, leukocyte or also known as white blood cell makes up about 1% of the volume in blood. Unlike the erythrocyte the leukocyte have nucleus and a bunch of other organelles but they do not have haemoglobin thus making it colourless. The white blood cell is either granular or agranular. Granular leukocyte are neutrophils, eosinophils and basophils where it contains granules. While agranular leukocytes are lymphocytes and monocytes where it does not contain granules. The function of leukocyte is as defence mechanism of the body and is part of the immune system to fight infections and diseases.

 

NEUTROPHIL

 

        Neutrophils are the most abundant type of granulocyte and makes up to 70% of white blood cells. They are smaller than the other granular leukocytes with the diameter of 12-15μm . The nucleus has up to two to five lobes that are connected by very thin strands of fine filament. Older neutrophils have different shaped nuclear lobes and more number of lobes. The cytoplasm of the cell is clear and contains pink coloured granules. Immature neutrophils have a horseshoe shaped nucleus and it is called a band cell. The functions of neutrophils are to fight against bacterial infection and inflammation. It is also the first responders to bacterial infection. Large number of cells are involved in combating foreign material and death of bacteria and cells causing pus formation.

  

 

EOSINOPHIL

 

        Eosinophils are also called acidophils. It is a specialised cell that is pretty rare in our blood.It has the same size as neutrophil. The structure of the eosinophil have two nucleus and it is a bilobed nucleus. The cytoplasm is filled with pink granules. The functions of the eosinophil are to combat effects of histamine in allergic reactions, phagocyte antigen and destroy parasitic worms. They are also able to modulate inflammatory process. Mostly they are important to deal with allergy. When there are many eosinophils in the blood it indicates that the body is having an allergic reaction.

 

BASOPHIL

 

        Basophil are the rarest of all leukocyte with only less than 1% in the blood count. The basophil has two nucleus with large cytoplasmic granules and they appear deep blue purplish. The nucleus is hard to see because it is overlapped with granules. A high count of basophil may indicate leukemias and cancers while a low count might indicate pregnancy and ovulation. The function of basophil are to deal with allergic reaction related to histamine.

 

MONOCYTE

 

        Monocyte is the biggest leukocyte in our blood.  The monocyte is about 12-20 micrometer in diameter twice the size of a red blood cell. The monocyte has a kidney-shaped nucleus with a transparent cytoplasm with ground glass appearance. The blood is just a temporary place for monocytes that will later go to the tissues where they will enlarge and become macrophages. A high count of monocyte may indicate bacterial infection, inflammation and stress. The functions of monocytes are for phagocytosis function to bind the pathogen and present them to T-cells. 

 

LYMPHOCYTE

 

        Lymphocyte commonly appear around 20% - 40% in our blood. The size is smaller than other leukocytes but larger than red blood cell. Lymphocytes have transparent cytoplasm, with round and large nucleus occupying most of cytoplasm. There are three types of lymphocyte firstly the T cells, they coordinate the immune system, defence against intracellular bacteria and kill virus infected cells. Other than that, B cells that make antibodies that bind to bacteria and destroy them. Finally, Natural Killer Cells (NKC), they kill cells that are infected with virus or becoming cancerous by nature.

 

THROMBOCYTES

 

        Another name for thrombocytes is platelet. Platelets break off from megakaryocytes in red bone marrow and enter the blood. In each microliter of blood there are between 150,000 and 400,000 platelets present. Each platelet is irregularly disc shaped around 2-4 μm in diameter. Mostly oval in shape and do not have nucleus. The function of platelet is to form platelet plug in homeostasis and release chemicals that promote vascular spasm and blood clotting. It is also a natural source of growth factor. 

Written by Muhammad Fariz

Reference :

 

1.     “Basophils: What They Are and What They Do.” WebMD, 8 Apr. 2021, www.webmd.com/a-to-z-guides/what-are-basophils.

2.     @ClevelandClinic. “Eosinophilia: Definition, Symptoms, Causes and Treatment.” Cleveland Clinic, my.clevelandclinic.org/health/diseases/17710-eosinophilia.

3.     “What Do Your Blood Platelets Do?” Verywell Health, 31 Aug. 2022, www.verywellhealth.com/thrombocyte-what-is-a-thrombocyte-797228.

4.     @ClevelandClinic. “Monocytes: A Type of White Blood Cell — What Are Normal Ranges?” Cleveland Clinic, my.clevelandclinic.org/health/body/22110-monocytes. 

5.     @ClevelandClinic. “What Are Neutrophils? What Can Cause High or Low Neutrophil Count.” Cleveland Clinic, my.clevelandclinic.org/health/body/22313-neutrophils.

6.     @ClevelandClinic. “Lymphocytes: Function, Definition, Levels and Ranges.” Cleveland Clinic, my.clevelandclinic.org/health/body/23342-lymphocytes. 

7.     https://www.kenhub.com/en/library/anatomy/erythrocytes