In the human embryo, the first place of blood formation is the yolk sac. Later in embryonic life, the liver becomes the most important organ for the formation of red blood cells, but it is soon replaced by the bone marrow, which in adulthood is the only source of red blood cells and granulocytes. Red and white blood cells are formed by a series of complex, progressive and successive transformations from primitive stem cells that have the ability to form one of the precursors of a blood cell. Progenitor cells are stem cells that have evolved to the stage where they have been dedicated to the formation of a certain type of new blood cells. There are other organs and systems in our body that help regulate blood cells. The lymph nodes, spleen and liver help regulate the production, destruction and differentiation (development of a certain function) of cells. If you or someone you care about is diagnosed with blood disease, your GP may refer you to a hematologist for further examination and treatment. Blood cells form in the bone marrow. Bone marrow is the soft, spongy material in the middle of the bones. It produces about 95% of the body`s blood cells. Most of the bone marrow of the adult body is located in the pelvic bones, chest bones and bones of the spine. The blood that circulates in the veins, arteries, and capillaries is called whole blood, a mixture of about 55% plasma and 45% blood cells.

About 7-8% of your total body weight is blood. A medium-sized man has about 12 liters of blood in his body, and a medium-sized woman has about nine pints. Leukopoiesis, the process of making leukocytes, is stimulated by various colony-stimulating factors (CSFs), which are hormones produced by mature white blood cells. The development of any type of white blood cell begins with the division of hemopoietic stem cells into one of the following “blast cells”: blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells and platelets. Blood has many different functions, including: thrombopoiesis, the process of making platelets, begins with the formation of megakaryoblasts from hemopoietic stem cells. Without cytokinesis, megakaryoblasts divide into megakaryocytes, huge cells with a large multilobed nucleus. The megakaryocytes then fragment into segments as the plasma membrane inserts into the cytoplasm. White blood cells protect the body from infections. They are much less numerous than red blood cells and make up about 1% of your blood. The other main type of white blood cells is a lymphocyte.

There are two main populations of these cells. T cells help regulate the function of other immune cells and directly attack various infected cells and tumors. B lymphocytes form antibodies, which are proteins that specifically target bacteria, viruses and other foreign substances. Your doctor will explain the purpose and results of the blood tests. Blood consists of 45% red blood cells, less than 1% white blood cells and platelets, and 55% plasma. The American Society of Hematology (ASH) educational book, updated annually by experts in the field, is a collection of articles on current treatment options available to patients. Articles are classified here by type of disease. If you want to learn more about a particular blood disorder, we recommend that you share and discuss these articles with your doctor. The main function of platelets is blood clotting. Platelets are much smaller than other blood cells.

They group together to form lumps or a plug in the hole of a vessel to stop bleeding. The average rate of erythrocyte production in healthy individuals is two million cells per second. Normal production requires adequate amounts of iron, vitamin B12 and folic acid. Vitamin B-12 and folic acid are necessary for the proper development of DNA in erythroblasts. This DNA is responsible for the organization of the hemmolecule, of which iron becomes a component. Good DNA development is also necessary for the reproduction of erythroblasts. A lack of vitamin B12 or folic acid can lead to pernicious anemia. Red blood cells (erythrocytes).

These carry oxygen from the lungs to the rest of the body. Erythropoiesis, the process of producing erythrocytes, begins with the formation of proerythroblasts from hemopoietic stem cells. For three to five days, several stages of development follow, when ribosomes multiply and hemoglobin is synthesized. Eventually, the nucleus is expelled, creating a depression in the middle of the cell. Young erythrocytes, called reticulocytes, which still contain ribosomes and endoplasmic reticulum, pass into the bloodstream and develop into mature erythrocytes after a day or two. The production of red blood cells is controlled by erythropoietin, a hormone produced mainly by the kidneys. Red blood cells begin as immature cells in the bone marrow and are released into the bloodstream after about seven days of maturation. Unlike many other cells, red blood cells have no nucleus and can easily change shape, making them adapt through the different blood vessels in your body. Although the absence of a nucleus makes a red blood cell more flexible, it also limits the life of the cell, as it moves through the smallest blood vessels, damaging the cell`s membranes and depleting its energy supply. Red blood cells survive an average of only 120 days. A.D.A.M., Inc.

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Blood cells formed in the bone marrow begin as a stem cell. A stem cell is the first phase of all blood cells. As the stem cell matures, several different cells grow. These include red blood cells, white blood cells and platelets. Immature blood cells are also called blasts. Some explosions remain in the marrow until maturity. Others travel to other parts of the body to develop into mature, functional blood cells. A complete blood count (BCC) test gives your doctor important information about the type and number of cells in your blood, especially red blood cells and their percentage (hematocrit) or protein content (hemoglobin), white blood cells, and platelets.

The results of a BCC can diagnose conditions such as anemia, infection, and other disorders. Platelet count and plasma coagulation tests (prothombin time, partial thromboplastin time, and thrombin time) can be used to assess bleeding and bleeding disorders. Chemicals in your blood called growth factors control the formation of blood cells. Different growth factors cause blood stem cells in the bone marrow to become different types of blood cells. .