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By the time a person reaches the age of 40, however, the bone marrow cavities have been replaced by yellow bone marrow, which is mostly made up of fat, with the proportions of fat and hemopoietic tissue being equal.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