Hematopoiesis (Power Point Presentation)

Quick notes on Hematopoiesis and brief into about the types of cells are forming during the process.
For UG and PG students.
Different colors, themes and video is used to make it more interesting and easy to go through the contents.

1. PRANJAL SHARMA 20-PZO-016 HEMATOPOIESIS

2. Hematopoiesis Definition Hematopoiesis is the production of all of the cellular components of blood and blood plasma. It occurs within the hematopoietic system, which includes organs and tissues such as the bone marrow, liver, and spleen. Simply, hematopoiesis is the process through which the body manufactures blood cells.

3. There are three distinct lineages of blood cells: Erythroid Lineage , which consists of reticulocytes and erythrocytes (red blood cells). Lymphoid Lineage , which consists of lymphocytes (B and T cells) as well as natural killer cells. Myeloid Lineage , which consists of macrophages, dendritic cells, granulocytes, and megakaryocytes, among others.

4. The Process of Hematopoiesis The rate of hematopoiesis depends on the body’s needs. The body continually manufactures new blood cells to replace old ones. About 1 percent of the body’s blood cells must be replaced every day. White blood cells have the shortest life span, sometimes surviving just a few hours to a few days, while red blood cells can last up to 120 days or so. The process of hematopoiesis begins with an unspecialized stem cell. This stem cell multiplies, and some of these new cells transform into precursor cells. These are cells that are destined to become a particular type of blood cell but are not yet fully developed. However, these immature cells soon divide and mature into blood components, such as red and white blood cells, or platelets. Although researchers understand the basics of hematopoiesis, there is an-ongoing scientific debate about how the stem cells that play a role in hematopoiesis are formed.

5. Stages of Hematopoiesis Mesoblastic stage -first month of embryonic life where cells are formed outside the embryo in the mesenchyme of the yolk sac. Hepatic stage -by the 6th week Medullary stage- by the 5th month blood cell formation occurs in the bone marrow. MarrOW primitive stem cells & Committed progenitor cells are confined -Spleen & lymph nodes secondary lymphoid tissue for lymphocyte development an d differentiation .

6. Stages of Hematopoiesis Mesoblastic stage -first month of embryonic life where cells are formed outside the embryo in the mesenchyme of the yolk sac. Hepatic stage -by the 6th week Medullary stage- by the 5th month blood cell formation Occurs in the bone marrow. MarrOW primitive stem cells & Committed progenitor cells are confined -Spleen & lymph nodes 2ndary lymphoid tissue for lymphocyte development and differentiationn.

7. Types of cells involved in the process Each type of blood cell follows a slightly different path of hematopoiesis. All begin as stem cells called multipotent hematopoietic stem cells (HSC). From there, hematopoiesis follows two distinct pathways. Trilineage hematopoiesis refers to the production of three types of blood cells: platelets, red blood cells, and white blood cells. Each of these cells begins with the transformation of HSC into cells called common myeloid progenitors (CMP). After that, the process varies slightly. At each stage of the process, the precursor cells become more organized:

8. Red blood cells and platelets Red blood cells: CMP cells change five times before finally becoming red blood cells, also known as erythrocytes. Platelets: CMP cells transform into three different cell types before becoming platelets .

9. White blood cells There are several types of white blood cells, each following an individual path during hematopoiesis. All white blood cells initially transform from CMP cells into to myeoblasts. After that, the process is as follows: Before becoming a neutrophil, eosinophil, or basophil, a myeoblast goes through four further stages of development. To become a macrophage, a myeoblast has to transform three more times.

10. T cells and B cells To produce lymphocytes, MHCs transform into cells called common lymphoid progenitors, which then become lymphoblasts. Lymphoblasts differentiate into infection-fighting T cells and B cells. Some B cells differentiate into plasma cells after exposure to infection.

11. Factors Regulating Erythropoiesis. The major growth factors regulating in vivo erythropoiesis are granulocyte colony-stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin- (IL-) 3, stem cell factor (SCF), IL-1, IL-6, IL-4, IL-9, IL-11, insulin growth factor-1 (IGF-1), and erythropoietin (EPO). Also, Vitamin B12 ,Folic Acid, Vitamin C, Iron ,Copper ,Calcium, Bile salt ,Cobalt and Nickel.

12. T cells and B cells To produce lymphocytes, MHCs transform into cells called common lymphoid progenitors, which then become lymphoblasts. Lymphoblasts differentiate into infection-fighting T cells and B cells. Some B cells differentiate into plasma cells after exposure to infection.

13. Facts of Hematopoiesis In a healthy adult person, about 10 11 –10 12 new blood cells are produced daily to keep steady state levels in the blood circulation. There are 150 Billion red blood cells in one ounce of blood . There are 2.4 Trillion red blood cells in one pint of blood . The human body manufactures 17 million red blood cells per second. ... A red blood cell is around 7 microns in size. We can store blood for 42 days if we do not freeze it. Frozen blood can be stored ten years, but freezing blood is a poor way of storing it. Generally speaking, we store blood in the refrigerator, where we can store it for up to 42 days.

14. Significance of Erythropoiesis Erythropoiesis, the development of red blood cells, is a tightly regulated process for maintaining sufficient oxygen delivery to tissue. Oxygen delivery is proportional to the concentration of oxyhemoglobin (the hemoglobin level x oxygen saturation) and cardiac output.

15. C onclusion

16. Possible Question from the Chapter Explain the process of Hematopoisis. What are the different types of blood cell? What is the major site of blood production in adults? Factors responsible for hemopoisis. How many types of blood formation lineages are their? Write the Life span of RBC ,WBC and Platelets Respectively.

17. References https://www.medicalnewstoday.com/articles/319544#hematopoiesis-and-health https://en.wikipedia.org/wiki/Haematopoiesis https://biologydictionary.net/hematopoiesis/ https://www.news-medical.net/life-sciences/Hematopoiesis-Process.aspx Principles of Anatomy and Physiology,Book by Bryan H. Derrickson and Gerard J. Tortora Immunology,Textbook by Barbara Anne Osborne and Janis Kuby