Blood Cell Formation

Terms of Blood Cell Lineages

1. Erythropoiesis - a complex physiological process to maintain oxygen level in the body through production of red blood cells 2. Granulopoiesis - The process by which committed hemopoietic progenitor cells to develop into granulocytes under the influence of various growth factors and cytokines 3. Lymphopoiesis - T lymphopoiesis requires the continuous recruitment of blood-borne progenitors making their way from the BM and entering the thymus through vessels near the CMJ. 4. Monopoiesis - The process that generates new, mature blood cells. 5. Thrombopoiesis - Platelet production requires the differentiation of hematopoietic stem cells within the bone marrow into megakaryocytes (MKs), the platelet progenitor cell.

Theories of Hemopoiesis and Cell Lineages

1. Unitarian or monophyletic 2. Dualistic or Diphyletic a. Monocytes & lymphocytes -> lymphoblast b. Granular leukocytes & erythrocytes -> myeloblast 3. Polyphyletic -> each blood cell has it's own stem cell

Two Types of Marrows

1.Yellow Bone Marrow 2.Red Bone Marrow

VIP

The most important site of hemopoiesis in adult mammal is the bone marrow Initially scientist felt that the bone marrow only gave rise to: erythrocytes platelets, and granular leukocytes

Blood Cell Formation

• Hemopoiesis is the process of blood cell formation. The site where blood cells are formed is referred to as hemopoietic tissues or organs. • The principal hemopoietic organs are the: 1. Bone marrow 2. Spleen 3. Lymph nodes 4. Thymus 5. liver

Blood cells Divided - 2 Categories

•Mononuclear Leukocytes = Lymphoid elements •Erythrocytes = Myeloid elements •Platelets = Myeloid elements •Granular Leukocytes = Myeloid elements