University of Phoenix Material Animations: The Cardiovascular System Hemopoiesis After viewing the animation, answer these questions. 1. Hemopoiesis is the process of blood cell formation, which occurs primarily in the red bone marrow. 2. Hemopoiesis begins with undifferentiated cells called hemocytoblasts. 3. These stem cells give rise to many different cell types that make up the cellular elements of blood. 4. What types of hormones influence the differentiation of the blood stem cells? (CSF’s) Colony Stimulating Factors 5.
What are the two lines of cells that differentiate from the hemocytoblast? The myeloid or the Lymphoid cell line. 6. Which groups of cells arise from each of these lines? The myeloid cell line forms erythrocytes (or red blood cells) and megakaryocytes that form platelets and leukocytes, except for lymphocytes which are produced by the lymphoid cell line. 7. Which cells are produced by the lymphoid cell line? Lymphocytes. 8. Erythropoiesis produces red blood cells. 9. List the steps for red blood cell (erythrocyte) production.
It begins with stimulation of the myeloid stem cells by CSFs to produce a progenitor cell that gives rise to a proerythroblast. The hormone erythropoietin initiates the erythroblast stage which proerythroblasts are stimulated to form erythroblasts. The erythroblast begins to synthesize hemoglobin and gradually decreases in size, giving rise to a normoblast. At this point the nucleus is ejected from the normoblast resulting in a reticulocyte After the reticulocyte enters the blood stream its organelles degenerate at which point it is considered a mature erythrocyte. 0. Thrombopoiesis produces platelets. 11. What is the name for the committed progenitor cell in thrombopoiesis? Megakaryoblast. 12. In response to the hormone thrombopoietin, the megakaryoblast differentiates into a megakaryocyte. 13. Platelets are formed when thousands of small, cell membrane-bound portions of the cytoplasm break away from the parent cell. 14. Leukopoiesis is the formation of white blood cells. 15. The myeloid cell line gives rise to granulocytes (eosinophils, basophils and neutrophils) and monocytes. 16. The lymphoid cell line produces lymphocytes. 7. Eosinophilic myelocytes differentiate into eosinophils. 18. Basophilic myelocytes differentiate into basophils. 19. Neutrophilic myelocytes develop into nutrophils. 20. Monocytes are derived from granulocyte stem cells. 21. Lymphocytes are derived from lymphoid stem cell. 22. The two types of lymphocytes that develop are B- and T- lymphocytes. Hemoglobin Breakdown After viewing the animation, answer these questions. 1. What happens to the hemoglobin released by the rupture of old red blood cells? It is ingested by macrophages. 2.
The globin chains are broken down to individual amino acids that are metabolized or used to build new proteins. 3. What is released from the heme? Iron 4. The remaining structure of the heme goes through a two-step process, being converted to the following two products sequentially biliverdin, which is then converted into biliruben. 5. What plasma protein transports the iron? Transferrin. 6. Where is iron transported for storage (two locations)? Liver and Spleen 7. Where is iron transported to make new hemoglobin? Red bone marrow 8. What plasma protein transports free bilirubin?
Albumin. 9. Where is it transported? The liver. 10. Liver cells make conjugated bilirubin which is excreted as part of the bile into the small intestine. 11. Intestinal bacteria convert bilirubin into bilirubin derivatives, which contribute to the color of feces. 12. Some of the bilirubin derivatives are absorbed into the blood and excreted from the kidneys in the urine. (This product is urochrome, which gives urine its yellow color. ) Reference Broyles, R. B. (2012). Workbook to accompany anatomy & physiology revealed version 3. 0. New York, NY: McGraw-Hill. Adapted with permission.