Stages of Development of Blood Cells PDF

Stages of Development of Blood Anatomy unit Objectives Understand the composition of whole blood. How to prepare a blood smear. Describe the structure of Erythrocyte. Enlist different types of leucocytes. Explain the differentiation of myeloid and lymphoid stem cells. Discu...

Stages of Development of Blood Anatomy unit Objectives Understand the composition of whole blood. How to prepare a blood smear. Describe the structure of Erythrocyte. Enlist different types of leucocytes. Explain the differentiation of myeloid and lymphoid stem cells. Discuss the development of blood cells in red bone marrow. Composition of Whole Blood Preparing a Blood Smear Blood cells Erythrocytes (RBCs) (Thrombocytes) Erythrocytes (RBCs)    The most abundant cells in the blood. Shape: Flexible, biconcave discs. Size: Diameter: 6-9 μm (average 7.5 μm) Thickness: about 2.5 μm at the rim and only 0 75 μm in the center  LM:   Non nucleated Appear ac dophilic with pale center.  Life span: 1 20 days, then they become engulfed by macrophages. Erythrocytes (RBCs)   Abnormal shape of RBCs may be:   Sickle shape Spherocytosis (biconvex) Abnormal size of RBCs may be:   Diameter \< 6 μm microcytic. Diameter \> 9 μm macrocytic. Types of Human Leucocytes N leukocytes leukocytes 1. Neutrophils 2\. Basophils 3\. Eosinophils 1\. Monocytes 2\. Lymphocytes (Neutrophils)     Percentage: 60-70% of circulating leukocytes. Size: 12-15 μm in diameter Nucleus: segmented, multilobed (2-5 lobes) Cytoplasm: cytoplasmic granules of 2 types:   A S ec f c se dar ran es l , l d n , i in p n , con ac  Life span: 1-4 days (Eosinophils)      Percentage: 2-4% of circulating leukocytes Size: 12-15 μm in diameter Nucleus: bilobed Cytoplasm: characteristic granules: large, acidophilic. Life span: 8-12 days. Leucocytes (Basophils)     Percentage: less than 1% of circulating leukocytes Size: 12-15 μm in diameter Nucleus: divided into 2 irregular lobes rge irregular). Cytoplasm: characteristic specific gr nules: st in purple, few, large, irregularly shaped, overly the nucleus and obscure its shape. They contain histamine and heparin.  Life span: 10-15 days (Lymphocytes)   Percentage: 20 n Size:   Small lymphocytes: same diameter as RBCs μm. Medium and large: 7-15 μm in diameter.  Nucleus:  Small lymphocytes: spherical, highly condensed, and thin rim of cytoplasm.  Large: larger, slightly indented nuclei and more cytoplasm which is slightly basophilic, few azurophilic granules. (Lymphocytes)  Types:   e from the w.     Responsible for h T. Originate from the t l Responsible for cell mediated im. (Monocytes)    Precursor of macrophages. Percentage: 3-8% of circulating leukocytes Size: 15- 20 μm in diameter (the largest cell in blood smear)   Nucleus: large indented, c shaped, or kidney shaped. Cytoplasm: basophilic, many small azurophilic granules  Life span: 3 days Platelets (Thrombocytes)  Blood platelets (thrombocytes) are very small non-nucleated, membrane-bound cell fragments.     Diameter: 2-4 μm Normal count: 150000 to 400000/μL of blood. Life span: about 10 days. In stained smears: Platelets often appear in clumps. Each platelet is discoid with very lightly stained peripheral zone (hyalomere) and darker staining central zone rich in granules (granulomere). Hemopoiesis Hemopoiesis    Means formation and development of bl s. All b d cells are derived from P uripo. They give rise to 2 ges: I. Myeloid stem cells: differentiate into  Colony forming unit Granulocytes-monocytes (CFU-GM): → 1. Neutrophils. 2. Eosinophils. 3   Colony forming unit Erythrocytes (CFU-E): → Erythrocytes. CFU Megakaryocytes (CFU-Meg): → platelets. II\. Lymphoid stem cells: differentiate into  1