4 Megakaryocyte maturation Platelets arise from the megakaryocyte. Megakaryocytes are among the largest cells in the body and mature by a unique process called endomitosis. In endomitosis, the nucleus is duplicated but there is no cell division, resulting in a polyploid cell. Megakaryocyte nuclei may have from 2 to 32 lobes and, in unusual cases, may have up to 64 lobes. Megakaryocytes develop copious cytoplasm, which differentiates into platelets. Platelets have several types of granules that can be visualized by electron microscopy. The granules are highly specialized. Refer to a hematology textbook for further discussion. FIGURE 4–1 Megakaryocyte sequence—megakaryoblast MK-I. Megakaryoblast (MK-I) FIGURE 4–2A Megakaryoblast, MK-I—bone marrow (×1000). FIGURE 4–2B Megakaryoblast, schematic. Size: 10-24 μm Nucleus: Round Nucleoli: 2-6 Chromatin: Homogeneous, loosely organized Cytoplasm: basophilic Granules: Absent by Wright stain N/C RATIO: 3:1 Reference interval: Bone marrow: 20% of megakaryocyte precursors in bone marrow Peripheral blood: 0% Note: The megakaryoblast appears similar to the myeloblast and pronormoblast, and identification by morphology alone is not advisable. FIGURE 4–3 Megakaryocyte sequence—promegakaryocyte (MK-II). Promegakaryocyte (MK-II) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hematopoiesis Precursor lymphoid neoplasms Variations in size and color of erythrocytes Erythrocyte maturation Variations in shape and distribution of erythrocytes Diseases affecting erythrocytes Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Hematology Atlas Jun 12, 2016 | Posted by admin in HEMATOLOGY | Comments Off on Megakaryocyte maturation Full access? Get Clinical Tree
4 Megakaryocyte maturation Platelets arise from the megakaryocyte. Megakaryocytes are among the largest cells in the body and mature by a unique process called endomitosis. In endomitosis, the nucleus is duplicated but there is no cell division, resulting in a polyploid cell. Megakaryocyte nuclei may have from 2 to 32 lobes and, in unusual cases, may have up to 64 lobes. Megakaryocytes develop copious cytoplasm, which differentiates into platelets. Platelets have several types of granules that can be visualized by electron microscopy. The granules are highly specialized. Refer to a hematology textbook for further discussion. FIGURE 4–1 Megakaryocyte sequence—megakaryoblast MK-I. Megakaryoblast (MK-I) FIGURE 4–2A Megakaryoblast, MK-I—bone marrow (×1000). FIGURE 4–2B Megakaryoblast, schematic. Size: 10-24 μm Nucleus: Round Nucleoli: 2-6 Chromatin: Homogeneous, loosely organized Cytoplasm: basophilic Granules: Absent by Wright stain N/C RATIO: 3:1 Reference interval: Bone marrow: 20% of megakaryocyte precursors in bone marrow Peripheral blood: 0% Note: The megakaryoblast appears similar to the myeloblast and pronormoblast, and identification by morphology alone is not advisable. FIGURE 4–3 Megakaryocyte sequence—promegakaryocyte (MK-II). Promegakaryocyte (MK-II) Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hematopoiesis Precursor lymphoid neoplasms Variations in size and color of erythrocytes Erythrocyte maturation Variations in shape and distribution of erythrocytes Diseases affecting erythrocytes Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Hematology Atlas Jun 12, 2016 | Posted by admin in HEMATOLOGY | Comments Off on Megakaryocyte maturation Full access? Get Clinical Tree
