Histology Guide

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Chapter 8 - Hematopoiesis

Hematopoiesis is the formation of blood cell components. It occurs in the bone marrow of adults.

Bone Marrow

Bone marrow is the primary site of new blood cell production in adults. It is composed mainly of hematopoietic cells, adipose cells, and supportive stromal cells.

Erythropoiesis

Erythropoiesis is the formation of red blood cells (erythrocytes). The cells undergo a series of changes related to the synthesis and accumulation of hemoglobin. Granules are never seen in the lineage of red blood cells.

The large number of extruded nuclei are removed by macrophages.

Granulopoiesis

Granulopoiesis is the development of granulocytes - neutrophils, eosinophils, and basophils. Key events in the maturation of granulocytes are the production of azurophilic granules, specific granules, and nuclear lobulation.

Thrombopoiesis

Thrombopoiesis is the development of platelets. The largest cells found in bone marrow are megakaryocytes which give rise to platelets.

Plasma Cell

Plasma cells are mature B lymphocytes that produce large quantities of antibodies. Normally, few are found in bone marrow.