• Focusing on a region near the end of the slide where the smear is relatively thin and cell morphology is good.
• Note that most of the cells present are mature red and white blood cells like those in the smear of circulating blood.
• What could have caused the empty circular areas that are seen?

Identify megakaryocytes (Fig. 13-11) and note their very large, polyploid nuclei.

Give three ways in which megakaryocytes differ from the other types of leukocytes.

Look for erythrocyte precursors (Fig. 13-5), including

• Proerythroblasts, and
• Normoblasts of different stages (early, intermediate, and late)
• Reticulocytes can only be distinguished from mature erythrocytes by using a special stain for their RNA content (Fig. 13-5)..

Look for granulocyte precursors (Fig. 13-8):

• Myelocytes,
• Metamyelocytes, and
• Stab cells.

In a bone marrow transplant, what cells are transplanted and what is the goal of the procedure?

Clinical note: Leukemias are malignancies arising from the hemopoietic precursors of leukocytes and are classified as lymphocytic leukemia or myelogenous leukemia, depending on whether lymphocytes or granulocytes are involved.

Next is the muscle unit.