Blood

Due to their biconcave disc shape, erythrocytes appear to have a pale center. Small lymphocytes are roughly the same size as erythrocytes (7-8 microns). Platelets are cytoplasmic fragments of bone marrow megakaryocytes. Identify the three types of granulocytes: Neutrophil nuclei usually consist of 3 to 5 lobes, and the cytoplasm holds small purple granules. Eosinophils have a characteristic bilobed nucleus and large, red cytoplasmic granules. Basophils possess large basophilic granules often covering the bilobed. UCLA Histology Collection.