The monocyte is the largest cell in a blood smear. Adhere to injured regions of vessels and help in clotting of the blood. May release clotting factors to enhance fibrin formation. Can release fibrinolysin to dissolve clots. Contain serotonin and other vasomotor agents causing vascular contraction.
Platelets appear indistinguishable at low magnification from debris on blood smears.
Tend to be found in groups. In both smears and sections of bone marrow look for the largest cells at 10x. These will be megakaryocytes. Compare these cells in sections with those in the bone marrow smear. B. Myeloid Tissue 1.