If a blood specimen is mixed too vigorously, which of the following cell types is most likely to be affected?

Mixing a blood specimen too vigorously can lead to the destruction of red blood cells, also known as erythrocytes. This phenomenon is primarily due to mechanical shearing forces that occur during vigorous agitation. Erythrocytes are quite fragile and can be damaged or hemolyzed when subjected to excessive force. When hemolysis occurs, it causes the release of hemoglobin into the plasma, which can interfere with laboratory tests and lead to inaccurate results.

Leukocytes (white blood cells) and platelets (also classified as thrombocytes) are generally less affected by vigorous mixing compared to erythrocytes, as they can withstand more mechanical stress. Although platelets can become activated or aggregated through excessive mixing, the primary concern in terms of cell destruction lies with erythrocytes. Therefore, understanding that erythrocytes are particularly susceptible to damage from vigorous agitation clarifies why this is the correct answer.