Final answer:
White blood cells are identified by the shape of their nuclei and the presence or absence of cytoplasmic granules.
Step-by-step explanation:
White blood cells (WBCs), also known as leukocytes, are identified microscopically by the shape of their nuclei and the presence or absence of cytoplasmic granules. The two main categories of WBCs are granulocytes and agranulocytes. Granulocytes, which include neutrophils, eosinophils, and basophils, contain visible granules within their cytoplasm. The agranulocytes, which encompass monocytes and lymphocytes, typically do not contain these granules. Contrary to red blood cells, which lack nuclei and contain hemoglobin, WBCs have nuclei and do not contain hemoglobin, allowing for their varied functions in the immune response.
The granules in the cytoplasm serve as a distinguishing feature when using histologic staining techniques like the Wright-Giemsa stain. This staining method colors the cytoplasm of granulocytes and their granules in various shades, facilitating the identification and differentiation of WBC types. Agranulocytes have a lack of granules, which differentiates them from granulocytes when viewed under a microscope after staining.
Understanding the morphology of white blood cells and their role in the body's defense mechanisms is crucial in medical and biological studies. Microscopic examination of WBCs provides vital information for diagnosing and treating various diseases.