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Question 298
Physiology → Haematology
Classification
Question
SSBAOptions
Explanation
The morphology identifies a monocyte, the largest leucocyte. After several days in the circulation, monocytes migrate into tissues and become macrophages; in chronic infections they may also contribute to multinucleated giant-cell formation.
Option Validity
A) Erythrocytes represent a separate blood-cell lineage and mature circulating erythrocytes are non-nucleated. does not describe monocytes converting into red cells.
B) Platelets are fragments derived from megakaryocytes rather than monocytes. Monocytes instead undergo tissue migration and macrophage differentiation.
C) Eosinophils are a separate granulocyte population with characteristic coarse eosin-staining granules and a bilobed nucleus. Monocytes do not differentiate into eosinophils.
D) B lymphocytes are a separate lymphocyte population associated with humoral immunity and immunoglobulin production. The fate assigned to circulating monocytes is tissue macrophage formation.
Further Reading
Saxena. Textbook for MRCOG-1. Physiology - Haematology - Monocytes, p.70.