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Question 355
Physiology → Haematology
Classification
Question
SSBAQuestion Header
A granulocyte population increases during a parasitic infection and also participates in allergic and mucosal immune responses.
Question Stem
Which additional set of features most accurately identifies this cell?
Options
A
Multilobed nucleus, fine granules and histamine-heparin storage
B
Kidney-shaped nucleus, agranular cytoplasm and transformation into tissue macrophages
C
Coarse purple-blue granules containing histamine and heparin
D
Agranular cytoplasm with immunoglobulin production as its defining function
E
Bilobed nucleus, coarse eosin-staining granules and release of interleukin-4 and platelet-activating factor
Explanation
Eosinophils have a bilobed, spectacle-shaped nucleus and coarse granules that stain pink or red with eosin. They attack parasites, participate in mucosal immunity and allergic responses, and release cytokines including interleukin-4 and platelet-activating factor.
Option Validity
A) A multilobed nucleus and fine granules characterise neutrophils, while histamine and heparin are associated with basophilic granules.
B) A kidney- or bean-shaped nucleus, agranular cytoplasm and subsequent transformation into tissue macrophages describe monocytes.
C) Coarse purple-blue granules containing histamine and heparin characterise basophils.
D) Lymphocytes are agranulocytes; B lymphocytes are associated with humoral immunity and immunoglobulin production rather than the described parasitic and allergic profile.
Further Reading
Saxena. Textbook for MRCOG-1. Physiology - Haematology - Eosinophils, p.69.