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Question 335
Physiology → Haematology
Classification
Question
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A granulocyte contains coarse cytoplasmic granules that stain purple-blue with methylene blue. Which pair of substances is characteristic of these granules?
Question Stem
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Options
A
Histamine and heparin
B
Fibrinogen and factor XIII
C
Serotonin and calcium
D
PDGF and VEGF
E
Interleukin-4 and platelet-activating factor
Explanation
The staining characteristics identify a basophil. Basophilic granules are coarse, stain purple-blue with methylene blue and contain histamine and heparin.
Option Validity
B) Fibrinogen and factor XIII are constituents of platelet alpha granules rather than basophil granules.
C) Serotonin and calcium are found among platelet dense-granule contents rather than forming the characteristic basophil pair.
D) PDGF and VEGF are platelet alpha-granule constituents.
E) Eosinophils release cytokines including interleukin-4 and platelet-activating factor; this is not the characteristic basophil-granule pair.
Further Reading
Saxena R. Textbook for MRCOG-1. Chapter 3: Physiology – Haematology. p.69.