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Question 319
Physiology → Haematology
Classification
Question
SSBAOptions
Explanation
packed red blood cells are used in anaemia or blood loss when replacement of plasma clotting factors is not required. This provides red-cell replacement without unnecessary plasma.
Option Validity
A) Serum is plasma without clotting factors and does not provide the required erythrocyte mass. It therefore does not address the red-cell replacement described in the stem.
B) The buffy coat consists mainly of white blood cells and platelets after centrifugation. It is not the component described for replacement of erythrocyte oxygen-carrying capacity.
D) Dense granules are intracellular platelet structures containing substances such as nucleotides, serotonin, phospholipids and calcium. They are not a blood component used for red-cell replacement.
E) Plasma does not supply the erythrocyte mass required in the stem. packed red blood cells when plasma clotting factors are not required.
Further Reading
Saxena. Textbook for MRCOG-1. Physiology - Haematology - Red Blood Cells, p.67.