Outline the formation, structure and function of the adult red blood cell.
Candidates generally provided detailed description of the cell lineage that led up to the
production of the mature red blood cell (RBC), but often omitted to mention those aspects
unique to the RBC that were essential to its functions (e.g. biconcave shape gives the RBC a
greater surface area and shorter distance to central regions, thus optimising diffusion of
gases; the RBC enhanced ability to change shape and travel through narrow capillaries; lack of
organelles maximises space for Hb, etc.). Mention of RBC function often lacked detail (e.g.
restricted to just mentioning “O2 carriage”) or failed to mention, and describe, the RBC’s role
in acid base buffering and HCO3- production.