Physiology · Blood

RBC functions and erythrocyte indices

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Definition

  • The red blood cell (erythrocyte) is a circular, non-nucleated, biconcave disc.
  • Normal count:
    • Adult males: 4.5 to 6 million/mm3 (average 5.2 million).
    • Adult females: 4 to 5.5 million/mm3 (average 4.7 million).
  • Red cells are destroyed by the tissue macrophage system.

RBC lifespan120 days

Red Cell Structure and Dimensions

Red cell dimensions

Parameter

Shape

Value
Biconcave

Diameter

Value
7.5 µm (7 to 8 µm)

Thickness

Value
2 µm at periphery, 1 µm at center

Surface area

Value
140 µm²

Volume

Value
87 µm³ (78 to 94 µm³)

Red cell shape, side view and surface view