Table 3. Membrane areas for transport and metabolism in myocardium.

Component	Area, cm2/g
RBC (20% Hct)	210*
Capillary wall (full recruitment)	500†
Sarcolemma	2,500‡
Sarcoplasmic reticulum	10,000‡
Mitochondrial cristae	80,000§

^*Calculated from 150-μm² surface area per 90-μm³ volume per red blood cell (RBC) for a Hct of 20%, capillary diameter of 5.2 μm, and density of 3,000 capillaries/mm² in parallel, giving a capillary volume of 0.063 ml/g.

^†Bassingthwaighte et al. (8);

^‡Page et al. (34);

^§Page and McCallister (33).