Figure 4.

The correlation between RBC membrane area and cell volume. (a) Results of simultaneous determinations of RBC membrane area and cell volume extracted from Fig. 5 of (22) are shown. This figure also contains the regression line (full line) and the line of constant sphericity index (dashed line). The latter is equivalent to the line of constant reduced volume. (b) The dependence of the reduced volume v divided by its average ($\overline{v}$, defined by taking in Eq. 3$V=\overline{V}$ and $A=\overline{A}$) on the relative membrane area a, obtained by solving Eq. 4 with f_G defined by Eq. 20. Calculations are presented for the model parameters used for Fig. 1. (c) The dependence of the relative membrane area $\left(A/\overline{A}\right)$ on relative volume $\left(V/\overline{V}\right)$, obtained by Eq. 22. The dashed line is the line with constant reduced volume. The full line that matches it (red) is obtained for the parameters of Fig. 1 with k^∗ = 10⁵. The deviating full line (blue) is obtained for α = 20 and k^∗ = 10²².