Figure 6.

Radial displacements of internal rim (radius R_d), outer boundary (radius R_a), and points at initial radius R₀ = 190 µm during one cycle; for two extreme cases: condition with no muscle constituent (m = 0), and with only muscle constituent within the ring (m = 1). Due to hysteretic characteristic of surfactant, radial displacement curves are not symmetric with respect to the middle line (end of inspiration), except for the outer boundary, with asymmetry more pronounced for the domain closer to internal rim. Displacements and asymmetry are smaller for m = 1.