Mechanical state of an adhered RBC in shear flow. (A) An RBC locally adhered while under a shear stress of τ = 0.7 dynes/cm². Note the encircled “adhered tip.” (B) Area deformation of the skeleton, at the adhered tip, as measured by λ_1, λ₂, where λ_i, with i = 1,2 are the 2 principal stretches in the plane of the membrane; this means that the fractional area change of the skeleton would be α = λ₁λ₂ − 1. Note that the area deformation of the bilipid membrane is 0. (C) The contact pressure at the adhered tip, which when negative, represents a stress that tends to pull apart the skeleton and membrane. (D) The model is that of a viscous bilipid membrane attached to the skeleton via discrete “pinning points” representing the transmembrane protein and peripheral anchoring proteins. Note that the membrane proteins are mobile within the membrane via viscous drag; hence, the skeleton may “remodel” and, thereby, alter the areal density of pinning points. T_m and T_s are the tensions in the membrane and skeleton, respectively. Details can be found in Asaro et al.^12,13  SC, suspension complex.