Changes

The ridged band, which is mucous membrane ([[mucosa]]), is joined directly to the true [[skin]] of the penis. The glans, on the other hand, does not come in direct contact with true [[skin]]. This arrangement suggests that the ridged band depends for stimulation on the tugging action of penile [[penile skin]] during intercourse. The glans is more independent of penile [[penile skin]], both functionally and physically.

The double-layered design of the foreskin does indeed permit smooth penetration and a sliding action. The [[skin]] of the penis, including the foreskin, becomes rougher during [[erection]]. This roughness is brought about by a mechanism similar to that which raises goosebumps. The extra frictional resistance brought about in this way reduces slippage of penile [[penile skin]] against female tissues. The double-layering of the foreskin is designed to offset the frictional effect of erect penile [[penile skin]] and allow for easy vaginal penetration.