Changes

The [[foreskin]] and the [[glans]] have similar functions. Both are designed to trigger nerve impulses that lead to [[erection]] and ejaculation. The [[glans ]] detects deep pressure and movement. The [[foreskin ]] detects movement through the accordion-like action of the [[ridged band]]; in addition, the outer, true [[skin]] of the foreskin has an exquisite ability to detect light touch and pin-prick. The glans lacks these abilities because it relies on the covering foreskin to provide them.

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 skin]] against [[Vagina| female tissues]]. The double-layering of the foreskin is designed to offset the frictional effect of erect [[penile skin]] and allow for easy vaginal penetration.