Changes

Penile [[Penile skin]] has two important characteristics, apparent only on [[erection]]. Firstly penile [[penile skin]] tenses, stiffens and shortens, firming up the connection between [[shaft skin]] and ridged band. This change allows for the transmission of movement from the base of the erect penis to the ridged band.

Secondly, penile [[penile skin]] undergoes a marked frictional change, brought about by stiff, forward-pointing [[skin]] folds. The mechanism is similar to that which raises goosebumps.

The changes in penile [[penile skin]] are brought about by contraction of the [[Dartos]] muscle. Between them, stiffening and frictionality ensure that the ridged band is instantly alerted to changes in position of the penis within the vagina.