The smooth muscle

According to science this is the only muscle in the penis. It consists of small cells whose function is to relax or contract around the blood vessels supplying the corpor cavernosa with blood thus making a penis erect or flaccid.

Does anyone know if the smooth muscle has any contribution to enlargement?

Smooth Muscle and PE

Possible reason for PE induced growth

Thank you, next time I will be more weary of the search button.