The World Health Organization states that 'he frenulum forms the interface between the outer and inner foreskin layers, and when the penis is not erect, it tightens to narrow the foreskin opening. The foreskin is attached to the glans by a frenulum, a highly vascularized tissue of the penis. Like the eyelid, the foreskin is free to move after it separates from the glans, which usually occurs before or during puberty. The mucocutaneous zone occurs where the outer and inner foreskin meet. The outside of the foreskin is a continuation of the skin on the shaft of the penis, but the inner foreskin is a mucous membrane like the inside of the eyelid or the mouth.
