文档介绍：Physical Examination Part 2 Xue Huiping
Male reproductive anatomy
This illustration represents an average normal adult human penis. The head of the penis (glans) has a covering, called the foreskin (prepuce). This covering folds in on itself, forming a double layer. The foreskin is not a `flap' of skin on the end of the penis, and it is not `useless' or `redundant' skin.
There is some natural variation in the length of the foreskin, which often covers a bit more or less of the glans than illustrated.
In an average circumcised adult man, the area of skin that is missing because of penile reduction surgery would, when erect and unfolded, measure approximately three by five inches, or a little smaller than a postcard. That is about half the total skin of the penis.
Structures of the penis
The outer foreskin layer is a continuation of the skin of the shaft of the penis.
The inner foreskin layer is not properly `skin', but mucocutaneous tissue of a unique type found nowhere else on the body.
The frenar band is the interface (join) between the outer and inner foreskin layers. When the penis is not erect, it tightens to narrow the foreskin opening. During erection, the frenar band forms a ridge that goes all the way around, about halfway down the shaft.
The reddish or purplish glans or glans penis (head of the penis) is smooth, shiny, moist and extremely sensitive.
The frenulum, or frenum, is a connecting membrane on the underside of the penis, similar to that beneath the tongue.