Functions:
Main functions of penis are urination, erection, and ejaculation.
Diseases:
Disease conditions like spots, lumps or rashes of penis are common. Priapism means painful erection. Phimosis is a condition where foreskin of the penis cannot be retracted. Curve penis. Balanitis is the skin disease affecting the penis. Hypospadias in this the opening of the urethra is not located at the tip of the penis, male urinary incontinence, testicular cancer. These all are the various disease conditions of penis.
Interesting Facts:
Humans have the largest penis out of all primates. The studies have shown that the average erect penis size is 5.1 inches long. Nothing can make the penis bigger. All men have a line going down their penis over their testicles. It forms when foetus is in the uterus. In women, the seam becomes the inner lips of the vagina. In men, the seam encloses the urethra along the length of the penis.