Guide to the Penis

A man’s genital anatomy is much more than his penis. The male penis, which is the shaft that hangs outside of his body, generally lies limp. When arousal occurs and the penis fills with blood, however, it becomes erect. The testicles lie on either side of the penis. Their purpose is two-fold: To produce both sperm and the sexual hormone, testosterone. The testicles are surrounded by a thin membrane of skin called the scrotum. The scrotum acts as a temperature-control center for the testicles, keeping them slightly cooler than the rest of the body to ensure a pleasant climate for sperm. After the body produces sperm in the testicles, they are held in the epididymus, which is adjacent to the testicles, and then the sperm through a tube called the vas deferens. From the vas deferens, of course, the sperm travel to the penis to be ejaculated. The urethra is a tube that runs within the penis to transport urine and semen. And, surrounding the urethra at the penis’s base, is the much talked about gland called the prostate. Although the prostate can be a source of pleasure, its reproductive purpose is to create a fluid that contains and nourishes sperm. This white, sticky fluid combines with sperm to create the ejaculatory substance known as semen. If you think the penis is complicated, though…check out all the parts that compose the vagina in our other videos!