Definition of Penis

Penis: The external male sex organ used to copulate and ejaculate semen and to convey urine outside the body. In Latin, the word "penis" originally meant "a tail." The Latin "penis" is related to the verb pendere meaning "to hang down."

The penis contains two chambers, the corpora cavernosa, which run the length of the organ. These are filled with spongy tissue and surrounded by a membrane called the tunica albuginea. The spongy tissue contains smooth muscles, fibrous tissues, spaces, veins, and arteries. The urethra, which is the channel for urine and ejaculate, runs along the underside of the corpora cavernosa. The urethra emerges at the glans, the rounded tip of the penis. The penis is the counterpart of the clitoris in the female.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=4827
Last Editorial Review: 6/8/2004

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