The penis is a male reproductive organ that plays a key role in sexual reproduction. It is made up of erectile tissue, which can fill with blood to become firm and erect during arousal. This allows for penetration during sexual intercourse, which is essential for the transfer of sperm to the female reproductive system. In addition to its reproductive function, the penis also serves as a conduit for urine to exit the body. It is connected to the urethra, a tube that runs through the penis and carries both urine and semen. Understanding the anatomy and function of the penis is important for sexual health and education.