The penis is the most visible part of the male sexual anatomy. It is made up of two parts, the shaft and the glans (also called the head). When a male reaches sexual climax, he ejaculates a thick fluid (semen) through the urethral opening at the tip of the penis into the vagina. The semen carries sperm cells through the vaginal canal to the uterus where the sperm seek out the female egg for fertilization. Also, when a man urinates, the flow leaves his body through the urethral opening.