Know your body

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.

A duct, or tube, that transports fluids from the inside of the body to the outside. In both men and women, the urethra is connected to the bladder and is used to pass urine out of the body. In males, however, the urethra is also connected to the "accessory glands," which produce semen, and to the vas deferens, the duct that brings the sperm from the epididymis.

The testicles are located below the penis and begin producing male sex cells called sperm and testosterone, the male sex hormone after puberty.

A pouch of skin called the scrotum covers the testicles. The scrotum and the muscles surrounding it can pull the testicles toward the body when they are too cold and relax away from the body when the testicles are too warm. This is important because sperm needs to be maintained at an appropriate temperature to be able to fertilize female eggs. The scrotum also holds the epididymis.

The epididymis stores the sperm after the testicles produce them, and the vas deferens transports the sperm from the epididymis to the urethra.