The external sexual organs of the female are the clitoris, the mons, the inner lips, the outer lips, and the vaginal opening. Collectively these are referred to as the vulva. The clitoris is an extremely sensitive organ and is very important in female sexual response. Clitoridectomy and infibulation are rituals that involve cutting of the clitoris and other parts of the vulva and are practiced widely in some African nations and elsewhere. Another external structure is the hymen, which has taken on great symbolic significance as a sign of virginity, although its absence is not a reliable indicator that a woman is not a virgin. The important internal structures are the vagina, which receives the penis during coitus; the uterus, which houses the developing fetus; the ovaries, which produce eggs and manufacture sex hormones; and the fallopian tubes, which convey the egg to the uterus. The breasts of the female also function in sexual arousal and may have great symbolic significance.

The external sexual organs of the male are the penis and the scrotum. The penis contains three spongy bodies which, when filled with blood, produce an erection. Circumcision, or surgical removal of the foreskin of the penis, is a practice debated in the United States but may have some health advantages. The scrotum contains the testes, which are responsible for the manufacture of sperm (in the seminiferous tubules) and sex hormones (in the interstitial cells). Sperm pass out of the testes during ejaculation via the vas deferens, the ejaculatory duct, and the urethra. The seminal vesicles manufacture most of the fluid that mixes with the sperm to form semen. The prostate also contributes secretions.

Breast cancer is the second most common form of cancer in women. All women should do a monthly self-exam, because the earlier a lump is detected, the greater the chances of complete recovery. The Pap test is used to detect cervical cancer. Prostate cancer is the second most common form of cancer in men, but it generally affects older men. Cancer of the testes, although rare, is the most common cancer in men between the ages of 29 and 35. Men should do a monthly testicular self-exam, just as women should do a monthly breast self-exam.