FEMALE REPRODUCTIVE SYSTEM
During copulation, the penis is inserted into the female vagina. During ejaculation, the semen, containing sperm, is deposited into the vagina.

The sperm travel through the vagina to the cervix, the lower portion of the uterus, and on into the body of the uterus. During pregnancy, the uterus serves as the womb, the place the fetus grows until birth.

The sperm travel from the uterus to the oviducts (also called fallopian tubes). Fertilization takes place within the oviduct. The monthly (28-day) female menstrual cycle includes about 48 hours when fertilization can occur.

If fertilization does occur, then the tiny embryo enters the uterus and implants in the endometrium, the uterine lining. If fertilization does not occur, the unfertilized egg is passed out of the vagina during menstrual flow.