The main female reproductive organs are the uterus, ovaries, fallopian tubes, and vagina. The uterus, a hollow muscular organ about 3 inches long located deep inside the pelvic cavity is home to the developing fetus. The neck of the uterus (cervix) projects into the vagina, a muscular tube about 4 inches long that receives the penis and sperm and serves as the birth canal.
The fallopian tubes, a pair of structures each about 4 inches long, join the uterus near the top. Their flared ends lie near the ovaries, paired almond-shaped glands that produce ova (eggs) and female hormones. After an ovum is expelled into the pelvic cavity, it passes through a fallopian tube into the uterus. If the egg has been fertilized by a sperm, it implants in the uterus and gestation begins.