Uterus

The uterus (womb) is a hollow, muscular, pear-shaped organ located in the female pelvis. It is the site of menstruation, implantation of a fertilized egg, gestation of the fetus, and labor. Its inner lining, the endometrium, cyclically thickens and sheds in response to ovarian hormones. Its thick myometrial wall contracts powerfully during childbirth. The cervix is its lower part, opening into the vagina.