|The uterus or womb is the major female reproductive organ of most mammals, including humans. On one end is the cervix, which opens into the vagina; and the other end is connected on both sides to the fallopian tubes (forming a Y-shaped structure). The term uterus is commonly used within the medical and related professions, while womb is the more common colloquial usage.
The main function of the uterus is to accept a fertilized egg that becomes implanted into the rich uterus lining called endometrium, and derives nourishment from blood vessels that develop exclusively for this purpose. The fertilized egg becomes an embryo, develops into a fetus and gestates until childbirth.
Due to anatomical barriers such as the pelvis, the uterus is pushed partially into the abdomen due to its expansion during pregnancy. In women who are not pregnant, the lining is shed about once a month if an egg is not fertilized. The shedding is called menstruation.