The diagram shows the female reproductive system with four labelled parts. Label I points to the fallopian tube (oviduct), label II points to the uterus, label III points to the cervix, and label IV points to the vagina.
The part labelled II is the uterus. It is the large, hollow, pear-shaped muscular organ located in the centre of the diagram. The uterus is where a fertilised egg implants and develops during pregnancy. Its thick muscular walls (myometrium) contract during labour to push the baby out, while its inner lining (endometrium) thickens each menstrual cycle in preparation for possible implantation. If fertilisation does not occur, this lining is shed during menstruation.
