Uterus is a thick-walled muscular bag-like organ of the female reproductive system. It is the site where the embryo gets implanted and develops during the nine months of pregnancy. The uterine wall is differentiated into three layers - outer perimetrium, middle myometrium and inner endometrium. The endometrial layer's inner lining is richly supplied with blood vessels and glands. The lower tip of uterus is called the cervix.