Anatomy and Histology in Hysteroscopy

Abstract

The uterus is a hollow organ, inverted pear-shaped, and located in the center of the pelvis. It is made up of three parts, the fundus, the corpus, and the cervix. The narrow portion between the corpus and the cervix is called isthmus, and its upper portion is internal orifice of the uterus, that is, anatomical internal os; the lower portion is histological internal os, which marks the transition from the endometrium to the endocervix. The size and shape of the uterus may vary with age and fertility. The uterus of normal non-childbearing women measures 7–8 cm in length, 4–5 cm in width, and 2–3 cm in thickness. The volume of uterus increases in women after parturition. The proportion of the uterus to the cervix changes with age. At adolescence, the corpus is as long as the cervix; in women of child-bearing age, the length of the corpus is about twice that of the cervix; in postmenopausal women, the corpus and the cervix are equal in length.