The internal orifice of the uterus (or internal orifice of the cervix uteri or internal os) is an interior narrowing of the uterine cavity. It corresponds to a slight constriction known as the isthmus that can be observed on the surface of the uterus about midway between the apex and base.
Famous quotes containing the word internal:
“I believe that there was a great age, a great epoch when man did not make war: previous to 2000 B.C. Then the self had not really become aware of itself, it had not separated itself off, the spirit was not yet born, so there was no internal conflict, and hence no permanent external conflict.”
—D.H. (David Herbert)