What is the shape of external os in nulliparous female ?
circular
transvers
veical
oval
In a nulliparous woman, i.e. a woman who has not borne children, the external os is small and circular. However, in multiparous women, the external os is bounded by anterior and posterior lips, both of which are in contact with the posterior wall of the vagina. Ref : B D Chaurasia's Human Anatomy , seventh edition, volume 2, pg.no.421.
Abdomen and pelvis