* Membrane covers [[Female_Reproductive_Tract_-The_Vagina/Vestibule_-_Anatomy_%26_Physiology|vaginal]] opening except at oestrus and during [[Reproductive System - Anatomy & Physiology#Parturition|parturition]]. | * Membrane covers [[Female_Reproductive_Tract_-The_Vagina/Vestibule_-_Anatomy_%26_Physiology|vaginal]] opening except at oestrus and during [[Reproductive System - Anatomy & Physiology#Parturition|parturition]]. |