Why you should use a vaginal moisturizer during your period VAGINA The vagina serves as the inferior region of the birth canal. It also serves as the passage way for the sloughed endometrium that results from menstruation and is the receptacle for Vaginal Lubrication: Vaginal Dryness, Vaginal Health, and More Vaginal Dryness: Causes and Moisturizing Treatments A frontal cross section illustration of the vagina showing the action of a vaginal lubricant which lubricates the entrance to the vagina and hydrates SuperStock Anatomy and Physiology of the Female Reproductive System Anatomy and Physiology II