How does the sexual arousal mechanism in women facilitate fecundation?

During sexual arousal in women the vagina secretes substances to neutralize its acidity therefore allowing the survival of sperm cells within it. During the female fertile period hormones make the mucus that covers the internal surface of the uterus less viscous to help the passage of sperm cells to the uterine tubes. During copulation the uterine cervix advances in the vagina to facilitate the entering of male gametes by the cervical canal.