Menstruation, periodic discharge from the vagina of blood, secretions, and disintegrating mucous membrane that had lined the uterus. 1  The biological significance of the process in humans can best be explained by reference to the reproductive function in other mammals.
Chlamydia is a common sexually transmitted disease (STD) caused by infection with Chlamydia trachomatis. It can cause cervicitis in women and urethritis and proctitis in both men and women.
Causes. Chlamydia is caused by bacteria and is most commonly spread through vaginal, oral and anal sex. It's also possible for a mother to spread chlamydia to her child during delivery, causing pneumonia or a serious eye infection in her newborn.auses. Chlamydia is caused by bacteria and is most commonly spread through vaginal, oral and anal sex. It's also possible for a mother to spread chlamydia to her child during delivery, causing pneumonia or a serious eye infection in her newborn.