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.
Article Sections. Chlamydia trachomatis is a gram-negative bacterium that infects the columnar epithelium of the cervix, urethra, and rectum, as well as nongenital sites such as the lungs and eyes.