Defence Mechanisms of Oral and Genital Mucosae

The skin and orogenital mucosae are the body's first line of defence and offer protective barriers against infection. Being the point of entry to the gastrointestinal and genitourinary tract, respectively, oral and genital mucosae are at risk of developing various sexually transmitted infections. To understand the pathogenesis of sexually transmitted diseases, clinicians should possess basic knowledge of the mucosal defence mechanisms involved against microbial invasion. This chapter describes the defence mechanisms of oral mucosa, vaginal mucosa and penile mucosa. Mechanisms of oral mucosal defence include physical barriers (epithelium and lamina propria), non-specific bacterial balance, saliva containing both non-specific and specific antimicrobial factors and specific immune humoral and cell-mediated defence mechanisms. Studies on the immunology of the human penile urethra indicate that this mucosal site is immunologically competent and capable of mounting both innate and cellular and humoral adaptive immunological responses.